Fermentations

Clin Sci (Lond), 1997 Aug, 93(2), 109 - 12
Fermentable dietary fibre, intestinal microflora and plasma hormones in the rat; Ghatei MA et al.; 1 . Conventional and germ-free rats were fed a fibre-free elemental diet with or without the addition of fermentable dietary fibres . We have previously reported that fibre was associated with greatly increased epithelial cell proliferation, but only in the conventional group, implying that it is the breakdown of fibre by the colonic microflora that is the main determinant of mucosal proliferation in the hind gut . The relationship of these changes to various plasma hormones implicated in intestinal growth control are described in this paper . 2 . The most dramatic finding was that plasma levels of enteroglucagon and peptide YY were greatly increased in the germ-free groups . The response of these rats to fibre differed in that fibre decreased levels of enteroglucagon and peptide YY in the germ-free animals, but increased them in the conventional rats . Gastrin and insulin levels were significantly lowered in the fibre-supplemented groups, but were not affected by the microflora . 3 . These results corroborate our previous findings that the effects of fibre and its fermentation are dynamically complex, and demonstrate that, like proliferation, direct effects and indirect fermentation-derived effects on plasma hormones also coexist.

Appl Microbiol Biotechnol, 1997 Aug, 48(2), 141 - 8
Production of D-ribose by fermentation; De Wulf P et al.; The production of D-ribose by fermentation has received much attention lately, possibly because of the use of this pentose to synthesize antiviral and anticancer drugs . This review briefly outlines the methods that have been used to synthesize D-ribose since it was identified in yeast RNA, and focuses in particular on the latest developments in D-ribose fermentation, which have led to D-ribose yields that exceed 90 g/1 . Furthermore, the various transketolase-deficient D-ribose-producing mutants that are used, and the biochemical and genetic rationales applied to select them or to enhance their D-ribose productivities, are dealt with . Attention is also drawn to the unusual pleiotropic characteristics of the mutant strains, as well as to the industrial and academic applications of D-ribose.

Glycoconj J, 1997 Aug, 14(5), 669 - 76
Cellulose depolymerization to glucose and other water soluble polysaccharides by shear deformation and high pressure treatment; Kokorevics A et al.; The simultaneous action of shear deformation and high pressure (SDHP) creates changes in the structure of wood and its main components (cellulose, hemicelluloses, lignin) . The formation of water and alkali soluble polysaccharides under SDHP action, proceeds in seconds in the solid state, without the use of any reagents and solvents . Therefore, SDHP seems to be a technologically safe method and friendly to the environment . The amorphization of cellulose crystallites and depolymerization of cellulose chains were observed under a wide range of pressures (1-6 GPa), both for cellulose samples and the cellulose part of wood . Similar depolymerization occurs in the hemicellulose part of wood . The decomposition of polysaccharides under SDHP causes the formation of the water soluble part, whose content increases with pressure and the applied shear deformation . A maximum solubility of 40% and 55% was registered at 6 GPa following treatment of cellulose and birch wood samples . A higher output in the case of wood can be explained by a specific role of lignin under SDHP, which acts as a 'grinding stone' during cellulose and hemicelluloses destruction . As shown by high-performance size exclusion chromatography, the water soluble fraction obtained from cellulose contained glucose (2.6%), cellobiose (9.6%), cellotriose (16.6%) and other higher water soluble oligomers (71%) . Almost complete dissolution (98%) of the treated cellulose sample can be achieved by extraction with 10% NaOH solution . The SDHP treated birch wood was subjected to submerged fermentation (with Trichoderma viride), and a 13% output of proteins was obtained . In this case, the water soluble part played the role of the so called 'start sugars'.

Antonie Van Leeuwenhoek, 1997 Aug, 72(2), 101 - 9
Formation of formate and hydrogen, and flux of reducing equivalents and carbon in Ruminococcus flavefaciens FD-1; Shi Y et al.; A pathway for conversion of the metabolic intermediate phosphoenolpyruvate (PEP) and the formation of acetate, succinate, formate, and H2 in the anaerobic cellulolytic bacterium Ruminococcus flavefaciens FD-1 was constructed on the basis of enzyme activities detected in extracts of cells grown in cellulose- or cellobiose-limited continuous culture . PEP was converted to acetate and CO2 (via pyruvate kinase, pyruvate dehydrogenase, and acetate kinase) or carboxylated to form succinate (via PEP carboxykinase, malate dehydrogenase, fumarase, and fumarate reductase) . Lactate was not formed even during rapid growth (batch culture, mu = 0.35/h) . H2 was formed by a hydrogenase rather than by cleavage of formate, and 13C-NMR and 14C-exchange reaction data indicated that formate was produced by CO2 reduction, not by a cleavage of pyruvate . The distribution of PEP into the acetate and succinate pathways was not affected by changing extracellular pH and growth rates within the normal growth range . However, increasing growth rate from 0.017/h to 0.244/h resulted in a shift toward formate production, presumably at the expense of H2 . This shift suggested that reducing equivalents could be balanced through formate or H2 production without affecting the yields of the major carbon-containing fermentation endproducts.

Arch Microbiol, 1997 Oct, 168(4), 297 - 301
Thiosulfate as a metabolic product: the bacterial fermentation of taurine; Denger K et al.; Thiosulfate (S2O32-) is a natural product that is widely utilized in natural ecosystems as an electron sink or as an electron donor . However, the major biological source(s) of this thiosulfate is unknown . We present the first report that taurine (2-aminoethanesulfonate), the major mammalian solute, is subject to fermentation . This bacterial fermentation was found to be catalyzed by a new isolate, strain GKNTAU, a strictly anaerobic, gram-positive, motile rod that formed subterminal spores . Thiosulfate was a quantitative fermentation product . The other fermentation products were ammonia and acetate, and all could be formed by cell-free extracts.

Arch Microbiol, 1997 Oct, 168(4), 290 - 6
Regulatory O2 tensions for the synthesis of fermentation products in Escherichia coli and relation to aerobic respiration; Becker S et al.; In an oxystat, the synthesis of the fermentation products formate, acetate, ethanol, lactate, and succinate of Escherichia coli was studied as a function of the O2 tension (pO2) in the medium . The pO2 values that gave rise to half-maximal synthesis of the products (pO0 . 5) were 0.2-0.4 mbar for ethanol, acetate, and succinate, and 1 mbar for formate . The pO0.5 for the expression of the adhE gene encoding alcohol dehydrogenase was approximately 0.8 mbar . Thus, the pO2 for the onset of fermentation was distinctly lower than that for anaerobic respiration (pO0.5 </= 5 mbar), which was determined earlier . An essential role for quinol oxidase bd in microaerobic growth was demonstrated . A mutant deficient for quinol oxidase bd produced lactate as a fermentation product during growth at microoxic conditions (approximately 10 mbar O2), in contrast to the wild-type or a quinol-oxidase-bo-deficient strain . In the presence of nitrate, the amount of lactate was largely decreased . Therefore, under microoxic conditions, the pO2 appears to be too high for (mixed acid) fermentation to function and too low for aerobic respiration by quinol oxidase bo.

Appl Environ Microbiol, 1997 Sep, 63(9), 3399 - 404
Metabolic responses of pyruvate decarboxylase-negative Saccharomyces cerevisiae to glucose excess; Flikweert MT et al.; In Saccharomyces cerevisiae, oxidation of pyruvate to acetyl coenzyme A can occur via two routes . In pyruvate decarboxylase-negative (Pdc-) mutants, the pyruvate dehydrogenase complex is the sole functional link between glycolysis and the tricarboxylic acid (TCA) cycle . Such mutants therefore provide a useful experimental system with which to study regulation of the pyruvate dehydrogenase complex . In this study, a possible in vivo inactivation of the pyruvate dehydrogenase complex was investigated . When respiring, carbon-limited chemostat cultures of wild-type S . cerevisiae were pulsed with excess glucose, an immediate onset of respiro-fermentative metabolism occurred, accompanied by a strong increase of the glycolytic flux . When the same experiment was performed with an isogenic Pdc- mutant, only a small increase of the glycolytic flux was observed and pyruvate was the only major metabolite excreted . This finding supports the hypothesis that reoxidation of cytosolic NADH via pyruvate decarboxylase and alcohol dehydrogenase is a prerequisite for high glycolytic fluxes in S . cerevisiae . In Pdc- cultures, the specific rate of oxygen consumption increased by ca . 40% after a glucose pulse . Calculations showed that pyruvate excretion by the mutant was not due to a decrease of the pyruvate flux into the TCA cycle . We therefore conclude that rapid inactivation of the pyruvate dehydrogenase complex (e.g., by phosphorylation of its E1 alpha subunit, a mechanism demonstrated in many higher organisms) is not a relevant mechanism in the response of respiring S . cerevisiae cells to excess glucose . Consistently, pyruvate dehydrogenase activities in cell extracts did not exhibit a strong decrease after a glucose pulse.

J Endocrinol, 1997 Aug, 154(2), 275 - 83
Effects of season, protein and nutritional state on glucose tolerance during an annual cycle of growth in young red deer stags; McMahon CD et al.; Two hypotheses were tested in gonad-intact, young (aged 6-18 months), growing red deer stags during an annual growth cycle . First, that glucose clearance rate is faster during summer than during winter . Secondly, that increased dietary protein availability will enhance winter growth . Stags were randomly assigned into one of two groups: group 1 (n = 5) had 16% while group 2 (n = 6) had 48% of dietary protein naturally protected against fermentative degradation in the rumen . Total crude protein and energy remained similar for each diet (12 and 14% respectively for protein and 11 MJ metabolisable energy/kg dry matter) . Stags were kept indoors in individual pens for 12 months and given monthly intravenous glucose tolerance tests (IVGTT), at a dose of 200 mg/kg, in the fed and fasted (48 h) states to determine both growth and steady-state tissue requirements . Protein level had no effect on food intake, weight gain, insulin kinetics, or glucose clearance rate . In the fed state, insulin peak (highest level' after IVGTT) increased (P < 0.01) from October (139 pmol/l) to December (247 pmol/l) (S.E.D . = 42) and remained elevated during the summer, before declining (P < 0.01) from February (223 pmol/l) to April (130 pmol/l) (S.E.D . = 25) . Glucose clearance rate was faster (P < 0.05) in December (1.69 litres/min) than June (0.61 litres/min) in the fed state (S.E.D . = 0.30), and decreased (P < 0.05) from February (1.75 litres/min) to April (0.92 litres/min) (S.E.D . = 0.39) . During fasting, the pattern of glucose clearance was similar to that observed in the fed state, but the amplitude was lower, while the pattern for insulin peak was similar to that of the fed state . We concluded first, that additional protected protein does not benefit growth during winter . Secondly, we concluded from the fasted, steady-state data that stags are insulin resistant during summer . Thirdly, despite insulin resistance, data on the fed state demonstrated that stags have higher tissue energy requirements during summer growth.

Cell Tissue Res, 1997 Oct, 290(1), 61 - 9
Distribution of enteroglucagon- and peptide YY-immunoreactive cells in the intestinal mucosa of germ-free and conventional mice; Arantes RM et al.; There are evidences that microflora modulates endocrine cells in the gastrointestinal tract . In the present study we investigated the distribution of EG- and PYY-immunoreactive cells throughout the intestine of adult male NMRI conventional and germ-free mice . EG-immunoreactive cells were significantly more frequent in the proximal and middle colon than in the remainder of the intestine in both groups . In germ-free animals, these cells were more frequent in the cecum and less frequent in the distal ileum compared to conventional mice . PYY-immunoreactive cells were more frequent in the distal colon than in the remainder of the intestine in both groups, but they were significantly more frequent in the middle and distal colon of germ-free animals than in that of conventional counterparts . The number of EG-immunoreactive cells was 4.5-fold higher than the number of PYY-immunoreactive cells in the cecum of germ-free mice . The present results indicate the existence of an inverse gradient of EG- and PYY-immunoreactive cells along the colon, which is not significantly changed in the absence of a microflora . PYY production seems to be more significant in the distal colon . The cecum and the proximal portion of the colon are probably the regions of greatest functional importance for EG production, which is related to the microflora and probably to fermentation products, whether or not the effect of this peptide is trophic or antitrophic.

Proc Natl Acad Sci U S A, 1997 Sep 2, 94(18), 9608 - 13
Pyruvate ferredoxin oxidoreductase from the hyperthermophilic archaeon, Pyrococcus furiosus, functions as a CoA-dependent pyruvate decarboxylase; Ma K et al.; Pyruvate ferredoxin oxidoreductase (POR) has been previously purified from the hyperthermophilic archaeon, Pyrococcus furiosus, an organism that grows optimally at 100 degrees C by fermenting carbohydrates and peptides . The enzyme contains thiamine pyrophosphate and catalyzes the oxidative decarboxylation of pyruvate to acetyl-CoA and CO2 and reduces P . furiosus ferredoxin . Here we show that this enzyme also catalyzes the formation of acetaldehyde from pyruvate in a CoA-dependent reaction . Desulfocoenzyme A substituted for CoA showing that the cofactor plays a structural rather than a catalytic role . Ferredoxin was not necessary for the pyruvate decarboxylase activity of POR, nor did it inhibit acetaldehyde production . The apparent Km values for CoA and pyruvate were 0.11 mM and 1.1 mM, respectively, and the optimal temperature for acetaldehyde formation was above 90 degrees C . These data are comparable to those previously determined for the pyruvate oxidation reaction of POR . At 80 degrees C (pH 8.0), the apparent Vm value for pyruvate decarboxylation was about 40% of the apparent Vm value for pyruvate oxidation rate (using P . furiosus ferredoxin as the electron acceptor) . Tentative catalytic mechanisms for these two reactions are presented . In addition to POR, three other 2-keto acid ferredoxin oxidoreductases are involved in peptide fermentation by hyperthermophilic archaea . It is proposed that the various aldehydes produced by these oxidoreductases in vivo are used by two aldehyde-utilizing enzymes, alcohol dehydrogenase and aldehyde ferredoxin oxidoreductase, the physiological roles of which were previously unknown.

Cancer Res, 1997 Sep 1, 57(17), 3697 - 707
Induction of caspase-3 protease activity and apoptosis by butyrate and trichostatin A (inhibitors of histone deacetylase): dependence on protein synthesis and synergy with a mitochondrial/cytochrome c-dependent pathway; Medina V et al.; The induction of apoptosis of tumor cells by the colonic fermentation product butyrate is thought to be an important mechanism in protection against colorectal cancer . Because a major action of butyrate is to inhibit histone deacetylase (leading to chromatin relaxation and altered gene expression), butyrate may induce apoptosis by derepression of specific cell death genes . Here we show that butyrate and trichostatin A (a more selective inhibitor of histone deacetylase) induce the same program of apoptosis in Jurkat lymphoid and LIM 1215 colorectal cancer cell lines that is strictly dependent on new protein synthesis (within 10 h) and that leads to the conversion of the proenzyme form of caspase-3 to the catalytically active effector protease (within 16 h) and apoptotic death (within 24 h) . Cells primed with a low concentration of butyrate that itself did not induce activation of caspase-3 or apoptosis were, nevertheless, rendered highly susceptible to induction of apoptosis by staurosporine (an agent that has recently been shown to act by causing mitochondrial release of cytochrome c) . Synergy between butyrate and staurosporine was due to the presence of a factor in the cytosol of butyrate-primed cells which enhanced over 7-fold the activation of caspase-3 induced by the addition of cytochrome c and dATP to isolated cytosol . We propose that changes at the level of chromatin structure, induced by a physiological substance butyrate, lead to the expression of a protein that facilitates the pathway by which mitochondria activate caspase-3 and trigger apoptotic death of lymphoid and colorectal cancer cells.

Infect Immun, 1997 Sep, 65(9), 3799 - 805
Shiga toxin-producing Escherichia coli isolates from cases of human disease show enhanced adherence to intestinal epithelial (Henle 407) cells; Paton AW et al.; Shiga toxin-producing Escherichia coli (STEC) strains are a diverse group of organisms which are known to cause diarrhea and hemorrhagic colitis in humans . We have recently described a large food-borne outbreak of STEC disease caused by contaminated semidry fermented sausage (A . W . Paton, R . Ratcliff, R . M . Doyle, J . Seymour-Murray, D . Davos, J . A . Lanser, and J . C . Paton, J . Clin . Microbiol . 34:1622-1627, 1996) . STEC strains belonging to several O serotypes were isolated from the contaminated food source, but of these, only a subset were isolated from patients with diarrhea or hemolytic-uremic syndrome (HUS) . In the present study, we characterized these STEC isolates with respect to the presence of putative virulence-associated genes and the capacity to adhere to a human intestinal epithelial cell line (Henle 407) . The O111:H- STEC strain 95NR1 (isolated from one of the outbreak HUS patients) was shown to adhere to Henle 407 cells in a dose-dependent, mannose-resistant fashion . Microscopic examination revealed a diffuse pattern of adherence for this as well as several other STEC strains . Interestingly, the adherence of STEC strains from HUS cases (both outbreak related and sporadic) was significantly greater than that of STEC strains found in the contaminated food source but not found in any patients . These studies support the hypothesis that an enhanced capacity to adhere to intestinal cells is one of the factors which distinguishes human-virulent STEC strains from those of lesser clinical significance.

Poult Sci, 1997 Sep, 76(9), 1220 - 6
Preservation of hatchery waste by lactic acid fermentation . 2 . Large-scale fermentation and feeding trial to evaluate feeding value; Deshmukh AC et al.; Two waste streams from a Leghorn hatchery were preserved and recycled by fermentation with a by-product carbohydrate and extrusion processing into new feed ingredients that were evaluated with broiler chickens . Cockerel chicks (CC) and a 60:40 ratio of CC:shell waste (CC:SW) were fermented in 189-L barrels for 21 d following grinding, then mixing with a liquid culture (0.2%) and carbohydrate source at 15 and 16.66%, respectively . At 2 wk, pH was 4.44 and 5.09 for the CC and CC:SW products compared with higher values of 6.54 and 6.98 for the raw ingredients at the onset . Negligible hydrogen sulfide and no ammonia gas were recorded during the fermentation period . At 21 d, the fermented CC and CC:SW were extruded, dried, and ground to meals containing CP and TMEn levels of 47.4%, 3,187 kcal/kg, and 33.1%, 2,696 kcal/kg, respectively . Broiler chickens were fed a control diet and the CC (5 and 10%) and CC:SW (2.5 and 5%) ingredient diets with corn and soybean meal for 6 wk to evaluate feeding value and carcass yield . Body weight, gain and feed conversion at 42 d for birds fed diets supplemented with CC or CC:SW at all levels were comparable to those of the control . Diets supplemented with hatchery by-product had no negative effect on carcass measurements except ready to cook carcass and wing yield, which were significantly greater for the 10% CC:SW birds than for the control . These data indicate that nutrient dense hatchery by-products can be preserved with fermentation up to 21 d and support broiler live performance and carcass yield as dietary ingredients equal to or better than a corn-soybean meal control.

Mol Biochem Parasitol, 1997 Sep, 88(1-2), 163 - 74
Isolation of a cDNA encoding Fasciola hepatica cathepsin L2 and functional expression in Saccharomyces cerevisiae; Dowd AJ et al.; Cathepsin L2 is a major cysteine proteinase secreted by adult Fasciola hepatica . The enzyme differs from other reported cathepsin Ls in that it can cleave peptide substrates that contain proline in the P2 position . A cDNA was isolated from an expression library by immunoscreening with antiserum prepared against purified native cathepsin L2 . This cDNA was sequenced and shown to encode a complete preprocathepsin L proteinase . Functionally active recombinant cathepsin L proteinase was expressed and secreted by Saccharomyces cerevisiae transformed with the cDNA . The recombinant enzyme was purified from large-scale fermentation broths using ultrafiltration and gel filtration chromatography on Sephacryl S200 HR columns . NH2-terminal amino acid sequencing showed that the cleavage point for activation of the recombinant pro-enzyme is identical to that of the F . hepatica-produced cathepsin L2 . The mature active recombinant proteinase behaved similarly to the native enzyme when analysed by SDS-PAGE, immunoblotting and zymography and also cleaved peptides containing proline in the P2 position . Finally, the recombinant cathepsin L2 cleaved fibrinogen to form a fibrin clot, a property we described for F . hepatica cathepsin L2.

J Med Chem, 1997 Aug 15, 40(17), 2755 - 61
6A-O-{(4-biphenylyl)acetyl}-alpha-, -beta-, and -gamma-cyclodextrins and 6A-deoxy-6A-{{(4-biphenylyl)acetyl}amino}-alpha-, -beta-, and -gamma-cyclodextrins: potential prodrugs for colon-specific delivery; Uekama K et al.; Cyclodextrins (CyDs) are known to be fermented to small saccharides by colonic microflora, whereas they are only slightly hydrolyzable and thus are not easily absorbed in the stomach and small intestine . This property of CyDs is particularly useful for colon-specific delivery of drugs . In this study, an antiinflammatory 4-biphenylylacetic acid (BPAA) was selectively conjugated onto one of the primary hydroxyl groups of alpha-, beta-, and gamma-CyDs through an ester or amide linkage, 6A-O-{(4-biphenylyl)acetyl{-alpha-, -beta-, and -gamma-CyDs (1-3) and 6A-deoxy-6A-{{(4-biphenylyl)acetyl}amino}-alpha-, -beta-, and -gamma-CyDs (4-6) . In rat cecal and colonic contents (10%, w/v), 1 and 3 released more than 95% of BPAA within 1-2 h, and 2 released about 50% of the drug within 12 h . The amide prodrugs, 4-6, did not release BPAA in the cecal contents, but gave BPAA/maltose or BPAA/triose conjugates linked through an amide bond . On the other hand, these prodrugs were found to be stable in the contents of rat stomachs and small intestines, in intestinal or liver homogenates, and in rat blood . The serum levels of BPAA increased about 3 h after oral administration of 1 and 3 to rats, accompanying a marked increase in the serum levels, whereas 2 and 4-6 resulted in little increase of the serum levels . These facts suggest that BPAA is released after the ring opening of CyDs followed by the ester hydrolysis, and the BPAA activation takes place site-specifically in the cecum and colon . Therefore, the present CyD prodrug approach provides a versatile means of constructing a novel colon-specific drug delivery system.

Wien Klin Wochenschr, 1997 Aug 8, 109(14-15), 578 - 83
Genital mycoplasma infections; Taylor-Robinson D et al.; Since 1937, 13 Mycoplasma species, two Acholeplasma species, and one Ureaplasma species have been isolated from humans . Six of these have the urogenital tract as the primary site of colonisation but others, which have the oropharynx and respiratory tract as the primary site, are found occasionally in the urogenital tract because of orogenital contact . Mycoplasma hominis was the first to be isolated and is most strongly associated with bacterial vaginosis (BV), together with a variety of other bacteria . Its involvement in pelvic inflammatory disease (PID) and other conditions may be as part of BV, although when isolated in pure culture from the blood of women who have postpartum or postabortal fever there is no reason to suspect its aetiological role . There is evidence for an aetiological role for Ureaplasma urealyticum organisms (ureaplasmas) in acute non-gonococcal urethritis (NGU) and particularly chronic NGU in men, but they rank third to Chlamydia trachomatis and M . genitalium . Whether the association of ureaplasmas with miscarriage and preterm labour is in the context of BV is not clear . Of no doubt, however, is the ability of ureaplasmas to cause septic arthritis in hypogammaglobulinaemic patients and there is evidence that they may cause some cases of sexually acquired reactive arthritis . The advent of polymerase chain reaction technology has seen an advance in the understanding of the role of M . genitalium; there is strong evidence that it is one of the causes of both acute and chronic NGU independent of C . trachomatis . There is some support for the role of M . genitalium in PID, but this needs to be substantiated . Other mycoplasmas, for example M . fermentans, M . pivum, M . primatum, M . penetrans, M . spermatophilum and even M . pneumoniae have the capacity to cause urogenital tract disease but there is no evidence to indicate that they do so.

JAMA, 1997 Aug 6, 278(5), 412 - 7
Biological warfare . A historical perspective; Christopher GW et al.; The deliberate use of microorganisms and toxins as weapons has been attempted throughout history . Biological warfare has evolved from the crude use of cadavers to contaminate water supplies to the development of specialized munitions for battlefield and covert use . The modern development of biological agents as weapons has paralleled advances in basic and applied microbiology . These include the identification of virulent pathogens suitable for aerosol delivery and industrial-scale fermentation processes to produce large quantities of pathogens and toxins . The history of biological warfare is difficult to assess because of a number of confounding factors . These include difficulties in verification of alleged or attempted biological attacks, the use of allegations of biological attacks for propaganda purposes, the paucity of pertinent microbiological or epidemiologic data, and the incidence of naturally occurring endemic or epidemic diseases during hostilities . Biological warfare has been renounced by 140 nations, primarily for strategic and other pragmatic reasons . International diplomatic efforts, including the 1972 Biological Weapons Convention, have not been entirely effective in preventing the enhancement and proliferation of offensive biological warfare programs . The threats posed by biological weapons are likely to continue into the future.

Dig Dis Sci, 1997 Aug, 42(8), 1571 - 9
Colonic sulfide in pathogenesis and treatment of ulcerative colitis; Roediger WE et al.; A role for colonic sulfide in the pathogenesis and treatment of ulcerative colitis (UC) has emerged based on biochemical, microbiological, nutritional, toxicological, epidemiological, and therapeutic evidence . Metabolism of isolated colonic epithelial cells has indicated that the bacterial short-chain fatty acid n-butyrate maintains the epithelial barrier and that sulfides can inhibit oxidation of n-butyrate analogous to that observed in active UC . Sulfur for fermentation in the colon is essential for n-butyrate formation and sulfidogenesis aids disposal of colonic hydrogen produced by bacteria . The numbers of sulfate-reducing bacteria and sulfidogenesis is greater in UC than control cases . Sulfide is mainly detoxified by methylation in colonic epithelial cells and circulating red blood cells . The enzyme activity of sulfide methylation is higher in red blood cells of UC patients than control cases . Patients with UC ingest more protein and thereby sulfur amino acids than control subjects . Removing foods rich in sulfur amino acids (milk, eggs, cheese) has proven therapeutic benefits in UC . 5-Amino salicylic acid reduces fermentative production of hydrogen sulfide by colonic bacteria, and aminoglycosides, which inhibit sulfate-reducing bacteria, are of therapeutic benefit in active UC . Methyl-donating agents are a category of drugs of potential therapeutic use in UC . A correlation between sulfide production and mucosal immune responses in UC needs to be undertaken . Control of sulfidogenesis and sulfide detoxification may be important in the disease process of UC, although whether their roles is in an initiating or promoting capacity has yet to be determined.

Int J Biol Macromol, 1997 Aug, 21(1-2), 115 - 21
Structural studies of CV-70 polysaccharide; Scamparini A et al.; The goal of this paper is the characterization of the chemical structure of the water-soluble polysaccharide, CV-70, produced by bacteria Beijerinckia sp . Beijerinckia sp . is a genus of gram-negative, aerobic bacteria, usually found in sugar cane root . The CV-70 polysaccharide was produced in a fermentation medium containing 5% sucrose as the carbon source, tryptose and salts, at 25 degrees C {1} . The polysaccharide was hydrolyzed with 2 N trifluoroacetic acid at 100 degrees C for 16 h, purified, and analyzed by HPLC . Index of refraction was used for the detection of sugars . For GC-MS analysis, the CV-70 polysaccharide was derivatized through methylation and acetylation . Together with the GC-MS data, periodate oxidation studies were used to determine the possible glucosidic linkages . Carbon-13 NMR studies were carried out with hydrolyzed and silylated samples . Glucose, galactose and fucose were identified as the components in the CV-70 polysaccharide, in a 3:1:3 ratio.

J Dairy Sci, 1997 Aug, 80(8), 1666 - 73
Nutrient fluxes in splanchnic tissue of dairy cows: influence of grass quality; De Visser H et al.; A crossover design was used to investigate the effects of high (450 kg of N/ha) or low (150 kg of N/ha) N fertilization of ryegrass on fermentation and nutrient fluxes in splanchnic tissue of dairy cows fed those grasses . Grass that was fertilized with the high amount of N contained more N and less sugar than did grass that was fertilized with less N . In rumen fluid, the concentration of NH3 N was lower for ryegrass that was fertilized with the low amount of N . The NH3 release by portal-drained viscera and urea synthesis in the liver were higher for cows fed ryegrass that was fertilized with the high amount of N . The concentration of NH3 N in rumen fluid, NH3 N release in portal-drained viscera, urea synthesis in the liver, urea release from the liver, and urea concentrations in milk were highly correlated . The release of acetate and propionate in portal-drained viscera was similar for both grasses and was well correlated with the proportion of volatile fatty acids in rumen fluid . The proportion of butyrate in rumen fluid was closely correlated with the release of butyrate and beta-hydroxybutyrate in portal-drained viscera . Glucose synthesis in the liver indicated gluconeogenesis from amino acids, which corresponded well with urea synthesis in the liver . For the grass fertilized with more N, availability of energy sources for rumen microbes was low, and, therefore, cows did not use the N in that grass efficiently.

J Dairy Res, 1997 Aug, 64(3), 453 - 7
Effect of yogurt and bifidus yogurt fortified with skim milk powder, condensed whey and lactose-hydrolysed condensed whey on serum cholesterol and triacylglycerol levels in rats; Beena A et al.; The possible hypocholesterolaemic properties of milk and fermented milk products have been investigated in groups of albino rats given a basal diet, basal diet plus cholesterol, and basal diet plus cholesterol together with whole milk or standard or bifidus yogurt . The yogurts were fortified with skim milk powder, condensed whey or lactose-hydrolysed condensed whey . After 30 d, triacylglycerols, total cholesterol, HDL-cholesterol and LDL-cholesterol were measured in serum . Whole milk and ordinary yogurt had no hypocholesterolaemic effect, but standard yogurt containing lactose-hydrolysed condensed whey and all bifidus yogurts lowered serum cholesterol . In general, yogurts changed HDL-cholesterol little, but tended to raise triacylglycerols . There was marked lowering of LDL-cholesterol in rats given either type of yogurt fortified with whey proteins . This study has demonstrated in a rat model that bifidus yogurts and yogurts fortified with whey proteins can reduce total and LDL-cholesterol, and suggests that if they have the same effect in human subjects they have potential value in cholesterol-lowering diets.

Microbiology, 1997 Aug, 143 ( Pt 8), 2627 - 37
The Sch9 protein kinase in the yeast Saccharomyces cerevisiae controls cAPK activity and is required for nitrogen activation of the fermentable-growth-medium-induced (FGM) pathway; Crauwels M et al.; In cells of the yeast Saccharomyces cerevisiae, trehalase activation, repression of CTT1 (catalase), SSA3 (Hsp70) and other STRE-controlled genes, feedback inhibition of cAMP synthesis and to some extent induction of ribosomal protein genes is controlled by the Ras-adenylate cyclase pathway and by the fermentable-growth-medium-induced pathway (FGM pathway) . When derepressed cells are shifted from a non-fermentable carbon source to glucose, the Ras-adenylate cyclase pathway is transiently activated while the FGM pathway triggers a more lasting activation of the same targets when the cells become glucose-repressed . Activation of the FGM pathway is not mediated by cAMP but requires catalytic activity of cAMP-dependent protein kinase (cAPK; Tpk1, 2 or 3) . This study shows that elimination of Sch9, a protein kinase with homology to the catalytic subunits of cAPK, affects all target systems in derepressed cells in a way consistent with higher activity of cAPK in vivo . In vitro measurements with trehalase and kemptide as substrates confirmed that elimination of sch9 enhances cAPK activity about two- to threefold, in both the absence and presence of cAMP . In vivo it similarly affected the basal and final level but not the extent of the glucose-induced responses in derepressed cells . The reduction in growth rate caused by deletion of SCH9 is unlikely to be responsible for the increase in cAPK activity since reduction of growth rate generally leads to lower cAPK activity in yeast . On the other hand, deletion of SCH9 abolished the responses of the protein kinase A targets in glucose-repressed cells . Re-addition of nitrogen to cells starved for nitrogen in the presence of glucose failed to trigger activation of trehalase, caused strongly reduced and aberrant repression of CTT1 and SSA3, and failed to induce the upshift in RPL25 expression . From these results three conclusions can be drawn: (1) Sch9 either directly or indirectly reduces the activity of protein kinase A; (2) Sch9 is not required for glucose-induced activation of the Ras-adenylate cyclase pathway; and (3) Sch9 is required for nitrogen-induced activation of the FGM pathway . The latter indicates that Sch9 might be the target of the FGM pathway rather than cAPK itself.

Yeast, 1997 Aug, 13(10), 931 - 43
Surface properties of top- and bottom-fermenting yeast; Dengis PB et al.; The surface physico-chemical properties (hydrophobicity, electrophoretic mobility, chemical composition) of a large set of top- and bottom-fermenting brewing yeasts, harvested in the exponential and stationary growth phases, have been investigated . Bottom- and top-fermenting strains showed different surface properties . Top strains were generally more hydrophobic than bottom strains, due to higher surface protein concentrations . Bottom strains possessed higher surface phosphate concentrations . The different profiles of electrophoretic mobility versus pH for top and bottom strains could be explained by modelling the surface charge according to the surface chemical composition as given by X-ray photoelectron spectroscopy . For bottom strains, the electrical properties were mainly controlled by phosphate, resulting in a low isoelectric point (pH 2 or below) and an electrophoretic mobility that did not become much more negative above pH 4 . For the top strains, they were mainly determined by the balance of protonated amino- and carboxylate groups in proteins, which gave a high isoelectric point (pH 4) and an electrophoretic mobility changing greatly with pH in the range of 2 to 7 . No difference in surface properties was found between flocculating and non-flocculating strains, or between cells from the exponential and stationary growth phases, even for strains where flocculation occurred during the transition from one growth phase to the other.

Yeast, 1997 Aug, 13(10), 903 - 15
Stationary-phase gene expression in Saccharomyces cerevisiae during wine fermentation; Riou C et al.; Genetic engineering of wine yeast strains requires the identification of gene promoters specifically activated under wine processing conditions . In this study, transcriptional activation of specific genes was followed during the time course of wine fermentation by quantifying mRNA levels in a haploid wine strain of Saccharomyces cerevisiae grown on synthetic or natural winery musts . Northern analyses were performed using radioactive probes from 19 genes previously described as being expressed under laboratory growth conditions or on molasses in S . cerevisiae during the stationary phase and/or under nitrogen starvation . Nine genes, including members of the HSP family, showed a transition-phase induction profile . For three of them, mRNA transcripts could be detected until the end of the fermentation . Expression of one of these genes, HSP30, was further studied using a HSP30::lacZ fusion on both multicopy and monocopy expression vectors . The production of beta-galactosidase by recombinant cells was measured during cell growth and fermentation on synthetic and natural winery musts . We showed that the HSP30 promoter can induce high gene expression during late stationary phase and remains active until the end of the wine fermentation process . Similar expression profiles were obtained on five natural winery musts.

Trends Biotechnol, 1997 Aug, 15(8), 315 - 20
Heterologous biopharmaceutical protein expression in Streptomyces; Binnie C et al.; The commercial production of human proteins in recombinant microorganisms for therapeutic use is well established . Systems have been developed to exploit the natural ability of certain bacteria to secrete properly folded, bioactive proteins into the extracellular medium . The streptomycetes are a relatively well-characterized group of nonpathogenic filamentous bacteria that have the capacity to secrete large amounts of protein . In particular, Streptomyces lividans has the ability to secrete human proteins at a commercially viable level, thanks to relatively well-established plasmid-based expression system, a high-biomass fermentation process and a low level of endogenous protease activity.

J Anim Sci, 1997 Aug, 75(8), 2277 - 83
Ruminal fermentation and nutrient digestion in sheep fed hydroxyethylsoyamide; Jenkins TC; Hydroxyethylsoyamide (HESA) was reported previously to protect soybean oil from ruminal biohydrogenation and increase plasma unsaturated fatty acids in sheep . Two digestibility trials with sheep and a rumen in vitro trials were conducted in this study to determine the effects of HESA on ruminal VFA and nutrient digestibility . Trial 1 was a 4 x 4 Latin square with 17-d periods in which four wethers were fed either a control diet (CON) with no added fat, 2.5% soybean oil (SBO), 5% butylsoyamide (BuSA), or 5% HESA . The HESA diet was ground with a mortar and pestle before feeding to disperse fat lumps that formed during diet mixing . Compared with the CON diet, the HESA diet reduced DMI, acetate/ propionate (A/P), and total tract fiber digestibility, but these were not affected by SBO or BuSA . Trial 2 was a 24-h rumen in vitro study showing that total VFA concentration and A/P in cultures were reduced by 10% linoleic acid but not by 10% ethanolamine or 10% HESA . In Trial 3, four wethers were fed the CON and HESA diets in a replicated 2 x 2 Latin square to determine digestibility responses to HESA when grinding was avoided . Fiber digestibilities and A/P were not affected by HESA in Trial 3 . The HESA in this study had variable effects on fiber digestibility that may have been related to physical attributes of the diet, including particle size . Substitution of ethanolamine for butylamine during synthesis of the amide increased fatty acid digestibility but reduced dry matter intake.

J Anim Sci, 1997 Aug, 75(8), 2248 - 55
Considerations for gastrointestinal cannulations in ruminants; Harmon DL et al.; The complexity of ruminant digestion necessitates a greater variety and complexity of experimental methods than with any other species . The fact that dietary ingredients are first subjected to microbial fermentation requires elaborate measures to ascertain nutrients presented for absorption . Numerous approaches have been attempted to obtain representative samples of digesta at sites throughout the gastrointestinal tract . The choices of a researcher before an experiment include animal(s), site(s) for cannula placement, style of cannula, cannula material, and numerous other more subtle factors that may contribute to the success of an experiment . This review compares the advantages and disadvantages of various approaches, cannula types, and cannula materials that should be considered before experiments are conducted.

J Anim Sci, 1997 Aug, 75(8), 2161 - 4
Technical note: pig model for studying nutrient assimilation by the intestine and colon; Kien CL et al.; We have developed a system for chronically catheterizing 10- to 25-d-old pigs that permits stable isotope tracer studies of intestinal or colonic assimilation of nutrients . This model also can be used to ensure constant enteral feeding or to assess the rate of entry into the terminal ileum of carbohydrates, fats, and amino acids . A plastic cannula with a luminal flange can be surgically placed in the stomach for tracer studies of sugar digestion or for controlled infusion of any formula diet . A similar cannula can be placed in the cecum for infusion of tracer and(or) substrates for studies of fermentation . The cannula has been machined so that a washer and nut can be threaded onto it, allowing the entire apparatus to be fixed to the abdominal wall . The distal end protruding above the skin was tapered to fit standard i.v . extension tubing . A carotid arterial catheter was used to sample substrates for isotopic enrichment measurements.

J Gastroenterol, 1997 Aug, 32(4), 453 - 6
Small bowel transit time and colonic fermentation in young and elderly women; Kagaya M et al.; Small bowel transit time (SBTT) in 15 young and 13 elderly women was assessed by measuring breath hydrogen concentrations after they had consumed a solid test meal . The meal consisted of 200 g cooked rice, 50 ml miso (made from fermented soy bean curd) soup, a boiled egg, and 95.5 g of cooked soy beans with mixed vegetables . This meal provided 17 g protein, 14.1 g fat, 92.9 g carbohydrate, 7 g dietary fiber, and 565 kcal total energy . The SBTT, calculated by a mean 3 ppm increase in breath hydrogen, was 191 +/- 14.9 (mean +/- SE) min in the young and 188.1 +/- 16.8 min in the elderly group; the difference was not significant . Breath hydrogen levels, however, were higher in the young than in the elderly group (39.1 +/- 6.3 ppm, vs 22.2 +/- 4.3 ppm, P < 0.05) . There was an initial peak of hydrogen concentration, reached almost immediately after the ingestion of the meal, and then a decline to baseline within 60 min . This initial peak was not as pronounced in the elderly subjects . A second peak, indicating the entry of the test meal into the cecum, was more pronounced in the young than in the elderly group . SBTT did not differ significantly between the two groups, but colonic fermentation was more pronounced in the young, both in the fasting and the postprandial state.

J Biotechnol, 1997 Jul 23, 56(1), 57 - 61
Biotechnological potential of P450 monooxygenases high-level production of bovine cytochrome P450c17 monooxygenase during medium cell density culture of a recombinant yeast, Saccharomyces cerevisiae GRF 18 (YEp-Toku1); Nishihara H et al.; Bovine cytochrome P450c17 monooxygenase was produced in a 30-L fermenter by Saccharomyces cerevisiae GRF18 (YEp-Toku1), harboring the GAL10 promoter, and using conditions of medium cell density culture . Upon addition of D-galactose as an inducer and FeCl3 as a cofactor, cells began to produce the P450 hemoprotein . The yield of this enzyme reached a maximum after 31 h but its formation continued for more than 60 h after induction . The amount of P450c17 produced was 4.7-fold as compared to shake flask experiments.

FEBS Lett, 1997 Jul 7, 411(1), 97 - 101
A novel fluorescent marker for assembled mitochondria ATP synthase of yeast . OSCP subunit fused to green fluorescent protein is assembled into the complex in vivo; Prescott M et al.; We have shown that OSCP, a subunit of yeast mitochondrial ATP synthase, can be incorporated into the intact enzyme as a fusion protein representing OSCP fused at its C-terminus to the green fluorescent protein (GFP) of Aequorea victoria . The relevant fusion OSCP-GFP-h6 additionally contains a hexahistidine tag at the C-terminus . Expression of OSCP-GFP-h6 in yeast cells lacking endogenous OSCP led to the efficient restoration of growth of cells on the non-fermentable substrate, ethanol . Confocal laser scanning microscopy revealed fluorescence due to GFP in mitochondria of cells expressing OSCP-GFP-h6 . Use of immobilised metal ion affinity chromatography enabled the recovery of assembled ATP synthase complexes which contained OSCP-GFP-h6 identified by its mobility on SDS-PAGE and immunoreactivity to anti-OSCP and anti-GFP antibodies . The successful isolation of the assembled multisubunit ATP synthase containing GFP fused to one of the essential subunits of the complex widely expands the potential applications of GFP . In principle, these include the spatial and temporal monitoring of ATP synthase complexes in vivo, and the exploration of interactions involving ATP synthase subunits by fluorescence resonance energy transfer (FRET).

J Ind Microbiol Biotechnol, 1997 Jul, 19(1), 12 - 7
Ethanol production from spent cherry brine; Park H et al.; Spent cherry brine is an acidic byproduct of maraschino cherry processing and typically consists of variable amounts of glucose and fructose of up to 11% fermentable solids, 0.5-1.5% CaCl2, up to 0.4% sulfur dioxide, sorbitol, and lesser amounts of other cherry constituents . Disposal of brine represents a significant cost to processors because of its high biological oxygen demand . As an alternative, brine was tested as a substrate for ethanol production . Initially, the toxic level of sulfur dioxide was reduced by raising brine pH to 8.0 to precipitate calcium sulfite . Because alkalinization was subsequently found to result in a 10-fold reduction in phosphorous, brines were titrated with phosphoric acid to pH 6.0 prior to inoculation with Saccharomyces cerevisiae . All strains of Saccharomyces cerevisiae tested were able to ferment all lots of Ca(OH)2-treated and phosphorous-enriched brines efficiently . One lot of brine containing 10% (w/v) fermentable sugar yielded 4.7% (w/v) ethanol in 4 days.

Appl Microbiol Biotechnol, 1997 Jul, 48(1), 23 - 6
Effect of soybean oil and glucose on sophorose lipid fermentation by Torulopsis bombicola in continuous culture; Kim SY et al.; The effect of soybean oil and glucose on the growth of Torulopsis bombicola and sophorose lipid production in continuous culture was investigated . As the dilution rate in 100 g/l glucose and 100 g/l soybean oil medium was increased, the dry cell weight and sophorose lipid concentration decreased . Sophorose lipid productivity, however, was maximum at a dilution rate of 0.03 h-1 . The cell yield from glucose and the sophorose lipid production from soybean oil were approximately constant regardless of the dilution rate . The specific consumption rate of soybean oil was closely related to the specific production rate of sophorose lipid . These results suggest that soybean oil was used only for sophorose lipid production whereas glucose was used only for cell mass and maintenance . When the soybean oil concentration was varied at fixed dilution rate in 100 g/l glucose medium, a high concentration of soybean oil was found to inhibit sophorose lipid production.

Biotechnol Prog, 1997 Jul-Aug, 13(4), 503 - 5
Reverse micellar extraction of antibiotics from aqueous solutions; Fadnavis NW et al.; Several antibiotics such as erythromycin, oxytetracyclin, benzylpenicillin, and actidione were extracted from aqueous buffers into reverse micellar solution of bis(2-ethylhexyl) sulfosuccinate sodium salt (AOT) in isooctane and recovered with high efficiency under mild conditions . Preliminary experiments with oxytetracycline dissolved in a fermentation broth indicate that the antibiotic can be selectively extracted from the broth and recovered efficiently without serious loss of potency.

Biotechnol Prog, 1997 Jul-Aug, 13(4), 374 - 9
Ubiquitin fusion technology: bioprocessing of peptides; Pilon A et al.; Ubiquitin fusion technology represents an emerging method for economically producing peptides and small proteins in the bacterium Escherichia coli . Our focus is on peptide production where the need for cost-effective, scaleable processes has recently been highlighted by Kelley (1996) . There are two principal features: (1) the expression system consists of a suitable E . coli host strain paired with a plasmid that encodes the ubiquitin fusion and (2) an ubiquitin-specific protease, UCH-L3, which cleaves only C-terminal extensions from ubiquitin . In this work, multigram yields were obtained of four ubiquitin fusions derived from cell paste generated in single 10-L fermentations . All were expressed intracellularly and remained soluble at extremely high levels of expression . Bacterial freeze--thaw lysates contained over 95% pure ubiquitin fusion protein . All four fusions were efficiently cleaved to ubiquitin and the peptide products . In one case, the final yield of peptide was 1.08 g from 3 L of low cell density bacterial culture . The combination of exceptional overexpression of the ubiquitin--peptide fusion proteins and a robust and specific protease are unique advantages contributing to a cost-effective, scaleable, and generic bioprocess for peptide production.

J Pediatr, 1997 Jul, 131(1 Pt 2), S5 - 7
Pioneering recombinant growth hormone manufacturing: pounds produced per mile of height; Cronin MJ; The first efforts to produce recombinant human growth hormone (GH) for clinical use were begun by scientists at Genentech, Inc., almost a generation ago, late in 1979 . The very small market for GH that was predicted at the time led to this manufacturing effort being done as a demonstration project . Among the early issues was whether the Escherichia coli host cell could be routinely produced in a stable manner and be inactivated after the GH production run (as required by Federal guidelines) without the GH being permanently denatured . A 10 L E . coli process was developed, and phase I testing began in early 1981 . The approval of this recombinant GH product by the FDA in 1985 paved the way for many improvements and a sustained production effort in the next decade . The more than 1990 fermentation runs have produced tons of E . coli and more than 130 pounds of GH for both clinical research and the treatment of severely short children.

Dig Dis Sci, 1997 Jul, 42(7), 1354 - 61
Gastroesophageal reflux in achalasia . When is reflux really reflux?
Crookes PF, Corkill S, DeMeester TR.
An abnormal score during 24-hr esophageal pH monitoring in achalasia may be associated either with a slow steady drift to below pH 4, or else multiple sharp dips characteristic of typical gastroesophageal reflux . To test the hypothesis that the former pattern was due to food fermentation and not reflux, samples of chewed bland food (N = 22) were incubated with saliva at 37 degrees C for 24 hr and the pH monitored (in vitro study) . Further, the pH tracings of 20 patients with achalasia before operation and 12 patients after operation were studied (in vivo study) . The pH of chewed food fell to a median of pH 4.0 during incubation and in seven of 22 samples fell to below pH 4 . Preoperatively, four of the five patients with an abnormal pH score showed a slow steady drift, and all of these had evidence of retained food at endoscopy . Postoperatively, three of the six patients with an abnormal pH score had a slow steady drift to below pH 4 . Use of pH 3 as a threshold clearly distinguished true reflux from food fermentation, since the patients with reflux all had an abnormal percentage of time below pH 3.

Biochem J, 1997 Jul 1, 325 ( Pt 1), 101 - 9
Three spinach leaf nitrate reductase-3-hydroxy-3-methylglutaryl-CoA reductase kinases that are required by reversible phosphorylation and/or Ca2+ ions; Douglas P et al.; In spinach (Spinacea oleracea L.) leaf extracts, three protein kinases (PKI, PKII and PKIII) were identified each of which phosphorylated spinach nitrate reductase on serine-543, and inactivated the enzyme in the presence of nitrate reductase inhibitor, 14-3-3 . PKIII was also very active in phosphorylating and inactivating Arabidopsis (Landsberg erecta) 3-hydroxy-3-methylglutaryl-coenzyme A reductase 1 (HMGR1) . PKI and PKII phosphorylated HMGR1 more slowly than PKIII, compared with their relative rates of phosphorylation of nitrate reductase . HMGR1 identical with those that are seen after phosphorylation of serine-577 by the sucrose non-fermenting (SNF1)-like PK, 3-hydroxy-3-methylglutaryl-Co A reductase kinase A (HRK-A), from cauliflower {Dale, Arro, Becerra, Morrice, Boronat, Hardie and Ferrer (1995) Eur . J . Biochem . 233, 506-513} . PKI was Ca2+-dependent when prepared in the absence of protein phosphatase (PP) inhibitors, and largely Ca2+-dependent when prepared in the presence of PP inhibitors (NaF and EGTA) . The Ca2+-independent portion of PKI was inactivated by either PP2A or PP2C, while the Ca2+-dependent portion of PKI became increasingly activated during storage, which we presume was mimicking the effect of an unidentified PP . These findings indicate that PK1 is regulated by two functionally distinct phosphorylations . PKI had a molecular mass of 45 kDa on gel filtration and was active towards substrate peptides that terminated at the +2 residue from the phosphorylation site, whereas PKIII was inactive towards these peptides . PKII was Ca2+-stimulated under all conditions tested . PKIII was Ca2+-indepdented, inactivated by PP2A or PP2C, had a requirement for a hydrophobic residue in the +4 position of peptide substrates, had a molecular mass by gel filtration of approximately 140 kDa, and an antibody against the rye SNF1-related PK (RKIN1) recognized a 58 kDa subunit in fractions containing PKIII . These properties of PKIII are identical with those reported previously for the SNF1-like enzyme, HRK-A . Our results indicate a considerable complexity of kinase cascades mediating the regulation of assimilatory and biosynthetic pathways in response to environmental stimuli in plants.

J Dairy Sci, 1997 Jul, 80(7), 1463 - 81
Creating a system for meeting the fiber requirements of dairy cows; Mertens DR; Current NRC recommendations for dairy cattle provide limited guidance to nutritionists for meeting the fiber and carbohydrate needs of lactating cows . The NRC provide only minimum recommendations for fiber and no accommodation for factors such as physical effectiveness of fiber, interactions with nonfibrous carbohydrates, or animal attributes, which can affect the optimality of dairy rations . To be an improvement, any new system for meeting the fiber requirements of dairy cows must be based on 1) feed characteristics that can be defined and preferably be determined quantitatively using routine laboratory methods and 2) animal requirements that correspond to critical feed characteristics and vary with feeding situation, ration composition, and attributes of the animal . Published data were used to develop coefficients for defining the physical effectiveness or roughage value of feeds and the fiber requirements of dairy cows . Information in this paper is intended to provide practical guidelines for improving current fiber recommendations and to serve as an idealized framework for future research on meeting the fiber requirements of dairy cows . The system is based on NDF as the measure of total chemical fiber in feeds . Adjustments for the effectiveness of NDF in maintaining milk fat production and optimizing ruminal fermentation are based on the particle size and inherent characteristics of NDF that affect chewing activity, ruminal pH, and milk fat production.

J Dairy Sci, 1997 Jul, 80(7), 1447 - 62
Relationship between fermentation acid production in the rumen and the requirement for physically effective fiber; Allen MS; The content of ruminally fermented OM in the diet affects the fiber requirement of dairy cattle . Physically effective fiber is the fraction of feed that stimulates chewing activity . Chewing, in turn, stimulates saliva secretion . Bicarbonate and phosphate buffers in saliva neutralize acids produced by fermentation of OM in the rumen . The balance between the production of fermentation acid and buffer secretion is a major determinant of ruminal pH . Low ruminal pH may decrease DMI, fiber digestibility, and microbial yield and thus decrease milk production and increase feed costs . Diets should be formulated to maintain adequate mean ruminal pH, and variation in ruminal pH should be minimized by feeding management . The fraction of OM that is fermented in the rumen varies greatly among diets . This variation affects the amount of fermentation acids produced and directly affects the amount of physically effective fiber that is required to maintain adequate ruminal pH . Acid production in the rumen is due primarily to fermentation of carbohydrates, which represent over 65% of the DM in diets of dairy cows and have the most variable ruminal degradation across diets . The non-fiber carbohydrate content of the diet is often used as a proxy for ruminal fermentability, but this measure is inadequate . Ruminal fermentation of both nonfiber carbohydrate and fiber is extremely variable, and this variability is not related to the nonfiber carbohydrate content of the diet . The interaction of ruminally fermented carbohydrate and physically effective fiber must be considered when diets for dairy cattle are evaluated and formulated.

J Dairy Sci, 1997 Jul, 80(7), 1366 - 73
Influence of time of feeding a protein meal on ruminal fermentation and forestomach digestion in dairy cows; Robinson PH et al.; Four ruminally and duodenally cannulated dairy cows in midlactation were fed twice daily a mixed diet of alfalfa silage and whole-crop oat silage and a concentrate consisting of primarily barley grain . A high protein supplement was fed at approximately 15% of the estimated dry matter intake of the mixed diet once daily at 0830 h, 0.5 h after the morning meal (day), or at 0030 h, 7.5 h after the evening meal (night) . Cows fed the protein supplement during the night had higher apparent forestomach digestion of organic matter and crude protein . Ruminal concentrations of all volatile fatty acids, except isobutyrate, were higher for cows fed the protein supplement during the night . Although ruminal pH and concentrations of ammonia N did not differ between treatments, time by treatment interactions indicated that the feeding times of the protein supplement influenced diurnal patterns of ruminal fermentation . The flow of nonbacterial nonammonia N at the duodenum, as a proportion of N intake, was lower for cows fed the protein supplement during the night, but production of milk fat was higher . Results were consistent with a mechanism whereby protein fed during the night stimulated ruminal fermentation, particularly during the night, resulting in greater forestomach digestion of organic matter and less escape of dietary protein from the forestomach . Clearly, the different feeding times of this protein supplement changed the nutritional value of the overall diet.

J Dairy Sci, 1997 Jul, 80(7), 1296 - 314
Comparison of mechanistic rumen models on mathematical formulation of extramicrobial and microbial processes; Bannink A et al.; This study investigated the consequences of differences in applied concepts and individual mathematical formulations on steady-state behavior of three important mechanistic rumen models . In the models of Baldwin et al . (2) and Danfaer (6), the formulation of passage rate, nondietary inputs, defined rumen substrate pools, absorption rates, degradation rates, molecular weights, parameterization of VFA production, and physical compartmentalization were sequentially exchanged for the formulation of the model of Dijkstra et al . (9) . Most of these adaptations had a considerable influence on model behavior, indicating large qualitative differences in formulation and sensitivity to concept choice . Because microbial substrate environments were similar after all adaptations, the microbial mechanisms could be compared objectively without being concealed by differences in extramicrobial formulation . None of the microbial functions were altered except for substrate degradation, which gave rise to a similar rate of substrate entrance to soluble rumen pools that are available for microbial utilization . Large differences remained in microbial functions of substrate fermentation, substrate incorporation, and microbial synthesis . Differences in extramicrobial rumen functions and microbial mechanisms had important consequences for simulated nutrient outputs from the rumen, illustrating the necessity for further validation of individual formulations.

Yeast, 1997 Jul, 13(9), 783 - 93
Modulation of glycerol and ethanol yields during alcoholic fermentation in Saccharomyces cerevisiae strains overexpressed or disrupted for GPD1 encoding glycerol 3-phosphate dehydrogenase; Michnick S et al.; The possibility of the diversion of carbon flux from ethanol towards glycerol in Saccharomyces cerevisiae during alcoholic fermentation was investigated . Variations in the glycerol 3-phosphate dehydrogenase (GPDH) level and similar trends for alcohol dehydrogenase (ADH), pyruvate decarboxylase and glycerol-3-phosphatase were found when low and high glycerol-forming wine yeast strains were compared . GPDH is thus a limiting enzyme for glycerol production . Wine yeast strains with modulated GPD1 (encoding one of the two GPDH isoenzymes) expression were constructed and characterized during fermentation on glucose-rich medium . Engineered strains fermented glucose with a strongly modified {glycerol} : {ethanol} ratio . gpd1delta mutants exhibited a 50% decrease in glycerol production and increased ethanol yield . Overexpression of GPD1 on synthetic must (200 g/l glucose) resulted in a substantial increase in glycerol production ( x 4) at the expense of ethanol . Acetaldehyde accumulated through the competitive regeneration of NADH via GPDH . Accumulation of by-products such as pyruvate, acetate, acetoin, 2,3 butane-diol and succinate was observed, with a marked increase in acetoin production.

Eur J Clin Nutr, 1997 Jul, 51(7), 417 - 23
A new look at dietary carbohydrate: chemistry, physiology and health . Paris Carbohydrate Group; Cummings JH et al.; The current view of dietary carbohydrates as simply providing us with energy is outdated . Because of their varied chemistry and physical form the rate and extent to which the different types are digested in and absorbed from the small intestine varies . This in turn leads to affects on satiety, blood glucose and insulin, protein glycosylation, lipids and bile acids . Some carbohydrates reach the colon where they are fermented and affect many aspects of large bowel function, colonocyte and hepatic metabolism . A new framework for classifying and measuring food carbohydrates is needed to allow a greater understanding of the role of individual species in health and to inform the public of their importance . A classification based primarily on molecular size (degree of polymerisation) into sugars, oligosaccharides and polysaccharides, is suggested, with sub-groups identified by the nature of the monosaccharides . Greater knowledge of the chemical and physical properties of carbohydrates allow a more precise relation with physiology and health to be drawn . The Carbohydrate Group met in Paris in December 1995 at the invitation of Gerard Pascal, Director of CNERNA . Financial support for the meeting was provided by CNERNA.

Lab Anim, 1997 Jul, 31(3), 254 - 63
The morphological changes of intestinal mucosa in growing rabbits; Yu B et al.; The study aimed to increase understanding of digestive function from the development of the digestive tract from suckling to maturity in rabbits . The relative weights of the digestive tract (in relation to body weight) in different segments increase linearly during the rapid growth period between 2 and 8 weeks of age, thereafter intestinal weight gain is slower . An underdeveloped mucosal histology was observed in the hindgut of suckling rabbits at 2 weeks compared with 4 weeks of age . From SEM micrographs, the small intestinal mucosal villi look more slender and finger-like in the suckling period, thereafter becoming broader or tongue-like or plate-shaped in mature rabbits . The micrographs showed a compact arrangement in the underdeveloped hindgut mucosa at 2 weeks, but after weaning as hindgut fermentation becomes significant the mucosa increased in surface area.

FEMS Microbiol Lett, 1997 Jul 1, 152(1), 183 - 8
Cloning and sequencing of the cDNA encoding lipase I from Trichosporon fermentans WU-C12; Arai T et al.; A cDNA clone encoding extracellular lipase I (TFL I) from Trichosporon fermentans WU-C12 was isolated and characterized . The TFL I cDNA was isolated from a lambda gt10-based cDNA library using as a probe a 0.8 kb fragment, amplified by PCR with synthetic oligonucleotide corresponding to the partial amino acid sequences of TFL I . The cDNA encodes a protein consisting of 563 amino acids containing a putative signal peptide of 19 amino acids . The deduced amino acid sequence shares 99.5% overall identity with that of lipase II (GCL II) from Geotrichum candidum ATCC 34614, whereas TFL I is a trimer enzyme and GCL II monomer . Southern hybridization with the TFL I cDNA as a probe revealed that WU-C12 contained two different lipase genes.

Int J Syst Bacteriol, 1997 Jul, 47(3), 742 - 6
Mycoplasma crocodyli sp . nov., a new species from crocodiles; Kirchhoff H et al.; Organisms with the typical characteristics of mycoplasmas were isolated from joints and lungs of crocodiles . The results of growth inhibition tests and immunobinding assays showed that the 24 mycoplasma strains isolated were identical and distinct from previously described Mycoplasma, Entomoplasma, Mesoplasma, and Acholeplasma species . These organisms represent a new species, for which the name Mycoplasma crocodyli is proposed . M . crocodyli ferments glucose and maltose, does not produce films and spots, does not hydrolyze arginine, esculin, and urea, reduces tetrazolium chloride, and possesses phosphatase activity . It lyses and adsorbs bovine, ovine, and rabbit erythrocytes . Cholesterol or serum is required for growth . The optimum growth temperature is 37 degrees C . The G + C content of the DNA is 27.6 mol% . This organism causes exudative polyarthritis in crocodiles . The type strain of M . crocodyli is strain MP145 (= ATCC 51981).

Protein Expr Purif, 1997 Jul, 10(2), 214 - 25
Stable expression and purification of a secreted human recombinant prethrombin-2 and its activation to thrombin; Russo G et al.; A human prothrombin cDNA has been engineered to obtain a cDNA coding for a secreted form of human prethrombin-2 . The secreted prethrombin-2 has been produced in a mammalian expression system using DXB11 cells, a mutant strain of CHO cells in which the dihydrofolate reductase gene has been deleted, and an expression vector carrying the dihydrofolate reductase cDNA . Methotrexate-induced gene amplification favored an efficient production of the recombinant protein which accumulated in the culture medium of the DXB11 cells . Growth in suspension of the stable transformants in an airlift fermenter resulted in the production of 25 mg/L recombinant prethrombin-2 . The recombinant protein was purified using single-step affinity chromatography on a recombinant-hirudin column and activated by agarose gel-immobilized ecarin . All purified recombinant prethrombin-2 was activated and the generated recombinant thrombin showed catalytic properties identical to those of plasma-derived alpha-thrombin . This expression system can be used to prepare mutants of prethrombin-2 for structure-function studies investigating thrombin interactions with substrate proteins, inhibitors, and cell membranes.

Metabolism, 1997 Jul, 46(7), 805 - 11
Time of day and glucose tolerance status affect serum short-chain fatty acid concentrations in humans; Wolever TM et al.; Short-chain fatty acids (SCFA) are derived from endogenous (metabolism of fat, carbohydrate, and amino acids) and exogenous (colonic fermentation) sources . To see how time of day and glucose tolerance status influenced serum SCFA concentrations, we determined serum SCFA throughout the day in 22 subjects with impaired glucose tolerance (IGT) and 10 young and eight middle-aged normal controls . On 1 day, insulin sensitivity was assessed as the steady-state plasma glucose (SSPG) level achieved during intravenous infusion of glucose insulin, and somatostatin . On another day, plasma glucose and insulin and serum SCFA levels were measured 12 times over 12 hours with subjects eating a standard diet . SSPG in young controls (5.5 +/- 1.1 mmol/L) was less than in middle-aged controls (9.3 +/- 1.6 mmol/L), which in turn was less than in IGT subjects (13.7 +/- 0.6 mmol/L; P < .01) . Mean plasma glucose in IGT subjects was greater than in normal controls, and mean plasma insulin in IGT subjects was higher than in young controls but similar to the levels in middle-aged controls . Mean 12-hour serum acetate in young controls (143 +/- 13 mumol/L) was greater than in middle-aged controls (104 +/- 11 mumol/L) and IGT subjects (113 +/- 5 mumol/L; P < .05) . Mean 12-hour serum propionate in young controls (3.8 +/- 0.5 mumol/L) was less than in IGT subjects (5.4 +/- 0.3 mumol/L; P < .01), with middle-aged controls being intermediate (4.6 +/- 0.3 mumol/L) . Both young (1.6 +/- 0.3 mumol/L) and middle-aged (1.0 +/- 0.2) controls had lower mean butyrate than IGT subjects (3.1 +/- 0.4 mumol/L; P < .05) . Levels of all three SCFA varied significantly during the day, tending to decrease after breakfast and increase transiently after lunch and dinner . It is concluded that both time of day and glucose tolerance status affect serum SCFA levels in nondiabetic humans . The results suggest that serum acetate is derived primarily from colonic fermentation, serum butyrate primarily from endogenous fatty acid metabolism, and serum propionate from both exogenous and endogenous sources.

J Anim Sci, 1997 Jul, 75(7), 1704 - 7
Comparative ruminal and total tract digestion of a finishing diet containing fresh vs air-dry steam-flaked corn; Zinn RA et al.; Ten Holstein steers (465 +/- 6 kg) with cannulas in the rumen and proximal duodenum were used in a crossover design experiment to evaluate the influence of air-dry vs fresh steam-flaked corn on characteristics of ruminal and total tract digestion . The basal diet contained 77% steam-flaked corn (DM basis) . Air-dry steam-flaked corn (SFC-AD) was obtained from a single batch that had been allowed to air-dry for 5 d before beginning the trial . Fresh steam-flaked corn (SFC-F) was produced daily Monday through Friday . Following production, the SFC-F was placed in air-tight polybags and stored at 4 degrees C until the time of feeding . There was little difference (P > .20) between SFC-AD and SFC-F with respect to site and extent of digestion of OM, starch, and fiber . Moreover, the two treatments did not differ (P > .20) in ruminal degradability of feed N . Apparent total tract N digestion was slightly greater (2.4%, P < .05) for SFC-F than for SFC-AD . Treatments did not affect ruminal pH (P > .20); however, VFA concentration of ruminal fluid tended to be greater (8.3%, P < .10) for SFC-F than for SFC-AD, indicating that the initial rate of fermentation may have been greater with SFC-F . Ruminal molar proportions of acetate were not affected by treatments (P > .20), but ruminal molar proportions of propionate tended to be greater (9.7%, P < .10) and molar proportions of butyrate tended to be less (10.0%, P < .10) for SFC-F than for SFC-AD . We conclude that the characteristics of digestion and the feeding value of steam-flaked corn is not altered by air drying before feeding.

Genetics, 1997 Jul, 146(3), 1131 - 41
Cloning of the Arabidopsis and rice formaldehyde dehydrogenase genes: implications for the origin of plant ADH enzymes; Dolferus R et al.; This article reports the cloning of the genes encoding the Arabidopsis and rice class III ADH enzymes, members of the alcohol dehydrogenase or medium chain reductase/dehydrogenase superfamily of proteins with glutathione-dependent formaldehyde dehydrogenase activity (GSH-FDH) . Both genes contain eight introns in exactly the same positions, and these positions are conserved in plant ethanol-active Adh genes (class P) . These data provide further evidence that plant class P genes have evolved from class III genes by gene duplication and acquisition of new substrate specificities . The position of introns and similarities in the nucleic acid and amino acid sequences of the different classes of ADH enzymes in plants and humans suggest that plant and animal class III enzymes diverged before they duplicated to give rise to plant and animal ethanol-active ADH enzymes . Plant class P ADH enzymes have gained substrate specificities and evolved promoters with different expression properties, in keeping with their metabolic function as part of the alcohol fermentation pathway.

Arthritis Rheum, 1997 Jul, 40(7), 1219 - 28
Mycoplasma infection and rheumatoid arthritis: analysis of their relationship using immunoblotting and an ultrasensitive polymerase chain reaction detection method; Hoffman RW et al.; OBJECTIVE: To examine the relationship between infection with Mycoplasma and the development of rheumatoid arthritis (RA) and juvenile rheumatoid arthritis (JRA) . METHODS: Immunoblotting of patient synovial fluid and sera on detergent-phase membrane protein extracts of various Mycoplasma species was carried out to learn whether patients exhibited serologic evidence of previous exposure to mycoplasmas . Moreover, an ultrasensitive polymerase chain reaction (PCR) method was developed for assessing whether Mycoplasma DNA could be detected in synovial fluid from patients and controls . RESULTS: Immunoblotting provided serologic evidence of previous Mycoplasma exposure in patients and controls . The genus-specific PCR detected known human Mycoplasma species and could reliably detect <5 copies of Mycoplasma hominis, Mycoplasma fermentans, or a molecular mimic control in synovial fluid . Repeat testing revealed no evidence of Mycoplasma DNA in patient synovial samples . CONCLUSION: This study provided serologic evidence suggesting that, while previous exposure to Mycoplasma was common, there was no detectable persistence of Mycoplasma DNA in the synovial fluid or tissue of patients with RA or JRA.

Appl Environ Microbiol, 1997 Jul, 63(7), 2844 - 9
A spontaneous change in the intracellular cyclic AMP level in Aspergillus niger is influenced by the sucrose concentration in the medium and by light; Gradisnik-Grapulin M et al.; A spontaneous rise in intracellular cyclic AMP (cAMP) levels was observed in the early stages of Aspergillus niger growth under conditions yielding large amounts of citric acid . The amount of cAMP formed was found to depend on the initial concentration of sucrose in the medium . Under higher-sucrose conditions, the cAMP peak appeared earlier and was higher, while in lower-sucrose media a flattened peak was observed later in fermentation . Since in media with higher concentrations of sucrose intracellular citric acid starts to accumulate earlier and more rapidly, cAMP synthesis may be triggered by intracellular acidification, which is caused by the dissociation of citric acid . No spontaneous increase in cAMP concentrations could be detected when the cells were grown in continuously illuminated cultures, suggesting that A . niger phosphodiesterase (PDE) is photoregulated . More evidence for the activation of PDE by light was obtained from morphological studies under light and dark conditions in the presence of cAMP or N6,O2'-dibutyryl cAMP, and this idea was additionally supported by experiments in which PDE inhibitors were tested.

Appl Environ Microbiol, 1997 Jul, 63(7), 2821 - 5
Nitrogen availability of grape juice limits killer yeast growth and fermentation activity during mixed-culture fermentation with sensitive commercial yeast strains; Medina K et al.; The competition between selected or commercial killer strains of type K2 and sensitive commercial strains of Saccharomyces cerevisiae was studied under various conditions in sterile grape juice fermentations . The focus of this study was the effect of yeast inoculation levels and the role of assimilable nitrogen nutrition on killer activity . A study of the consumption of free amino nitrogen (FAN) by pure and mixed cultures of killer and sensitive cells showed no differences between the profiles of nitrogen assimilation in all cases, and FAN was practically depleted in the first 2 days of fermentation . The effect of the addition of assimilable nitrogen and the size of inoculum was examined in mixed killer and sensitive strain competitions . Stuck and sluggish wine fermentations were observed to depend on nitrogen availability when the ratio of killer to sensitive cells was low (1:10 to 1:100) . A relationship between the initial assimilable nitrogen content of must and the proportion of killer cells during fermentation was shown . An indirect relationship was found between inoculum size and the percentage of killer cells: a smaller inoculum resulted in a higher proportion of killer cells in grape juice fermentations . In all cases, wines obtained with pure-culture fermentations were preferred to mixed-culture fermentations by sensory analysis . The reasons why killer cells do not finish fermentation under competitive conditions with sensitive cells are discussed.

Appl Environ Microbiol, 1997 Jul, 63(7), 2779 - 84
Glucose metabolism in the yeast Schwanniomyces castellii: role of phosphorylation site I and an alternative respiratory pathway; Zimmer E et al.; Glucose metabolism in a Crabtree-negative yeast, Schwanniomyces castellii, and a cytochrome b-deficient mutant of this strain was investigated in chemostat culture . The wild-type and mutant strains exhibited the same behavior . Oxidative metabolism was observed when the substrate uptake rate (qS) was low . Fermentative metabolites were excreted when the qS value was higher than 0.40 g.g-1.h-1, indicating the occurrence of a respirofermentative metabolism; however, the respiratory quotient (RQ) remained near 1 . When fermentation occurred, the cytochrome pathway was repressed but not the salicylhydroxamic acid (SHAM)-sensitive pathway . The presence of an alternative SHAM-sensitive respiratory pathway and the presence of phosphorylation site I in all metabolic conditions explained the RQ value of 1 and accounted for high biomass yields in oxidative metabolism conditions (0.62 g.g-1 for the wild-type strain and 0.31 g.g-1 for the cytochrome b-deficient mutant strain).

Appl Environ Microbiol, 1997 Jul, 63(7), 2695 - 701
Production of succinic acid through overexpression of NAD(+)-dependent malic enzyme in an Escherichia coli mutant; Stols L et al.; NAD(+)-dependent malic enzyme was cloned from the Escherichia coli genome by PCR based on the published partial sequence of the gene . The enzyme was overexpressed and purified to near homogeneity in two chromatographic steps and was analyzed kinetically in the forward and reverse directions . The Km values determined in the presence of saturating cofactor and manganese ion were 0.26 mM for malate (physiological direction) and 16 mM for pyruvate (reverse direction) . When malic enzyme was induced under appropriate culture conditions in a strain of E . coli that was unable to ferment glucose and accumulated pyruvate, fermentative metabolism of glucose was restored . Succinic acid was the major fermentation product formed . When this fermentation was performed in the presence of hydrogen, the yield of succinic acid increased . The constructed pathway represents an alternative metabolic route for the fermentative production of dicarboxylic acids from renewable feedstocks.

Appl Environ Microbiol, 1997 Jul, 63(7), 2637 - 46
Identification of a laccase gene family in the new lignin-degrading basidiomycete CECT 20197; Mansur M et al.; A new lignin-degrading basidiomycete, strain I-62 (CECT 20197), isolated from decayed wood exhibited both a high dephenolization activity and decolorization capacity when tested on effluents from the sugar cane by-product fermentation industry . It has been classified as a member of the Polyporaceae family . The major ligninolytic activity detected in culture supernatants of basidiomycete I-62 was a phenoloxidase (laccase), in conjunction with small amounts of manganese peroxidase . No lignin peroxidase was detected . Laccase activity was produced in either defined or complete media . Addition of veratryl alcohol as the inducer, in defined medium, enhanced laccase production 10-fold . The use of fructose instead of glucose as a carbon source resulted in a 100-fold increase in laccase specific activity . Native isoelectrofocusing gels stained with guaiacol revealed the presence of at least seven laccase isozymes, with the most intense band being detected at pI 3 . Southern hybridization analysis indicated the presence of a laccase gene family in strain I-62 . Three different genes coding for phenoloxidases, lcc1, lcc2, and lcc3, were cloned and characterized . The high degree of homology between laccases from strain I-62 and laccases from Trametes species suggests a phylogenetic proximity between this new isolated fungus and the genus Trametes.

Am J Clin Nutr, 1997 Jul, 66(1), 62 - 6
Maldigestion and colonic fermentation of wheat bread in humans and the influence of dietary fat; Olesen M et al.; A fraction of wheat bread is malabsorbed in healthy humans . The malabsorbed fraction is bigger than what can be accounted for by in vitro measurements of dietary fibers and resistant starch . To determine whether it is a specific fraction defined by the structure of the starch molecule or a variable amount--which depends on the individual, the amount ingested, and other components of the meal--we performed a dose-response study on wheat bread in healthy human volunteers . Malabsorption was evaluated by using the breath-hydrogen test . Test meals were as follows: 20 g wheat bran mixed in 100 mL water; bread made from 25, 75, 100, 150, and 200 g white wheat flour (WWF); bread made from 0 g WWF and 20 g wheat bran; and bread made from 100 g WWF served with 11 or 26 g butter, corresponding to 20% or 35% of energy from fat in the meals . Three of seven volunteers malabsorbed a fraction of the bread made from 25 g WWF and five of seven a fraction of the bread made from 75 g WWF . All volunteers malabsorbed a fraction of the 100-g WWF bread, Bread made from 180 g WWF and 20 g wheat bran resulted in a breath-hydrogen response of the same magnitude as that from bread made from 200 g WWF alone . The 100-g WWF bread + 11 g butter resulted in a significantly higher breath-hydrogen response than did the bread alone, whereas the 100-g WWF bread + 26 g butter resulted in an average response of the same magnitude as that from bread alone . We conclude that the malabsorbed fraction of wheat bread was dependent on the amount ingested, the composition of the meal, and individual gastrointestinal handling . Fermentation of wheat bran resulted in a very low breath-hydrogen response compared with lactulose or wheat bread . Addition of 11 g butter to the bread seemed to increase the malabsorbed fraction of the starch, an effect that was abolished when the amount of butter was increased to 26 g.

J Nutr, 1997 Jul, 127(7), 1349 - 56
Soluble amylose cornstarch is more digestible than soluble amylopectin potato starch in rats; Zhou X et al.; In liquid enteral formulations, high molecular weight soluble starches may be able to replace glucose and low molecular weight glucose polymers that have high glycemic indices . Male rats were fed either commercial cornstarch, dextrose, modified soluble potato (70-75% amylopectin) starch, or modified soluble amylomaize-7 (70% amylose) starch for 4 wk . Body weights did not differ among the groups . Food consumption was significantly higher in the two modified starch-fed groups than in the two control groups . Commercial cornstarch, dextrose, modified potato starch and modified amylomaize-7 starch were 100 +/- 0, 100 +/- 0, 69.0 +/- 1.0 and 91.5 +/- 0.8% digestible, respectively (n = 9, mean +/- SEM) . The modified potato starch-fed group deposited the least fat, protein and energy . In both modified starch-fed groups, liver weights were significantly greater than in the two control groups . In food-deprived rats, serum free fatty acid concentrations in the modified potato starch-fed group were significantly higher than in the two control groups, and serum glucose concentrations were significantly higher in the two modified starch-fed groups than in the controls . The insulin to glucagon ratios were significantly lower in the modified potato starch-fed and amylomaize-7 starch-fed groups than in the dextrose-fed control group . Serum protein concentrations, measured after food deprivation, were significantly lower in the modified potato starch-fed group than in the other three groups . Gluconeogenesis from fermentation products might account for the high serum glucose concentrations in the two experimental groups . These data indicate that only the modified amylomaize-7 starch may be useful in the development of food products for liquid nutritional supplements because of the high digestibility and the low resultant insulin levels.

FEBS Lett, 1997 Jun 30, 410(2-3), 145 - 9
HIV-1 protein Vpr causes gross mitochondrial dysfunction in the yeast Saccharomyces cerevisiae; Macreadie IG et al.; The biological effects of the HIV-1 accessory protein, Vpr, have been studied in yeast expression systems . In our previous study {1}, employing the pCUP1-vpr copper-inducible expression cassette, Vpr was shown to cause growth arrest and structural defects . In this study yeast constitutively expressing vpr, through elevated copy number and/or elevated transcription levels, displayed no growth arrest in fermentative growth conditions while Vpr was produced at much lower levels than in the inducible expression system . However, such cells were respiratory deficient and unable to utilise ethanol or glycerol as the sole carbon source . They exhibited gross mitochondrial dysfunction displayed in the loss of respiratory chain complex I, II, III, IV and citrate synthase activities . The effects on mitochondria required a C-terminal domain of Vpr that contains a conserved amino acid sequence motif HFRIGCRHSRIG . These results suggest that the widely observed phenomenon of 'Vpr-induced growth arrest' in human cells could be due to mitochondrial dysfunction.

Int J Food Microbiol, 1997 Jun 17, 37(1), 21 - 5
The effects of bakery processing on natural deoxynivalenol contamination; Neira MS et al.; The aim of this study was the evaluation of the influence of the breadmaking process on initial deoxynivalenol (DON) contamination . Samples (92) were taken from four batches of eight different types of products in a low-technology bakery . The final products, as well as the corresponding flours, doughs and fermented doughs were analyzed . Extracts were obtained with acetonitrile:water (84:16), the clean up was made with a multifunctional column and DON was quantified by thin layer chromatography by visual comparison with standards . Confirmation was made by electron capture gas chromatography . The contamination levels in flour samples ranged from 500 micrograms/kg to 2000 micrograms/kg on dry weight basis . The results showed a positive correlation between the initial contamination level and the reduction of DON after fermentation . A significant reduction was observed as a consequence of the breadmaking process.

J Biotechnol, 1997 Jun 13, 55(2), 113 - 24
Biosorption of lead and zinc from solutions using Streptoverticillium cinnamoneum waste biomass; Puranik PR et al.; Mycelial wastes of microbial origin from fermentation industries have been recognized as potential biosorbents for decontamination of waste waters containing heavy metals . Dried, nonliving, granulated biomass of Streptoverticillium cinnamoneum was used for the recovery of lead and zinc from solutions . It was found that pretreatment of the biomass with boiling water for 15 min increased the biosorption of lead and zinc by 52 and 41%, respectively . The optimum pH range for lead uptake was 3.5-4.5 while for zinc it was 5.0-6.0 . The lead and zinc adsorption data when applied to Freundlich and Langmuir isotherm equations showed good correlation (r2 = 0.97) and hence equal conformity to both models . The Scatchard plots indicated clearly that more than one type of binding sites were involved in the adsorption of lead and zinc by the biomass . The maximum loading capacity of S . cinnamoneum biomass was found to be 57.7 mg/g for lead and 21.3 mg/g for zinc with boiling water pretreatment . The loaded metals could be desorbed effectively with dilute hydrochloric acid, nitric acid and 0.1 M EDTA . Treatment with 0.1 M sodium carbonate permitted reuse of the desorbed biomass although the metal loading capacity in the subsequent cycles decreased by 14-37% . The metal biosorbent granules prepared are a value-added product that has the potential for removal/recovery of lead and zinc from dilute solutions on a commercial scale.

J Exp Med, 1997 Jun 2, 185(11), 1951 - 8
Isolation, structure elucidation, and synthesis of a macrophage stimulatory lipopeptide from Mycoplasma fermentans acting at picomolar concentration; Muhlradt PF et al.; Macrophages are typically stimulated by components of microbial cell walls . Surprisingly, cell wall-less mycoplasmas can also very efficiently stimulate macrophages . We showed recently that mycoplasma-derived lipopeptides constitute the active principle . We have now isolated a clone of Mycoplasma fermentans expressing mainly one macrophage-stimulating lipopeptide . This lipopeptide was detergent-extracted and isolated by reversed-phase high-performance liquid chromotography, using nitric oxide release from C3H/HeJ mouse macrophages as bioassay for detection . In contrast to "conventional" bacterial lipoproteins, this lipopeptide had a free NH2 terminus . Amino acid composition, sequence, and the molecular weight of 2,163 . 3 are consistent with the following structure: S-(2, 3-bisacyloxypropyl)cysteine-GNNDESNISFKEK with one mole C16:0, and a further mole of a mixture of C18:0 and C18:1 fatty acid per lipopeptide molecule . The sequence could not be found in either the protein identification resource nor the Swiss Prot data bank . We named this 2-kD lipopeptide, macrophage-activating lipopeptide-2 (MALP-2) . Synthetic dipalmitoyl MALP-2 and mycoplasma-derived MALP-2 were compared with the bioassay . Both lipopeptides showed an identical dose dependency with a half-maximal response at 10(-11) M concentration . MALP-2 may be one of the most potent natural macrophage stimulators besides endotoxin.

Comp Immunol Microbiol Infect Dis, 1997 Jun, 20(3), 271 - 9
Isolation of verotoxigenic Escherichia coli from the Tasmanian environment; Manandhar R et al.; Growing concerns on the emergence of verotoxin producing Escherichia coli (VTEC) in Australia have focused our attention on the possible sources of VTEC within the island state of Tasmania . An analysis of 156 food samples and 194 water samples obtained from various areas revealed evidence of eight possible sources . Six strains, with serotypes Ont:Hnt, O86:H-, O88:H-, O126:H21 and O134:H-, were isolated from water samples . Two VTEC of serotypes Ont:H8, 081:H- were isolated from raw meat samples . The waterborne isolates produced verocytotoxin . VT1, while both foodborne isolates were strong producers of VT2 . Three VTEC isolates produced haemolysins, only one produced enterohaemolysin (EntHly) and the remaining were reported with alpha-haemolysin (alpha-Hly) activity . An important feature in the majority of isolates from water was their lack of ability to ferment lactose these isolates are routinely overlooked in public health laboratories.

Appl Biochem Biotechnol, 1997 Jun, 66(3), 249 - 62
Analysis of biomass cellulose in simultaneous saccharification and fermentation processes; Chung YC et al.; A direct method for determining the cellulose content of biomass residues resulting from simultaneous saccharifiaction and fermentation (SSF) experiment has been developed and evaluated . The method improves on classical cellulose assays by incorporating the enzymatic removal of yeast glucans from the biomass residue prior to acid hydrolysis and subsequent quantification of cellulose-derived glucose . An appropriate cellulase-free, commercially available, yeast-lysing enzyme preparation from Cytophaga was identified . A freeze-drying step was identified as necessary to render the SSF yeast cells susceptible to enzymatic lysis . The method was applied to the analysis of cellulose and yeast-associated glucans in SSF residues from three pretreated feedstocks; hybrid poplar, switchgrass, and cornstover . Cellulose assays employing the lysing-enzyme preparation demonstrated relative errors up to 7.2% when yeast-associated glucans were not removed prior to analysis of SSF residues . Enzymatic lysis of SSF yeast cells may be viewed as a general preparatory procedure to be used prior to subsequent chemical and physical analysis of SSF residues.

Vet Med (Praha), 1997 Jun, 42(6), 165 - 9
Survival of model helminth eggs and larvae (Ascaris suum, Oesophagostomum sp.) in the ensilaging process; Juris P et al.; Ascaris suum nonembryonated eggs remained viable for the most part even after 42 days of ensilaging . At the end of the anaerobic fermentation, mean of damaged eggs was 15.2 +/- 4.02 (min . 11, max . 21), 32.9% . Conversely, the viability of Oesophagostomum sp . nonembryonated eggs and infective L3 larvae was reduced-eggs: mean number 23.6 +/- 3.64 (min . 20 . max . 28) specimens (93.3%), L3 larvae: mean number 24.2 +/- 4.38 (min . 19, max . 28) specimens (96.7%), during the period of study (42 days) . Control group of the same helminth propagative stages, was kept under optimum aerobic conditions . After 42 days of exposition, 9.0 +/- 3.46 (min . 5, max . 11) nonembryonated Ascaris suum eggs (12.9%), 17.33 +/- 2.51 (min . 15, max . 20) Oesophagostomum sp . eggs (36.4%) and 3.66 +/- 1.15 (min . 3, max . 5) Oesophagostomum sp . larvae L3 (6.3%) were damaged on average . Helminth eggs, thick-walled and more resistant to the environment in particular, are able to survive the anaerobic process of ensilaging . To protect animals against parasitic diseases, it is necessary to consider the epidemiological hazard of silages and silage juices, which are potentially contaminated by helminth propagative stages . Silages and silage juices under certain conditions may become harmful to polygastric animals.

J Antibiot (Tokyo), 1997 Jun, 50(6), 490 - 5
UCE6, a new antitumor antibiotic with topoisomerase I-mediated DNA cleavage activity produced by actinomycetes: producing organism, fermentation, isolation and biological activity; Fujii N et al.; A novel antitumor antibiotic, UCE6 (1,3,8,10,11-pentahydroxy-2-methyl-10-(2-oxo-4-hydroxypentyl)na phthacene-5, 12-dione) with topoisomerase I-mediated DNA cleavage activity, was isolated from the culture broth of actinomycetes strain UOE6 . Addition of silicone oil antifoam agent, KS69 (2%), to the fermentation enhanced the production of UCE6 by approximately 3 fold . A total of 1.15 g of UCE6 was recovered as reddish orange crystals from a 100 liter fermentation supplemented with 2% KS69 . UCE6 exhibited growth inhibitory activity against HeLa S3, HCT116 and Lu-65 cells comparable to that of camptothecin.

J Antibiot (Tokyo), 1997 Jun, 50(6), 474 - 8
MR566A and MR566B, new melanin synthesis inhibitors produced by Trichoderma harzianum . II . Physico-chemical properties and structural elucidation; Lee CH et al.; New melanin synthesis inhibitors (MR566A and B) and six related known isocyanocyclopentenes were isolated from the fermentation broth of Trichoderma harzianum, and their structures were elucidated by spectroscopic methods . The structures of novel isocyanides, MR566A (1) and B (2), were elucidated as 1-(3-chloro-1,2-dihydroxy-4-isocyano-4-cyclopenten-1-yl)etha nol, 1-(1,2,3-trihydroxy-3-isocyano-4-cyclopenten-1-yl)ethanol, respectively . The structure of novel oxazole, MR93B (9), was elucidated as 4-{(1Z)-3-hydroxy-2-hydroxymethyl-1-propen-1-yl}oxazole.

J Antibiot (Tokyo), 1997 Jun, 50(6), 469 - 73
MR566A and MR566B, new melanin synthesis inhibitors produced by Trichoderma harzianum . I . Taxonomy, fermentation, isolation and biological activities; Lee CH et al.; New melanin synthesis inhibitors (MR566A and B) and six related known isocyanocyclopentenes were isolated from the fermentation broth of Trichoderma harzianum . The IC50 values of MR566A and B against mushroom tyrosinase were 1.72 and 47 microM, respectively . They inhibited melanin biosynthesis in B16 melanoma cells with MIC values of 0.1 and 2.2 microM, respectively . Also isolated from the same culture extract of T . harzianum was a new oxazole (MR93B), which showed no inhibitory activity against mushroom tyrosinase at a concentration of 1,000 microg/ml.

J Antibiot (Tokyo), 1997 Jun, 50(6), 457 - 68
N-type calcium channel blockers from a marine bacterium, Cytophaga sp . SANK 71996; Morishita T et al.; N-(3-Acyloxyacyl)glycines were isolated as N-type calcium channel blockers from a marine bacterium Cytophaga sp . SANK 71996 . The identification and fermentation of the producing strain and structure characterization of N-(3-acyloxyacyl)glycines by spectral analyses and chemical syntheses are described together with their antagonistic activities.

Appl Microbiol Biotechnol, 1997 Jun, 47(6), 625 - 9
Development of a low-cost fermentation medium for ethanol production from biomass; Kadam KL et al.; Nutrient cost is an important aspect in the fermentation of biomass to ethanol . With a goal of developing a cost-effective fermentation medium, several industrially available nutrient sources were evaluated for their effectiveness in the simultaneous saccharification and fermentation of pretreated poplar with Saccharomyces cerevisiae D5A . These studies showed that a low-cost medium containing 0.3% corn steep liquor and 2.5 mM MgSO4 7H2O was similar in performance to a nutrient-rich medium . Besides its low cost, this alternative medium consists of components that are available on a commercial scale, thereby making it industrially relevant.

Nahrung, 1997 Jun, 41(3), 150 - 4
Influence of white light, near-UV irradiation and other environmental conditions on production of aflatoxin B1 by Aspergillus flavus and ochratoxin A by Aspergillus ochraceus; Aziz NH et al.; The effects of illumination, near-ultraviolet, incubation temperature pH and some minor elements on the growth rate and production of aflatoxin B1 by A . flavus and ochratoxin A by A . ochraceus were investigated . Aflatoxin B1 and ochratoxin A production was considerably higher in the light than in the dark . The greatest aflatoxin B1 and ochratoxin A production was occurred after 11 days of fermentation with light- and dark-grown cultures at 25 degrees C . The mycelial dry weight was also greater in the light than in the dark for both A . flavus and A . ochraceus . Exposure of conidia to near-UV irradiation increased mycelial dry weight and mycotoxins by both fungi more than white light . The greatest aflatoxin B1 and ochratoxin A was at 25 degrees C with UV-grown culture (24 h exposure) producing a mean of 400 and 260 micrograms/50 ml of medium, respectively . The maximum aflatoxin B1 and ochratoxin A yield was obtained at pH 5.5 and with increasing the initial pH to near neutrality, both mycotoxins yield decreased . Iron, copper and zinc were observed to stimulate aflatoxin B1 and ochratoxin A production and enhanced the growth rate of both A . flavus and A . ochraceus.

Mol Microbiol, 1997 Jun, 24(5), 1049 - 60
'Locked-on' and 'locked-off' signal transduction mutations in the periplasmic domain of the Escherichia coli NarQ and NarX sensors affect nitrate- and nitrite-dependent regulation by NarL and NarP; Chiang RC et al.; The Escherichia coli NarX, NarQ, NarL and NarP proteins comprise a two-component regulatory system that controls the expression of many anaerobic electron-transport and fermentation-related genes in response to nitrate and nitrite . Either of the two sensor-transmitter proteins, NarX and NarQ, can activate the response-regulator proteins, NarL and NarP, which in turn are able to bind at their respective DNA regulatory sites to modulate gene expression . NarX contains a conserved 17 amino acid sequence, designated the 'P-box' element, that is essential for nitrate sensing . In this study we characterize narQ mutants that also confer altered nitrate control of NarL-dependent nitrate reductase (narGHJI) and fumarate reductase (frdABCD) gene expression . While some narQ mutations cause the constitutive activation or repression of reporter-gene expression even when the cells are grown in the absence of the nitrate signal (i.e . a 'locked-on' phenotype), other mutations abolish nitrate-dependent control (i.e . a 'locked-off' phenotype) . Interestingly the narQ (A42-->T) and narQ (R50-->Q) mutations along with the analogous narX18 (A46-->T) and narX902 (R54-->E) mutations also confer a 'locked-on' or a 'locked-off' phenotype in response to nitrite, the second environmental signal detected by NarQ and NarX . Furthermore, these narQ and narX mutations also affect NarP-dependent gene regulation of nitrite reductase (nrfABCDEFG) and aeg-46.5 gene expression in response to nitrite . We therefore propose that the NarQ sensor-transmitter protein also detects nitrate and nitrite in the periplasmic space via its periplasmic domain . A signal transduction model, which we previously proposed for NarX, is now extended to NarQ, in which a nitrate- or nitrite-detection event in the periplasmic region of the cell is followed by a signal transduction event through the inner membrane to the cytoplasmic domain of NarQ and NarX proteins to modulate their protein kinase/phosphatase activities.

Can J Cardiol, 1997 Jun, 13(6), 577 - 82
Muscle characteristics in effort angina before and after CABG; Karlsson J et al.; Seven males with effort angina undertook graded ergometer tests and had muscle biopsies taken from their vastus lateralis muscle before, and three and six months after coronary bypass surgery . Muscle fibre composition (percentage of slow twitch fibres), ubiquinone (vitamin Q), and oxidative and fermentative enzyme activities were determined . After six months, muscle ubiquinone and oxidative enzymes were still depressed, indicating sustained muscle trauma . The only peripheral changes were that muscle lactate dehydrogenase and its skeletal muscle-specific subunits and isozymes were increased 35% to 40% (P < 0.001) three to six months postsurgery . Onset of blood lactate accumulation (2.0 mmol/L), symptom-limited ('maximal') exercise and peak blood lactate increased linearly over time (r = 0.52, P < 0.05; r = 0.63, P < 0.01; and r = 0.76, P < 0.001, respectively) . It is suggested that the initial physical performance increase was due to improved circulatory capacity, oxygen delivery and lactate efflux, whereas the increased fermentative capacity ('anaerobic power') first contributed after a lag of three or more months . Whether the muscle histochemical changes reflected a healing process (recovery) is speculative.

J Dairy Sci, 1997 Jun, 80(6), 1179 - 84
Influence of tallow and Aspergillus oryzae fermentation extract in dairy cattle rations; Bertrand JA et al.; Objectives were to determine the effects of adding 3 g/d of Aspergillus oryzae fermentation extract to diets with or without 5.6% added tallow . Twenty-eight Holstein cows (mean = 98 d of lactation) were assigned to a randomized block experiment in a 2 x 2 factorial arrangement of treatments . Treatments were the basal diet 1) without tallow or extract, 2) with extract but no tallow, 3) with tallow but no extract, and 4) with tallow and extract . Milk production, dry matter intake, 3.5% fat corrected milk, digestibility of neutral detergent fiber in the total tract were depressed for cows fed tallow . Addition of fermentation extract did not stimulate fiber digestion or milk production of cows fed diets with or without fat . Addition of extract did not overcome depression of fiber digestibility by cows fed tallow.

J Dairy Sci, 1997 Jun, 80(6), 1150 - 9
Effects of amount and ruminal degradability of protein on nutrient digestibility and production by cows fed tallow; Weigel DJ et al.; Five cows with ruminal cannulas were used in a 5 x 5 Latin square design to determine the effects of fat and amount and ruminal degradability of dietary crude protein (CP) on nutrient digestibility and production of milk and milk components . Treatments were 1) control; 2) 15% CP, soybean meal; 3) 15% CP, by-product proteins; 4) 18% CP, soybean meal; and 5) 18% CP, soybean meal and by-product proteins . Diets 2 through 5 contained 3.5% tallow . Diets consisted of 28% alfalfa haylage, 22% corn silage, and 50% concentrate on a dry matter (DM) basis . Fat did not affect dry matter intake or percentages and yields of fat and CP in milk but increased milk yield 2.5 kg/d . Fat did not affect N fractions in milk but decreased the percentages of short- and medium-chain fatty acids (C6:0 to C16:0) and increased the percentages of long-chain fatty acids (C18:0 and C18:1) in milk fat . Fat did not affect ruminal fermentation characteristics or the percentages of dietary DM, organic matter, CP, acid detergent fiber, neutral detergent fiber, starch, ether extract, and energy that were digested . An increase in dietary CP from 15 to 18% increased dry matter intake 1.7 kg/d; increased intake of gross energy 8 Mcal/d; increased the percentages and quantities of DM, organic matter, CP, and energy digested; increased the quantities of acid detergent fiber and neutral detergent fiber digested; decreased ruminal pH; increased concentrations of total volatile fatty acids; and increased NH3 N in ruminal fluid . However, the difference in dietary CP did not affect milk yield or composition . Replacement of soybean meal in the diet with a mixture of by-product proteins decreased NH3 N in ruminal fluid, tended to decrease concentrations of total volatile fatty acids and increase pH of ruminal fluid, but did not affect milk yield or percentages and yields of milk components.

J Dairy Sci, 1997 Jun, 80(6), 1126 - 35
Effects of cellobiose and monensin on in vitro fermentation of organic acids by mixed ruminal bacteria; Callaway TR et al.; The objective of this study was to determine the effects of cellobiose and monensin on the in vitro fermentation of organic acids (L-aspartate, fumarate, and DL-malate) by mixed ruminal bacteria . Ruminal fluid was collected from a steer fed 36.7 kg of forage and 4.5 kg of concentrate supplement once per day . Ruminal fluid was centrifuged to sediment feed particles and protozoa, and the resulting supernatant, which contained bacteria, was added (33%, vol/vol) to anaerobic media (500 ml) . Incubations (n = 2) were performed in batch culture at 39 degrees C and sampled at 0, 2, 4, 6, 8, 12, and 24 h . Organic acids were added to achieve a final concentration of 7.5 mM . Cellobiose was added to obtain a final concentration of 5 mM, and monensin dissolved in ethanol was included at concentrations of 0 or 5 ppm . Addition of cellobiose to organic acid fermentations increased the rate of organic acid utilization by the mixed bacterial population . Total concentrations of volatile fatty acids were increased by the addition of cellobiose to all fermentations . A lag period (< or = 8 h) occurred in fermentations that were treated with monensin before organic acids were utilized . Total concentrations of volatile fatty acids were increased, and the acetate to propionate ratio was decreased, by monensin treatment . When cellobiose and monensin were added together, propionate production and organic acid utilization were increased . Both cellobiose and monensin affected the in vitro fermentation of organic acids by mixed ruminal bacteria by providing a carbon and energy source and by influencing electron disposal.

Biotechnol Appl Biochem, 1997 Jun, 25 ( Pt 3), 235 - 42
Sources and nature of heterogeneity in recombinant phenol hydroxylase derived from the basidiomycetous soil yeast Trichosporon cutaneum; Waters S et al.; Preparations of the dimeric flavoenzyme phenol hydroxylase derived from Trichosporon cutaneum were found to contain an active tetrameric form when the enzyme was produced in Escherichia coli . The relative content of the tetramer was estimated from scans of silver-stained native PAGE gels and/or size-exclusion chromatography (SEC) . Proportions of up to 22% of the enzyme protein, depending on the growth temperature and the level of added inducer, were observed in independent cultures as well as in purified preparations . No tetramer was ever seen in cell extracts or purified preparations from T . cutaneum . Traces of higher multimers and of possibly deamidated species were also detected in preparations of the recombinant enzyme . The rate of enzyme production seems to be the major factor in promoting formation of the tetramer, whereas the specific growth rate of the fermentor culture appears to be of minor importance . The dimeric and the tetrameric forms were purified using either SEC or ion-exchange chromatography as a final step . The two purified species did not interchange under a variety of conditions, indicating that they are not undergoing rapid equilibria . The FAD of either form, as isolated by SEC, was present to a lower-than-expected extent of 2 equiv/dimer . However, by removing FAD and reconstituting the resulting apoproteins with the cofactor, the FAD content could be increased to 2 equiv . in the dimer and 3 equiv . in the tetramer . Both reconstituted forms exhibited absorption spectra identical with that of phenol hydroxylase from T . cutaneum as well as that of the recombinant enzyme . All spectra were equally perturbed by one equivalent of phenol per enzyme-attached FAD . The ratio of specific activities of the dimeric and the tetrameric forms was, however, lower than expected from the ratio of their FAD contents . The results are compatible with the notion that the tetramer consists of a native phenol hydroxylase dimer associated with a non-native one with a decreased ability to bind FAD, either in one or both of its constituent 'monomers'.

Drug Metab Dispos, 1997 Jun, 25(6), 709 - 15
Microbial models of mammalian metabolism . Biotransformations of HP 749 (besipirdine) using Cunninghamella elegans; Rao GP et al.; HP 749 (besipirdine; Hoechst-Roussel Pharmaceuticals, Inc., Somerville, NJ) and related analogs belonging to the N-(4-pyridinyl)-1H-indol-1-amine class of compounds have shown a potential to mitigate multiple biochemical deficits associated with Alzheimer's disease . HP 749 has demonstrated cholinergic and nonadrenergic activities both in vitro and in vivo, and has potential for the symptomatic treatment of Alzheimer's disease . The three primary metabolites of HP 749 in dogs, rats, and humans result from hydroxylation of the indole ring, N-dealkylation of the parent compound, and sequential hydroxylation and dealkylation . The fungus Cunninghamella elegans (ATCC 36112) converts 25% of HP 749 in a dextrose broth to yield four metabolites, three of which have been reported in mammalian systems . Preparative scale fermentation allowed for the isolation of the major fungal metabolite resulting from hydroxylation of the indole nucleus at position 5 (16%), which was characterized by cochromatographic (TLC and HPLC), 1H-NMR, mass spectral (chemical ionization/MS), and UV comparisons to a synthetic standard . Additional minor fungal metabolites were formed as a result of N-dealkylation (2%), and sequential N-dealkylation and aromatic hydroxylation (2.5%) . C . elegans is being used as a model to help predict and generate the logical mammalian metabolites of related structural analogs of HP 749.

Drug Metab Dispos, 1997 Jun, 25(6), 685 - 92
Stereoselective metabolism of rac-mexiletine by the fungus Cunninghamella echinulata yields the major human metabolites hydroxymethylmexiletine and p-hydroxymexiletine; Freitag DG et al.; rac-Mexiletine is an orally effective class 1b antiarrhythmic agent used to treat ventricular arrhythmias . In vivo experiments have demonstrated . It is predominantly metabolized by the liver with < 10% excreted as unchanged drug . The major mammalian metabolites have been identified as p-hydroxymexiletine (PHM) and hydroxymethylmexiletine (HMM) . The purpose of our study was to determine whether the fungus Cunninghamella echinulata, which possesses a cytochrome P450 system analogous to that found in humans, could be used as a suitable in vitro model for studying the oxidative metabolism of rac-mexiletine . To accomplish this, a high performance liquid chromatographic assay was used that was capable of simultaneously quantifying the enantiomers of mexiletine, HMM, and PHM . Utilizing this procedure, it was demonstrated that C . echinulata stereoselectively converted rac-mexiletine into HMM (4% of added drug) and PHM (32% of added drug) after an incubation period of 50 hr . In addition, metabolite biosynthesis could be optimized by altering fermentation media components . Seven media values and seven pH values were evaluated . It was determined that a medium at pH 7.0 containing yeast extract and sucrose yielded optimal amounts of metabolites.

J Bacteriol, 1997 Jun, 179(12), 4013 - 22
Localized frameshift mutation generates selective, high-frequency phase variation of a surface lipoprotein encoded by a mycoplasma ABC transporter operon; Theiss P et al.; The wall-less mycoplasmas have revealed unusual microbial strategies for adaptive variation of antigenic membrane proteins exposed during their surface colonization of host cells . In particular, high-frequency mutations affecting the expression of selected surface lipoproteins have been increasingly documented for this group of organisms . A novel manifestation of mutational phase variation is shown here to occur in Mycoplasma fermentans, a chronic human infectious agent and possible AIDS-associated pathogen . A putative ABC type transport operon encoding four gene products is identified . The 3' distal gene encoding P78, a known surface-exposed antigen and the proposed substrate-binding lipoprotein of the transporter, is subject to localized hypermutation in a short homopolymeric tract of adenine residues located in the N-terminal coding region of the mature product . High-frequency, reversible insertion/deletion frameshift mutations lead to selective phase variation in P78 expression, whereas the putative nucleotide-binding protein, P63, encoded by the most 5' gene of the operon, is continually expressed . Mutation-based phase variation in specific surface-exposed microbial transporter components may provide an adaptive advantage for immune evasion, while continued expression of other elements of the same transporter may preserve essential metabolic functions and confer alternative substrate specificity . These features could be critical in mycoplasmas, where limitations in both transcriptional regulators and transport systems may prevail . This study also documents that P63 contains an uncharacteristic hydrophobic sequence between predicted nucleotide binding motifs and displays an amphiphilic character in detergent fractionation . Both features are consistent with an evolutionary adaptation favoring integral association of this putative energy-transducing component with the single mycoplasma membrane.

J Bacteriol, 1997 Jun, 179(12), 3972 - 80
Pathways for utilization of carbon reserves in Desulfovibrio gigas under fermentative and respiratory conditions; Fareleira P et al.; The sulfate-reducing bacterium Desulfovibrio gigas accumulates large amounts of polyglucose as an endogenous carbon and energy reserve . In the absence of exogenous substrates, the intracellular polysaccharide was utilized, and energy was conserved in the process (H . Santos, P . Fareleira, A . V . Xavier, L . Chen, M.-Y . Liu, and J . LeGall, Biochem . Biophys . Res . Commun . 195:551-557, 1993) . When an external electron acceptor was not provided, degradation of polyglucose by cell suspensions of D . gigas yielded acetate, glycerol, hydrogen, and ethanol . A detailed investigation of the metabolic pathways involved in the formation of these end products was carried out, based on measurements of the activities of glycolytic enzymes in cell extracts, by either spectrophotometric or nuclear magnetic resonance (NMR) assays . All of the enzyme activities associated with the glycogen cleavage and the Embden-Meyerhof pathway were determined as well as those involved in the formation of glycerol from dihydroxyacetone phosphate (glycerol-3-phosphate dehydrogenase and glycerol phosphatase) and the enzymes that catalyze the reactions leading to the production of ethanol (pyruvate decarboxylase and ethanol dehydrogenase) . The key enzymes of the Entner-Doudoroff pathway were not detected . The methylglyoxal bypass was identified as a second glycolytic branch operating simultaneously with the Embden-Meyerhof pathway . The relative contribution of these two pathways for polyglucose degradation was 2:3 . 13C-labeling experiments with cell extracts using isotopically enriched glucose and 13C-NMR analysis supported the proposed pathways . The information on the metabolic pathways involved in polyglucose catabolism combined with analyses of the end products formed from polyglucose under fermentative conditions provided some insight into the role of NADH in D . gigas . In the presence of electron acceptors, NADH resulting from polyglucose degradation was utilized for the reduction of sulfate, thiosulfate, or nitrite, leading to the formation of acetate as the only carbon end product besides CO2 . Evidence supporting the role of NADH as a source of reducing equivalents for the production of hydrogen is also presented.

J Nutr, 1997 Jun, 127(6), 1055 - 60
Cows' milk fat components as potential anticarcinogenic agents; Parodi PW; The optimum approach to conquering cancer is prevention . Although the human diet contains components which promote cancer, it also contains components with the potential to prevent it . Recent research shows that milk fat contains a number of potential anticarcinogenic components including conjugated linoleic acid, sphingomyelin, butyric acid and ether lipids . Conjugated linoleic acid inhibited proliferation of human malignant melanoma, colorectal, breast and lung cancer cell lines . In animals, it reduced the incidence of chemically induced mouse epidermal tumors, mouse forestomach neoplasia and aberrant crypt foci in the rat colon . In a number of studies, conjugated linoleic acid, at near-physiological concentrations, inhibited mammary tumorigenesis independently of the amount and type of fat in the diet . In vitro studies showed that the milk phospholipid, sphingomyelin, through its biologically active metabolites ceramide and sphingosine, participates in three major antiproliferative pathways influencing oncogenesis, namely, inhibition of cell growth, and induction of differentiation and apoptosis . Mice fed sphingomyelin had fewer colon tumors and aberrant crypt foci than control animals . About one third of all milk triacylglycerols contain one molecule of butyric acid, a potent inhibitor of proliferation and inducer of differentiation and apoptosis in a wide range of neoplastic cell lines . Although butyrate produced by colonic fermentation is considered important for colon cancer protection, an animal study suggests dietary butyrate may inhibit mammary tumorigenesis . The dairy cow also has the ability to extract other potential anticarcinogenic agents such as beta-carotene, beta-ionone and gossypol from its feed and transfer them to milk . Animal studies comparing the tumorigenic potential of milk fat or butter with linoleic acid-rich vegetable oils or margarines are reviewed . They clearly show less tumor development with dairy products.

Biochem J, 1997 Jun 1, 324 ( Pt 2), 627 - 34
Asymmetrical distribution of cardiolipin in yeast inner mitochondrial membrane triggered by carbon catabolite repression; Gallet PF et al.; Transmembrane asymmetry of cardiolipin in yeast was monitored during the switch from fermentative to gluconeogenic growth and the reverse . As soon as cells used ethanol as an electron donor to produce ATP by oxidative phosphorylation, rapid and abundant cardiolipin synthesis was observed on the matrix side of the inner mitochondrial membrane followed by a transverse rearrangement between the two leaflets . The cardiolipin distribution changed from about 20:80 (in/out) to 70:30 (in/out), and after translocation towards the outer leaflet it finally became 37:63 (in/out) . At the same time, cytochrome c oxidase activity remained stable, then increased as a possible result of the topographical rearrangement . During the reverse process from gluconeogenic to fermentative growth, the amount of cardiolipin rapidly decreased by half, its bilayer distribution apparently changing to a monolayer organization before the 20:80 (in/out) asymmetry of repressed cells was re-established . Experimental impairment of cardiolipin topography by antibiotic inhibition of gene expression or in situ dissipation of mitochondrial membrane potential produced data that prove that the amount and transmembrane distribution of the phospholipid are two specific parameters of the mitochondrial inner membrane organization in both fermentative (2.2 fmol/cell and 20:80, in/out) and gluconeogenic (4.2 fmol/cell and 37:63, in/out) growing yeast cells . Finally, the inner mitochondrial membrane topography of cardiolipin appeared to be closely associated with the transmembrane redox potential.

Poult Sci, 1997 Jun, 76(6), 908 - 13
Microbiological quality of cooked chicken breasts containing commercially available shelf-life extenders; Rozum JJ et al.; Experiments were conducted to determine the effect of various shelf-life extenders on the aerobic plate counts (APC) of cooked chicken breast meat stored at refrigeration temperatures . Fresh chicken breast meat obtained from local grocers was injected with either 0.5, 1, 1.5, or 2% sodium lactate; 0.63, 1.25, 1.88, or 2.51 g/kg of a liquid smoke flavoring; 0.33, 0.66, 1, or 1.33% Per/Lac 1901, a fermented whey product; or 0.25, 0.5, 0.75, or 1% Alta 2341, a fermented corn syrup product . The samples were cooked at 85 C dry bulb, 77.8 C wet bulb to an internal temperature of 76.7 C . The cooked chicken breasts were cut into 20-g samples and aseptically placed into Ziploc bags . Initial APC were enumerated following 2-d incubation at 30 C . Additional stored samples (2 C) were subsequently evaluated for APC every week for 5 wk . Only one of the four ingredients, Alta 2341, significantly extended cooked breast meat shelf-life over that of the controls . Using Alta 2341 would be beneficial in extending the refrigerated shelf-life of cooked chicken breast meat up to 5 wk.

Drugs, 1997 Jun, 53(6), 930 - 42
Lactulose, disaccharides and colonic flora . Clinical consequences; Clausen MR et al.; Lactulose is one of the most frequently utilised agents in the treatment of constipation and hepatic encephalopathy because of its efficacy and good safety profile . The key to understanding the possible modes of action by which lactulose achieves its therapeutic effects in these disorders lies in certain pharmacological phenomena: (a) lactulose is a synthetic disaccharide that does not occur naturally; (b) there is no disaccharidase on the microvillus membrane of enterocytes in the human small intestine that hydrolyses lactulose; and (c) lactulose is not absorbed from the small intestine . Thus, the primary site of action is the colon in which lactulose is readily fermented by the colonic bacterial flora with the production of short-chain fatty acids and various gases . The purpose of this review is to focus on some pertinent basic aspects of the clinical pharmacology of lactulose and to discuss the possible mechanisms by which lactulose benefits patients with constipation and hepatic encephalopathy.

Arch Microbiol, 1997 Jun, 167(6), 332 - 42
Environmental and physiological factors affecting the succinate product ratio during carbohydrate fermentation by Actinobacillus sp . 130Z; Van der Werf MJ et al.; Actinobacillus sp . 130Z fermented glucose to the major products succinate, acetate, and formate . Ethanol was formed as a minor fermentation product . Under CO2-limiting conditions, less succinate and more ethanol were formed . The fermentation product ratio remained constant at pH values from 6.0 to 7.4 . More succinate was produced when hydrogen was present in the gas phase . Actinobacillus sp . 130Z grew at the expense of fumarate and l-malate reduction, with hydrogen as an electron donor . Other substrates such as more-reduced carbohydrates (e.g., d-sorbitol) resulted in higher succinate and/or ethanol production . Actinobacillus sp . 130Z contained the key enzymes involved in the Embden-Meyerhof-Parnas and the pentose-phosphate pathways and contained high levels of phosphoenolpyruvate (PEP) carboxykinase, malate dehydrogenase, fumarase, fumarate reductase, pyruvate kinase, pyruvate formate-lyase, phosphotransacetylase, acetate kinase, malic enzyme, and oxaloacetate decarboxylase . The levels of PEP carboxykinase, malate dehydrogenase, and fumarase were significantly higher in Actinobacillus sp . 130Z than in Escherichia coli K-12 and accounted for the differences in succinate production . Key enzymes in end product formation in Actinobacillus sp . 130Z were regulated by the energy substrates.

Ann N Y Acad Sci, 1997 May 23, 819, 142 - 54
Dietary fiber: nutritional lessons for macronutrient substitutes; Behall KM; The wide array of low-fat foods containing soluble fibers have the potential for helping in weight loss or weight control . Consumption of soluble fibers in sufficient quantities has been shown to lower serum lipid concentrations and to improve glycemic response . Some individuals could, eventually, consume a significant portion of their soluble dietary fiber from processed foods containing soluble-fiber fat substitutes . Changes in dietary fiber and starch sources increase the amount of fermentable material reaching the colon . Short-chain fatty acids thus produced are used as an energy source by colonocytes and may inhibit hepatic cholesterol synthesis . However, colonic fermentation can also result in flatulence or diarrhea . In addition, some diets high in soluble fiber have been shown to change intestinal cell morphology in rats . The possible benefits from consumption of a diet high in soluble fiber fat substitutes in serum lipid reduction, glycemic response improvement, and/or weight reduction as well as potential problems in flatulence, mineral absorption, and colonic cell hyperproliferation should be investigated.

Int J Food Microbiol, 1997 May 20, 36(2-3), 241 - 5
Ecology of inoculated and spontaneous fermentations in Rioja (Spain) musts, examined by mitochondrial DNA restriction analysis; Gutierrez AR et al.; Analysis of mitochondrial DNA restriction patterns was used to study the introduction of a selected strain of Saccharomyces cerevisiae for fermentation of non-sterile musts of La Rioja (Spain) . All of the isolates from the inoculated musts showed the restriction pattern of the selected strain . The same technique was used to study the spontaneous fermentation of musts, showing that a few strains were responsible for the fermentations . One of the strains identified from the spontaneous fermentations had been identified in a previous vintage.

Int J Food Microbiol, 1997 May 20, 36(2-3), 235 - 9
A modified agar medium for the screening of proteolytic activity of starter cultures for meat fermentation purposes; Fransen NG et al.; An agar medium, used in the screening of proteolytic activity of dairy-related bacteria, was adapted for assessing the proteolytic capacity of bacteria which were of possible use in meat fermentations . Freeze dried myofibrils, extracted from pork muscle, were incorporated in the medium . The agar plates were inoculated with 20 microl of overnight cultures of different starter strains, and incubated at 30 degrees C for 48 h . After incubation, proteolytic bacteria produced clear zones . Coomassie brilliant blue stain was employed to facilitate the detection of these zones . Proteolytic activity was confirmed in an enzymatic test.

Gene, 1997 May 20, 191(1), 61 - 7
Pyruvate decarboxylase and anaerobic survival in Aspergillus nidulans; Lockington RA et al.; The presence of pyruvate decarboxylase activity has been demonstrated in Aspergillus nidulans, and a gene encoding a pyruvate decarboxylase has been isolated from this organism and physically characterized . The isolation of the pdcA gene in A . nidulans confirms the existence of the alcoholic fermentation pathway in this fungus, despite it being an obligate aerobic organism . Southern analysis showed that it is most probably a single copy gene . Several potential binding sites for a GATAR-binding protein were identified in the sequence just prior to the start point of transcription, and mutant alleles of the GATAR-binding protein-encoding gene, areA, affected pdcA mRNA levels in a manner that suggested that it influences pdcA expression in nitrogen repressing conditions . Other previously reported cases of AREA action are in nitrogen-limiting conditions . Interestingly, the production of ethanol was affected in a similar way by the same areA alleles, suggesting that changes in pdcA mRNA level are reflected in the changes in the level of ethanol production . The experiments presented here confirm that PDC levels are a major determinant of ethanol production under these conditions.

J Chromatogr A, 1997 May 16, 770(1-2), 243 - 52
Use of ion chromatography for monitoring microbial spoilage in the fruit juice industry; Trifiro A et al.; Fruit juices and purees are defined as fermentable, but unfermented, products obtained by mechanical processing of fresh fruits . The presence of undesired metabolites derived from microbial growth can arise from the use of unsuitable fruit or from defects in the production line or subsequent contamination . This involves a loss in the overall quality that cannot be resolved by thermal treatment following the start of fermentation . With these considerations, together with microbiological control, the analysis of different metabolites, which can be considered as microbial growth markers, such as alcohols (i.e . ethanol, etc.), acids (i.e . acetic, fumaric, lactic, etc.) is fundamental in order to achieve a better evaluation of product quality . Enzymatic determination and other single-component analytical techniques are often used for the determination of these metabolites . When the microbial spoilage is not well known, this results in a long and cumbersome procedure . A versatile technique that is capable of determining many metabolites in one analysis could be helpful in improving routine quality control . For this purpose, an ion chromatographic technique, such as ion exclusion, for separation, and diode array spectrophotometry and conductivity, for detection, were evaluated . Both different industrial samples and inoculated samples were analyzed.

Z Naturforsch {C}, 1997 May-Jun, 52(5-6), 359 - 63
Upstream parameters affecting the cell growth and xylitol production by Candida guilliermondii FTI 20037; Silva SS et al.; The effects of yeast extract (0-10 g/l), methanol (0-10% v/v), acetic acid (0-1.0 g/l), furfural (0-0.5 g/l), glucose (0-30 g/l), inoculum age (15-70 h) and product concentration (18-230 g/l) on the xylose-xylitol conversion by Candida guilliermondii FTI 20037 were studied . The xylitol specific productivity increased about 35% at a yeast extract concentration of 1.0 g/l, whereas glucose showed a strong inhibitory effect on the xylitol production and a stimulating effect on the growth of C . guilliermondii . Methanol, acetic acid and furfural under the employed concentrations did not show any positive effect neither on the growth or on the xylose-xylitol conversion by the yeast . The inoculum age showed a strong influence on xylitol formation and the best fermentative parameters were attained using a 40-h inoculum age . A xylitol concentration in the fermentation medium higher than 80 g/l inhibited markedly the xylitol productivity by the yeast C . guilliermondii.

Z Naturforsch {C}, 1997 May-Jun, 52(5-6), 313 - 8
Pulvinatal, a novel bioactive metabolite from the basidiomycete Nidularia pulvinata (Schw.) Fr; Becker U et al.; Pulvinatal (1) was isolated from fermentations of Nidularia pulvinata as an inducer of differentiation of HL-60 promyelocytic leukemia cells . Its structure was elucidated by spectroscopic methods . In addition, N . pulvinata was found to produce 2,4,5-trihydroxy-6-methyl-benzenecarbaldehyde (2) and orsellinic acid (3) . Pulvinatal exhibits weak antifungal and only marginal cytotoxic activities.

Food Chem Toxicol, 1997 May, 35(5), 449 - 57
Inhibition of benzo{a}pyrene-induced mouse forestomach neoplasia and reduction of H2O2 concentration in human polymorphonuclear leucocytes by flavour components of Japanese-style fermented soy sauce; Kataoka S et al.; Previously it was reported that 4-hydroxy-2 (or 5)-ethyl-5 (or 2)-methyl-3(2H)-furanone (HEMF), a characteristic flavour component of Japanese-style fermented soy sauce that exhibits antioxidant activity, inhibits benzo{a}pyrene-induced forestomach neoplasia in mice . The antioxidant and anticarcinogenic activities of other structurally similar soy sauce flavour components are now reported . 4-Hydroxy-5-methyl-3(2H)-furanone (HMF) and 4-hydroxy-2,5-dimethyl-3(2H)-furanone (HDMF) were found to be antioxidants . In particular, HMF and HDMF (as well as HEMF) reduced hydrogen peroxide concentration in human polymorphonuclear leucocytes stimulated by arachidonic acid or 12-O-tetradecanoylphorbol-13-acetate . HMF and HDMF were administered individually in semipurified diet to female ICR mice previously treated with benzo{a}pyrene (1.5 mg/wk, orally for 4 wk) to initiate forestomach neoplasia . The mice were killed at 30 wk of age . Both furanones reduced forestomach neoplasms, with HDMF exhibiting more potency . The data indicate that HDMF and HMF, like HEMF, inhibit carcinogenesis in this system by acting at the post-initiation stage.

Am J Phys Med Rehabil, 1997 May-Jun, 76(3 Suppl), S2 - 8
Primary care for persons with disabilities . An overview of the problem; DeJong G; This article outlines the ongoing health care needs of people with disabilities and how organized health care, particularly primary care, often fails to address these needs in a timely fashion . The article's central argument is that managed care and the ferment present in health care today present enormous opportunities for rehabilitation providers and others to develop creative solutions to address the shortcomings of the present health care system.

J Antibiot (Tokyo), 1997 May, 50(5), 412 - 7
The effect of carbon source, temperature and aeration on the production of ascosteroside, a novel antifungal agent, by Ascotricha amphitricha; Lowe SE et al.; This paper describes the optimization of production of ascosteroside, a novel antifungal agent with an alpha-linked glycoside of a lanosterone-type triterpenoid structure . Glucose, sorbose and inositol were determined to be the best carbon sources for the production of ascosteroside . Temperature affected levels of ascosteroside, with production being highest at 16 degrees C with 1% glucose, and lowest at 32 degrees C . Dissolved oxygen levels were found to be critical in the production of ascosteroside in fermenter cultures . In order for production of ascosteroside to occur in fermenter cultures, the threshold level of dissolved oxygen was found to be above 26%.

Biotechnol Prog, 1997 May-Jun, 13(3), 249 - 57
Enhanced production of human mini-proinsulin in fed-batch cultures at high cell density of Escherichia coli BL21(DE3){pET-3aT2M2}; Shin CS et al.; Synthesis of recombinant protein (human mini-proinsulin) is investigated in fed-batch cultures at high cell concentration of recombinant Escherichia coli BL21(DE3){pET-3aT2M2} . Transcription of the recombinant gene is controlled by a T7 promoter system . The human mini-proinsulin is characterized by a C-chain peptide consisting of only nine amino acids, whereas the C-chain peptide of natural human proinsulin is made up of 35 amino acids . It is expressed in a fusion protein with a small fusion partner (a peptide with 18 amino acids) and finally aggregated into insoluble inclusion bodies in cytoplasm of recombinant E . coli . The fermentative production of this small fusion mini-proinsulin may be of great advantage in enhancing the yield of human insulin . To find an optimum induction strategy, effects of various key cultivation variables on the mini-proinsulin production are examined in high cell density fed-batch cultures . No general correlation is found between preinduction specific growth rate and recombinant protein synthesis, which confers a flexibility in choosing the feeding strategy of preinduction media for achieving the high cell density cultures . A culture temperature below 37 degrees C is unfavorable for recombinant gene expression, and the T7-based expression system is almost completely repressed at 30 degrees C . The nutrient glucose and yeast extract concentration in postinduction feed media is optimized by applying a statistical method for medium optimization, i.e . response surface methodology, and an effective amount of inducer molecule (IPTG) is determined to maximize the specific recombinant protein formation . The mini-proinsulin production in E . coli culture is significantly influenced by the volumetric feed rate of postinduction media, which is shown to be closely related to the plasmid copy number in the recombinant cell . Consequently, in a single-stage fed-batch process, the mini-proinsulin concentration is increased up to 7 g/L, approximately 62 wt % of which corresponds to mature human insulin . A two-stage fed-batch fermentation process, with recombinant cell growth occurring at a constant growth rate and constant cell concentration in a growth fermenter and mini-proinsulin production in an induction fermenter, is designed, and its efficacy in increasing volumetric productivity of mini-proinsulin is demonstrated.

Biotechnol Prog, 1997 May-Jun, 13(3), 232 - 7
Ultrasound stimulates ethanol production during the simultaneous saccharification and fermentation of mixed waste office paper; Wood BE et al.; The commercial production of ethanol from cellulose by simultaneous saccharification and fermentation (SSF) is prevented in part by the high cost of fungal cellulase enzymes . Intermittent exposure of SSF processes to ultrasonic energy under selected conditions (5 FPU of cellulase/g of substrate; 15 min of exposure/240 min cycle during the latter half of SSF) was found to increase ethanol production from mixed waste office paper by approximately 20%, producing 36.6 g/L ethanol after 96 h (70% of the maximum theoretical yield) . Without ultrasound, 10 FPU of cellulase/g of substrate was required to achieve similar results . Continuous exposure of the organism to ultrasonic energy was bacteriostatic and decreased ethanol production but may be useful for the controlling bacterial growth in other processes.

Biotechnol Prog, 1997 May-Jun, 13(3), 222 - 31
Biochemical engineering analysis of critical process factors in the biomass-to-ethanol technology; Philippidis GP et al.; Ethanol from cellulosic biomass is a promising renewable liquid transportation fuel . Applied research in the area of biomass conversion to ethanol in the last 20 years has answered most of the major challenges on the road to commercialization but, as with any new technology, there is still room for performance improvement . A verified mathematical model was used to examine the most critical biochemical engineering aspects of ethanol production in this study . Extensive simulations of the simultaneous saccharification and fermentation (SSF) of cellulose were conducted to identify the effects of operating conditions, pretreatment effectiveness, microorganism parameters, and enzyme characteristics on ethanol production . The results clearly show that the biomass-enzyme interaction plays a dominant role in determining the performance of SSF in batch and continuous operating modes . In particular, the digestibility of the substrate (as a result of pretreatment) and the cellulase enzyme dosage, specific activity, and composition had a profound effect on ethanol yield . This investigation verified the conclusion that R&D emphasis should be placed on developing more effective pretreatment methods and producing cellulase preparations of high specific activity (low cost per enzyme unit) to realize gains from any development of advanced hexose/pentose-fermenting organisms.

Eur J Biochem, 1997 May 1, 245(3), 813 - 8
The absence of the mitochondrial ATP synthase delta subunit promotes a slow growth phenotype of rho- yeast cells by a lack of assembly of the catalytic sector F1; Giraud MF et al.; In the yeast Saccharomyces cerevisiae, inactivation of the gene encoding the delta subunit of the ATP synthase led to a lack of assembly of the catalytic sector . In addition a slow-growth phenotype was observed on fermentable medium . This alteration appears in strains lacking intact mitochondrial DNA and showing a defect in the assembly of the catalytic sector, such as the yeast strain inactivated in the gene encoding the epsilon subunit . In rho mitochondria having an intact F1, the ion movement resulting from the exchange of ADP formed in the organelle and ATP entering the mitochondrial compartment led to a mitochondrial transmembranous potential delta psi that was sensitive to carboxyactractyloside . This ion movement was dramatically decreased in rho mitochondria lacking the delta subunit and thus the F1 sector, whereas a cell devoid of delta subunit and complemented with a plasmid harboring the ATPdelta gene displayed an assembled F1, a normal generation time and a fully restored mitochondrial potential . This result could be linked to the involvement of the membrane potential delta psi which is indispensible for mitochondrial biogenesis.

J Dairy Sci, 1997 May, 80(5), 921 - 8
Effect of nigericin, monensin, and tetronasin on biohydrogenation in continuous flow-through ruminal fermenters; Fellner V et al.; Four ionophores differing in cation selectivity were compared for their effect on microbial fermentation and biohydrogenation by ruminal bacteria in continuous culture . Monensin and nigericin are monovalent antiporters with selective binding affinities for Na+ and K+, respectively . Tetronasin is a divalent antiporter that binds preferentially with Ca2+ or Mg2+ . Valinomycin is a monovalent uniporter and does not exchange K+ for H+ . Steady-state concentrations of 2 micrograms/ml of monensin, nigericin, tetronasin, or valinomycin were maintained by constant infusion into fermenters . Molar percentages of acetate were lower, and those of propionate were higher, in the presence of monensin, nigericin, and tetronasin; all three ionophores also decreased CH4 production . Concentrations of valinomycin as high as 8 micrograms/ml had no effect on volatile fatty acids or CH4 production . Monensin, nigericin, and tetronasin inhibited the rate of biohydrogenation of linoleic acid . Continuous infusion of C18:2n-6 at a steady-state concentration of 314 micrograms/ml into fermenters receiving monensin, nigericin, or tetronasin resulted in lower amounts of stearic acid and higher amounts of oleic acid . Ionophores increased total C18:2 conjugated acids mainly because of an increase in the cis-9, trans-11-C18:2 isomer . If reflected in milk fat, ionophore-induced changes in ruminal lipids could enhance the nutritional qualities of milk.

Plant Mol Biol, 1997 May, 34(1), 31 - 43
Potato SNF1-related protein kinase: molecular cloning, expression analysis and peptide kinase activity measurements; Man AL et al.; A polymerase chain reaction product (PKIN503) was amplified from potato (Solanum tuberosum) cv . Desiree using oligonucleotide primers with sequences which are highly conserved in the plant sucrose non-fermenting 1 (SNF1)-related protein kinase gene family . Southern blot analysis showed the presence of 5-10 SNF1-related genes in the potato genome . PKIN503 was used to screen a tuber cDNA library and a genomic library, and one cDNA and five genomic clones were isolated . The nucleotide sequences of a portion of all five genomic clones were shown to be identical and only one, pgPKIN1, was analysed further . The cDNA was found to be truncated at the 5' end but the cDNA and genomic sequences contained only 15 substitutions, two of which resulted in changes in the derived amino acid sequence . PKIN1 was shown to encode an Mr 57,854 protein with 61-70% sequence similarity with other plant SNF1-related protein kinases . Northern blot analysis revealed some tissue-specific differences in PKIN1 transcript levels, the lowest being detected in leaves and the highest in stolons . However, much greater differences were found in SNF1-related activity, which was measured using a phosphorylation assay with a substrate peptide which has been shown previously to be phosphorylated by plant SNF1-related protein kinases . Activity decreased by almost 80% during development from stolons to mature tubers but it increased about seven-fold during the first seven days of storage after harvesting, before decreasing again . However, activity was highest in mini-tubers, where the levels were 37 times greater than those in mature tubers from a pot-grown plant . Transcript levels in these tissues were approximately equal, clear evidence that SNF1-related protein kinase activity in potato is regulated, in part, post-transcriptionally.

Br J Nutr, 1997 May, 77(5), 757 - 68
The degradability characteristics of fifty-four roughages and roughage neutral-detergent fibres as described by in vitro gas production and their relationship to voluntary feed intake; Blummel M et al.; Fifty-four roughages of known voluntary dry-matter intakes (DMI; range 7.8-35.2 g/kg live weight per d) were examined in vitro in a gas production test . Samples (200 mg) of roughage and roughage neutral-detergent fibre (NDF) respectively were incubated in a mixed suspension of rumen contents for 96 h and the gas volumes recorded after 4, 6, 8, 12, 24, 30, 36, 48, 54, 60 and 96 h . The kinetics of gas production were derived from the volume recordings described by the exponential equation Y = A + B(l-e-ct) where A is the intercept and ideally reflects the fermentation of the soluble and readily available fraction of the feed, B describes the fermentation of the insoluble (but with time fermentable) fraction and c the fractional rate at which B is fermented per h; A + B describes total fermentation . In vitro true dry matter (TD) and NDF degradabilities (NDF-D) after 24 h incubation were also determined . Of the variation in DMI, 75% was accounted for by the in vitro gas production parameters A, B and c in stepwise multiple regressions; 82% of the variation in DMI was explained by the parameters (ANDF + BNDF) and cNDF as obtained from the incubation of roughage NDF . The rate constants (c) were less important than parameters related to the extent of gas production, accounting for only 6.5 (whole roughage) and 4.1% (NDF) of the variation in DMI . There was no statistical advantage in the use of the exponential model describing extent and rate of fermentation over some of the simple gas volume measurements: 75% of the variation in DMI was accounted for by in vitro gas production of whole roughage after 8 h of incubation . On average gas production from NDF measured from 24-96 h accounted for 81% of the variation in DMI . A combination of gas volume measurements after a short period of incubation (4-8 h) with a concomitant determination of NDF-D after many hours (> or = 24 h) can render NDF preparations and long incubation times redundant . A method is suggested to obtain two results for DMI prediction in one single incubation . Of the variation in DMI 80% was accounted for by the incubation of 500 mg whole roughage when incubation was terminated after 24 h and the residual undegraded substrate quantified.

J Appl Microbiol, 1997 May, 82(5), 615 - 8
Glycerol and other fermentation products of apiculate wine yeasts; Romano P et al.; Ninety-six strains of apiculate wine yeasts were studied for their ability to produce glycerol, acetaldehyde, ethyl acetate, sulphur dioxide and hydrogen sulphide in synthetic medium . Hanseniaspora guilliermondii produced smaller quantities of glycerol, acetaldehyde and hydrogen sulphide than Kloeckera apiculata, whereas the production of ethyl acetate and sulphur dioxide was found to be similar . Strains characterized by different capacities and properties were found for both species . The existence of apiculate strains differing in secondary compound production is of technological interest, as these yeasts constitute potential flavour producers . Selected strains of apiculate yeasts might favour an enhanced flavour formation and yield desirable characteristics to the final product.

EMBO J, 1997 May 1, 16(9), 2179 - 87
The two isoenzymes for yeast NAD+-dependent glycerol 3-phosphate dehydrogenase encoded by GPD1 and GPD2 have distinct roles in osmoadaptation and redox regulation; Ansell R et al.; The two homologous genes GPD1 and GPD2 encode the isoenzymes of NAD-dependent glycerol 3-phosphate dehydrogenase in the yeast Saccharomyces cerevisiae . Previous studies showed that GPD1 plays a role in osmoadaptation since its expression is induced by osmotic stress and gpd1 delta mutants are osmosensitive . Here we report that GPD2 has an entirely different physiological role . Expression of GPD2 is not affected by changes in external osmolarity, but is stimulated by anoxic conditions . Mutants lacking GPD2 show poor growth under anaerobic conditions . Mutants deleted for both GPD1 and GPD2 do not produce detectable glycerol, are highly osmosensitive and fail to grow under anoxic conditions . This growth inhibition, which is accompanied by a strong intracellular accumulation of NADH, is relieved by external addition of acetaldehyde, an effective oxidizer of NADH . Thus, glycerol formation is strictly required as a redox sink for excess cytosolic NADH during anaerobic metabolism . The anaerobic induction of GPD2 is independent of the HOG pathway which controls the osmotic induction of GPD1 . Expression of GPD2 is also unaffected by ROX1 and ROX3, encoding putative regulators of hypoxic and stress-controlled gene expression . In addition, GPD2 is induced under aerobic conditions by the addition of bisulfite which causes NADH accumulation by inhibiting the final, reductive step in ethanol fermentation and this induction is reversed by addition of acetaldehyde . We conclude that expression of GPD2 is controlled by a novel, oxygen-independent, signalling pathway which is required to regulate metabolism under anoxic conditions.

J Nat Prod, 1997 May, 60(5), 529 - 32
Bripiodionen, a new inhibitor of human cytomegalovirus protease from Streptomyces sp . WC76599; Shu YZ et al.; Bripiodionen (1), a new natural product, was isolated from Streptomyces sp . WC76599 during the screening of microbial fermentation extracts for their ability to inhibit human cytomegalovirus protease . The structure of 1 was elucidated by spectroscopic methods . Compound 1 displayed inhibitory activity against human cytomegalovirus protease with an IC50 value of 30 microM.

J Nat Prod, 1997 May, 60(5), 525 - 8
Sch 54445: a new polycyclic xanthone with highly potent antifungal activity produced by Actinoplanes sp; Chu M et al.; A novel antifungal agent, Sch 54445, was isolated from the fermentation broth of an Actinoplanes species . Sch 54445 was identified as a polycyclic xanthone related to the albofungin family of compounds on the basis of analyses of spectroscopic data . As a broad-spectrum antifungal agent, Sch 54445 exhibits highly potent activities against various yeasts and dermatophytes with MIC values approximately 0.00038 microgram/mL.

J Nutr, 1997 May, 127(5 Suppl), 819S - 823S
Microbial and animal limitations to fiber digestion and utilization; Varga GA et al.; The ruminal microbial populations attack, degrade and ferment structural carbohydrates in forage cell walls and thereby provide volatile fatty acids and protein to the host animal . Microbial colonization of fiber is quite rapid; however, the rate and extent to which fiber is degraded is determined to a considerable degree by factors such as microbial accessibility to substrate, physical and chemical nature of the forage and kinetics of ruminal digestion . The physical and chemical nature of forages can present a barrier to their complete digestion in the rumen, especially the association of lignin with polysaccharide constituents . Adhesin proteins allow bacteria with cell-bound enzymes to come into intimate contact with their substrates, ensuring that the degradation products are preferentially available . Research on various fibrolytic enzymes and cellulose binding domains may allow for the transfer of novel genetic material to bacteria for enhancing the hydrolysis of plant cell walls . Fungi may also play an important synergistic role in the ruminal digestion of forages by physically disrupting the lignified stem tissue . This allows the ruminal microbes greater access to the plant stem and the digestible portions of the plant . New developments in fiber utilization by ruminants are currently under investigation and include genetic manipulation of ruminal bacteria, chemical and biological treatments of forages, and manipulation of dietary inputs and feeding management.

J Dairy Res, 1997 May, 64(2), 239 - 52
Folate and folate-binding protein content in dairy products; Wigertz K et al.; Recent findings suggest a protective role for folates in the reduction of neural tube defects and possibly also coronary heart disease and cancer . Consequently, an increase in the daily intake of folates is warranted, which emphasizes the need for quantitative as well as qualitative measurements of dietary folates . Milk plays an important part in the food chain in many Western countries today . Several studies suggest that folate-binding proteins might have an impact on folate absorption and therefore their concentrations are also important . The mean concentration of the predominant form of folate, 5-methyltetrahydrofolate (5-CH3THF), was determined using HPLC in thirteen selected dairy products; skim milk powder, two pasteurized milks, UHT milk, two fermented milks, three whey products and four different cheeses . All results were corrected for recovery by spiking the samples with 5-CH3THF . Effects of storage of dairy products on 5-CH3THF concentrations were also investigated; generally small and insignificant fluctuations were found, except for hard cheese, in which 5-CH3THF decreased significantly . There was a significant seasonal variation in the folate concentration of pasteurized milk which peaked in the summer months . The concentrations of folate-binding protein in skim milk powder and pasteurized milk analysed using an enzyme-linked immunosorbent assay were similar . UHT milk and fermented milk, both of which are processed at temperatures > 90 degrees C, contained significantly lower concentrations of folate-binding protein.

J Dairy Res, 1997 May, 64(2), 181 - 95
Effects of dietary calcium soaps of unsaturated fatty acids on digestion, milk composition and physical properties of butter; Enjalbert F et al.; Dairy cows fitted with ruminal, duodenal and ileal cannulas were utilized to investigate the effects of feeding with Ca soaps (CaS) of palm fatty acids (FA) and rapeseed FA . Diets compared were control diet based on maize silage and concentrate, and two diets with 40 g CaS of palm oil FA or rapeseed oil FA/kg diet, replacing part of the concentrates of the control diet . Total digestibilities of dry matter, fibre and fat, and ruminal fermentation were not significantly altered by giving CaS; the extent of ruminal biohydrogenation of total unsaturated C18 FA was significantly reduced by both CaS diets . Apparent intestinal digestibility of FA was not different among diets, although the amount of FA absorbed with the CaS diets was twice that with the control diet . No difference among diets was observed for milk production, or fat and protein contents . Giving CaS diets decreased the proportions of 4:0 to 14:0 FA in milk fat, and increased cis-18:1n-9, compared with control diet . The rapeseed diet lowered the content of 16:0, and increased the contents of 18:0 and trans-18:1n-7 . CaS diets did not result in a marked increase of polyunsaturated FA content in milk fat . Butter from cows fed on the CaS diets contained more liquid fat at 6 and 14 degrees C than butter from the cows fed on the control diet . Incorporating CaS, particularly those from rapeseed, in dairy cows' diets increased C18 FA in milk and improved butter spreadability.

Plant Physiol, 1997 May, 114(1), 119 - 29
Adenosine-5'-phosphate deaminase . A novel herbicide target; Dancer JE et al.; The isolation of carbocyclic coformycin as the herbicidally active component from a fermentation of Saccharothrix species was described previously (B.D . Bush, G.V . Fitchett, D.A . Gates, D . Langley {1993} Phytochemistry 32: 737-739) . Here we report that the primary mode of action of carbocyclic coformycin has been identified as inhibition of the enzyme AMP deaminase (EC 3.5.4.6) following phosphorylation at the 5' hydroxyl on the carbocyclic ring in vivo . When pea (Pisum sativum L . var Onward) seedlings are treated with carbocyclic coformycin, there is a very rapid and dramatic increase in ATP levels, indicating a perturbation in purine metabolism . Investigation of the enzymes of purine metabolism showed a decrease in the extractable activity of AMP deaminase that correlates with a strong, noncovalent association of the phosphorylated natural product with the protein . The 5'-phosphate analog of the carbocyclic coformycin was synthesized and shown to be a potent, tight binding inhibitor of AMP deaminase isolated from pea seedlings . Through the use of a synthetic radiolabeled marker, rapid conversion of carbocyclic coformycin to the 5'-phosphate analog could be demonstrated in vivo . It is proposed that inhibition of AMP deaminase leads to the death of the plant through perturbation of the intracellular ATP pool.

Mol Biol Evol, 1997 May, 14(5), 527 - 36
Detection of convergent and parallel evolution at the amino acid sequence level; Zhang J et al.; Adaptive evolution at the molecular level can be studied by detecting convergent and parallel evolution at the amino acid sequence level . For a set of homologous protein sequences, the ancestral amino acids at all interior nodes of the phylogenetic tree of the proteins can be statistically inferred . The amino acid sites that have experienced convergent or parallel changes on independent evolutionary lineages can then be identified by comparing the amino acids at the beginning and end of each lineage . At present, the efficiency of the methods of ancestral sequence inference in identifying convergent and parallel changes is unknown . More seriously, when we identify convergent or parallel changes, it is unclear whether these changes are attributable to random chance . For these reasons, claims of convergent and parallel evolution at the amino acid sequence level have been disputed . We have conducted computer simulations to assess the efficiencies, of the parsimony and Bayesian methods of ancestral sequence inference in identifying convergent and parallel-change sites . Our results showed that the Bayesian method performs better than the parsimony method in identifying parallel changes, and both methods are inefficient in identifying convergent changes . However, the Bayesian method is recommended for estimating the number of convergent-change sites because it gives a conservative estimate . We have developed statistical tests for examining whether the observed numbers of convergent and parallel changes are due to random chance . As an example, we reanalyzed the stomach lysozyme sequences of foregut fermenters and found that parallel evolution is statistically significant, whereas convergent evolution is not well supported.

J Anim Sci, 1997 May, 75(5), 1393 - 9
Effect of increasing proportion of supplemental nitrogen from urea on intake and utilization of low-quality, tallgrass-prairie forage by beef steers; Koster HH et al.; Five Angus x Hereford steers with ruminal and duodenal fistulas were used in a 5 x 5 Latin square to determine effects of increasing the proportion of urea in supplemental degradable intake protein (DIP) on intake, fermentation, and digestion . Steers had ad libitum access to low-quality, tallgrass-prairie forage (2.4% CP, 76% NDF) . Supplemental DIP (380 g/d) was from sodium caseinate and(or) urea and was balanced with cornstarch to provide a final supplement (approximately 939 g DM/d) that contained 40% CP . The percentages of supplemental DIP from urea were 0, 25, 50, 75, and 100% . Intake of forage OM was not affected (P > or = .30) by urea level . Ruminal and total tract digestibilities of OM and NDF generally responded in a quadratic manner (P < or = .09) to increasing urea, with the lowest values observed at the highest urea level . As a result, digestible OM intake (DOMI) declined (linear, P = .03) with increasing proportions of urea and tended (quadratic, P = .14) to exhibit the largest proportional decline at the highest urea level . The effects of increasing urea on duodenal N flow, microbial efficiency, ruminal contents, and fluid dilution rate were minimal . Ruminal ammonia N and molar percent acetate increased linearly (P < or = .02), whereas most other VFA (except propionate) decreased (P < or = .05) with increasing urea . In conclusion, although forage OM intake was not altered, OM digestion, NDF digestion, and DOMI were lowest when all supplemental DIP was supplied as urea . Changes in fermentation characteristics reflected the change in source of available nitrogen.

J Anim Sci, 1997 May, 75(5), 1380 - 92
Omasal sampling technique for assessing fermentative digestion in the forestomach of dairy cows; Huhtanen P et al.; A procedure allowing digesta sampling from the omasum via a ruminal cannula without repeated entry into the omasum was developed . The sampling system consisted of a device inserted into the omasum via the ruminal cannula, a tube connecting the device to the ruminal cannula, and a single compressor/vacuum pump . Eight cows given ad libitum access to a total mixed diet were used in a crossover design to evaluate the effects of the sampling system on digestive activity, animal performance, and animal behavior . Results indicated that the omasal sampling system has minimal effect on normal digestive and productive functions of high-producing dairy cows . Dry matter intake was reduced (24.0 vs 21.8 kg/d; P < .02) and seemed related more to the sampling procedures than to the device in the omasum . Observations of animal behavior indicated that cows with the sampling device were similar to control cows, although rumination and total chewing times were reduced slightly . The composition of digesta samples was biased toward an over-abundance of the liquid phase, but using a double-marker system to calculate digesta flow resulted in fairly small coefficients of variation for measurements of ruminal digestion variables . This technique may prove useful for partitioning digestion between the fermentative portion of the forestomach and the lower gastrointestinal tract . The omasal sampling procedure requires less surgical intervention than the traditional methods using abomasal or duodenal cannulas as sampling sites to study forestomach digestion and avoids potentially confounding endogenous secretions of the abomasum.

Cell Growth Differ, 1997 May, 8(5), 523 - 32
Short-chain fatty acid-initiated cell cycle arrest and apoptosis of colonic epithelial cells is linked to mitochondrial function; Heerdt BG et al.; Butyrate, a short-chain fatty acid produced during microbial fermentation of fiber, induces growth arrest, differentiation, and apoptosis of colonic epithelial cells in vitro, and our prior work has shown that this induction is tightly linked to mitochondrial activity . Here we demonstrate that 12 h following induction, SW620 human colonic carcinoma cells accumulate simultaneously in G0-G1 and G2-M of the cell cycle . Four h later, during this G0-G1 to G2-M arrest, cells begin to undergo apoptosis . Using a series of unrelated agents that modulate mitochondrial functions, we demonstrate that mitochondrial electron transport and membrane potential are critical in initiation of this butyrate-mediated growth arrest and apoptosis . Colonic tumorigenesis is characterized by abnormalities in proliferation, apoptosis, and mitochondrial activities . Thus, butyrate may reduce risk for colon cancer by inducing a pathway that enhances mitochondrial function, ultimately resulting in initiation of growth arrest and apoptosis of colonic epithelial cells.

Prostate, 1997 May 1, 31(2), 84 - 90
Immunoreactivity of recombinant human glandular kallikrein using monoclonal antibodies raised against prostate-specific antigen; Eerola R et al.; The gene encoding human glandular kallikrein (KLK2) was expressed in Escherichia coli, and the corresponding protein (hK2) was produced by fermentation . The hK2 was characterized by Western blotting and epitope map using monoclonal antibodies (MAbs) specific for another protease, prostate-specific antigen (PSA) with high structural identity (80%) . MAbs that recognized three different epitopes were bound to hK2, representing 7 out of 23 MAbs tested . One epitope was localized to the sequence region around amino acid position 78, which is believed to be glycosylated in hK2 . The affinities of MAbs recognizing hK2 were similar to those for PSA, suggesting that common epitopes seem to contain very conserved structures . The results may help in designing specific diagnostic assays for the assessment of prostate cancer.

Cytometry, 1997 May 1, 28(1), 90 - 5
In vitro detection of Mycoplasma fermentans binding to B-lymphocytes in fresh peripheral blood using flow cytometry; Cheek RF et al.; Previous reports have shown, using fluorescent probes conjugated to the organism, that Mycoplasma fermentans fuses with about 12% of peripheral blood lymphocytes . However, no lymphocyte subset was specified . To elucidate the specific subset of lymphocytes involved, we developed a three-color flow cytometric assay to detect M . fermentans binding to fresh peripheral blood cells . In our assay, two strains of M . fermentans were grown in SP4 glucose broth, mixed with fresh whole blood samples (n > 20), and incubated at 37 degrees C . The blood samples were then stained with a polyclonal antibody to M . fermentans, a monoclonal antibody to B-lymphocytes (CD19), and a monoclonal antibody to T-lymphocytes (CD3) . Using three-color flow cytometry, we obtained data confirming binding of M . fermentans to 10%-15% of peripheral blood lymphocytes with minimal granulocyte or monocyte staining detected . Flow cytometric analysis showed that early binding appears predominantly directed towards B-lymphocytes (86.7 +/- 9.0%), and that this binding could not be blocked by antibodies directed towards common B lymphocyte cell surface antigens . M . fermentans binding to B-lymphocytes occurred within 5 min of in vitro inoculation, reached a maximum within 30-60 min (94-97%), and thereafter plateaued . The binding was concentration dependent over a three log dilution using 10(3) color changing units as standard . Binding to T-lymphocytes was minimal (<5% positive) . B lineage tumor cells or peripheral blood B cells obtained from HIV infected individuals demonstrated reduced binding of M . fermentans . This assay provides a good method to study the cellular interactions of mycoplasma and may help to elucidate pathogenic mechanisms of mycoplasma infections.

Arch Microbiol, 1997 May, 167(5), 289 - 94
Purification and characterization of phosphoenolpyruvate carboxykinase from the anaerobic ruminal bacterium Ruminococcus flavefaciens; Schocke L et al.; Phosphoenolpyruvate (PEP) carboxykinase was purified 42-fold with a 25% yield from cell extracts of Ruminococcus flavefaciens by ammonium sulfate precipitation, preparative isoelectric focusing, and removal of carrier ampholytes by chromatography . The enzyme had a subunit molecular mass of approximately 66.3 kDa (determined by mass spectrometry), but was retained by a filter having a 100-kDa nominal molecular mass cutoff . Optimal activity required activation of the enzyme by Mn2+ and stabilization of the nucleotide substrate by Mg2+ . GDP was a more effective phosphoryl acceptor than ADP, while IDP was not utilized . Under optimal conditions the measured activity in the direction of PEP carboxylation was 17.2 micromol min-1 (mg enzyme)-1 . The apparent Km values for PEP (0.3 mM) and GDP (2.0 mM) were 9- and 14-fold lower than the apparent Km values for the substrates of the back reaction (oxaloacetate and GTP, respectively) . The data are consistent with the involvement of PEP carboxykinase as the primary carboxylation enzyme in the fermentation of cellulose to succinate by this bacterium.

Biochem Biophys Res Commun, 1997 Apr 28, 233(3), 644 - 9
Phosphocholine-containing glycoglycerolipids (GGPL-I and GGPL-III) are species-specific major immunodeterminants of Mycoplasma fermentans; Matsuda K et al.; Mycoplasma fermentans has unique glycoglycerophospholipids (GGPLs: GGPL-I and GGPL-III) . Previously, the structure of these lipids was determined as phosphocholine-6'-alpha-glucopyranosyl-(1'-3)-1, 2-diacyl-glycerol (GGPL-I) and 1"-phosphocholine-2"-aminodihydroxypropane-3"-phospho-6'-alph++ + a- glucopyranosyl-(1'-3)-1, 2-diacyl-glycerol (GGPL-III) . Thin-layer chromatography (TLC) immunostaining showed that the GGPLs were main lipid-antigens of the M . fermentans species . Anti-M . fermentans serum stained mainly the GGPLs, but the other anti-mycoplasma sera (anti-M . arginini, anti-M . hyorhinis, anti-M . pneumonia, anti-M . primatum, and anti-Acholeplasma laidlawii, anti-M . hominis, anti-M . orale, and M . salivarium) stained neither GGPL-I nor GGPL-III . The TLC analysis of glycolipids and phospholipids of various human related mycoplasmas showed clearly that GGPLs are specifically expressed in M . fermentans species . GGPL-I and GGPL-III ranged from 1.6 to 28% and from an undetectable level to 35% of total phospholipids, respectively . Although there was heterogeneity among the amounts of GGPL-I or GGPL-III of M . fermentans strains, all of the M . fermentans strains had GGPL-I and/or GGPL-III . These observations showed that GGPL structures are species-specific immunodeterminants of M . fermentans . The fact that the GGPLs are main phospholipid components of the M . fermentans species means the M . fermentans has a unique choline metabolic pathway . This observation may raise phylogenetic interest.

Biochim Biophys Acta, 1997 Apr 17, 1335(1-2), 40 - 50
Trehalose accumulation in mutants of Saccharomyces cerevisiae deleted in the UDPG-dependent trehalose synthase-phosphatase complex; Ferreira JC et al.; In Saccharomyces cerevisiae, trehalose-6-phosphate synthase converts uridine-5'-diphosphoglucose and glucose 6-phosphate to trehalose 6-phosphate which is dephosphorylated by trehalose 6-phosphatase to trehalose . These two steps take place within a complex consisting of three proteins: trehalose-6-phosphate synthase encoded by the GGS1/TPS1 (= FDP1, = BYP1, = CIF1) gene, trehalose 6-phosphatase encoded by the TPS2 gene and by a third protein encoded by both the TSL1 and TPS3 genes . Using three different methods for trehalose determination, we observed trehalose accumulation in ggs1/tps1delta, tps2delta and tsl1delta mutants, and in the double mutants ggs1/tps1delta/tps2delta and also in ggs1/tps1delta deleted mutants suppressed for growth on glucose . All these mutants harbor MAL genes . Trehalose synthesis in these mutants is probably performed by the adenosine-5'-diphosphoglucose-dependent trehalose synthase, (ADPG-dependent trehalose synthase) which was detected in all strains tested . It is noteworthy that trehalose accumulation in these mutants was detected only in cells grown on weakly repressive carbon sources such as maltose and galactose or during the transition phase from fermentable to non-fermentable growth on glucose . alpha-Glucosidase activity was always present in high amounts . We also describe an adenosine-diphosphoglucosepyrophosphorylase (ADPG-pyrophosphorylase) activity in Saccharomyces cerevisiae which increased concomitantly with the accumulation of trehalose during the transition phase from fermentable to non-fermentable growth in MAL-constitutive (MAL2-8c) strains . The same was observed when MAL-induced (MAL1) strains were compared during growth on glucose and maltose . These results led us to conclude that maltose-induced trehalose accumulation is independent of the UDPG-dependent trehalose-6-phosphate synthase/phosphatase complex; that the ADPG-dependent trehalose synthase is responsible for maltose-induced trehalose accumulation probably by forming a complex with a specific trehalose-6-phosphatase activity and that ADPG synthesis is activated during trehalose accumulation under these conditions.

J Biotechnol, 1997 Apr 4, 54(1), 29 - 42
Production of human interleukin-8 expressed in Escherichia coli: from a laboratory scale for in vitro tests via a technical scale for animal studies to a process scale for a GMP-compatible production; Koltermann A et al.; An Escherichia coli K 12 strain has been constructed for efficient expression of recombinant biologically active human IL-8 (Interleukin-8) . The development of a fermentation and purification process from the laboratory scale (cells from 15 l fermentation broth) to a production scale (cells from 200 l fermentation broth) is described . Material obtained from the laboratory scale was used for initial in vitro studies and for the development of a biological assay . An upscale purification process starting from 80 l fermentation broth resulted in larger amounts of IL-8 needed for preclinical studies . This process includes a fully automated control of the initial affinity chromatography step . Finally, a production process which differed markedly from the small-scale processes was tailor-made for GMP conformity and economic considerations . It consists of a cell disruption step followed by two crossflow diafiltrations with different molecular weight cut offs and filtration rates, one cation exchange chromatography and a final dialysis step . In order to enhance the overall yield of biologically active IL-8, conditions for a resolubilisation of insoluble IL-8 present in the remaining pellet after cell disruption were worked out.

J Nutr Sci Vitaminol (Tokyo), 1997 Apr, 43(2), 249 - 59
Antioxidative mechanism and apoptosis induction by 3-hydroxyanthranilic acid, an antioxidant in Indonesian food Tempeh, in the human hepatoma-derived cell line, HuH-7; Matsuo M et al.; Recently, a new potent antioxidant was isolated from Tempeh (a traditional fermented soybean food in Indonesia) and was identified as 3-hydroxyanthranilic acid (HAA) . This study deals with the antioxidant mechanism of HAA under biological systems and the cytokilling function of HAA to human malignant cells . HAA eliminated free radicals and inhibited the formation of fatty acid hydroperoxide in vitro, suggesting that HAA would serve as an antioxidant in the initial reaction in lipid oxidation systems . Actually, HAA inhibited the formation of the dominant product of membrane lipids, 12-hydroxyeicosatetraenoic acid (12-HETE) at a high concentration, while HAA accelerated 12-HETE formation at a low concentration in mammalian tissue . HAA oxidized glutathione and inhibited superoxide dismutase in vitro . Furthermore, HAA inhibited cell growth and induced apoptosis to HuH-7, a human hepatoma-derived cell line . As long as HAA is taken as a component of Tempeh, and not in large doses as a chemical, it may possibly act as a prooxidant rather than an antioxidant in vivo.

Appl Biochem Biotechnol, 1997 Apr, 66(1), 25 - 30
Synthesis of isopropyl-1-thio-beta-D-glucopyranoside (IPTGlc), an inducer of Aspergillus niger B1 beta-glucosidase production; Birk R et al.; Production of beta-glucosidase in Aspergillus niger B1 is subjected to catabolic repression by glucose . Aspergillus niger B1 grown on bran as a carbon source secreted beta-glucosidase . The maximum level of the enzyme was reached after 7 d of fermentation . Addition of 1% glucose to the medium suppressed beta-glucosidase production to undetectable levels . In this study, the organic synthesis of a potential inducer of beta-glucosidase production by A . niger B1's reported . Isopropyl-1-thio-beta-D-glucopyranoside (IPTGlc) was synthesized using a two-step organic synthesis protocol . The H-NMR data agreed with those reported previously for the galactoside analog . When IPTGlc was added 24 h after inoculation at a final concentration of 0.4 mM, similar levels of beta-glucosidase were reached 3 to 4 d earlier as compared to fermentation without IPTGlc induction . In practice, this may translate to a more efficient method of producing beta-glucosidase from this fungus.

Appl Biochem Biotechnol, 1997 Apr, 66(1), 1 - 23
Hybrid process for the conversion of lignocellulosic materials; Lee KC et al.; Because of the recalcitrant nature of lignocellulosic materials, it is important to pretreat the biomass in order to obtain a suitable material for the bioconversion . In this study, two different types of pretreatments were performed . The first experiment used a 2-gal Parr reactor operated at 140, 150, 160, and 170 degrees C with sulfuric acid concentrations varying from 0.5 to 2% . A second pretreatment was performed with a two-stage low-temperature process . The first-stage pretreatment was performed at 100 or 120 degrees C with sulfuric acid concentrations of 0.5, 2, and 5% followed by a second-stage pretreatment at 120 degrees C with 2% acid concentration . The best residues for enzymatic hydrolysis and simultaneous saccharification and fermentations (SSF) came from the higher temperature pretreatment with the Parr reactor . However, a large portion of the xylose fraction was degraded to furfural and glucose was degraded to HMF . On the contrary, the two-stage low temperature pretreatment resulted in a very low percentage of xylose degradation, and no glucose degradation . The residues from this two-stage pretreatment performed satisfactorily toward the production of ethanol by SSFs . This study discusses the results obtained from these experiments.

J Antibiot (Tokyo), 1997 Apr, 50(4), 325 - 9
Pterulinic acid and pterulone, two novel inhibitors of NADH:ubiquinone oxidoreductase (complex I) produced by a Pterula species . I . Production, isolation and biological activities; Engler M et al.; Pterulinic acid (1) and pterulone (2), two novel halogenated antibiotics, were isolated from fermentations of Pterula sp . 82168 . Both compounds exhibited significant antifungal and weak or no cytotoxic activities . 1 and 2 are effective inhibitors of eucaryotic respiration . The target of the antibiotics resides within the mitochondrial NADH:ubiquinone oxidoreductase (complex I).

J Antibiot (Tokyo), 1997 Apr, 50(4), 304 - 8
PF1092A, B and C, new nonsteroidal progesterone receptor ligands produced by Penicillium oblatum . I . Taxonomy of producing strain, fermentation, isolation and biological activities; Tabata Y et al.; Three new nonsteroidal progesterone receptor ligands, PF1092A, B and C, have been isolated from Penicillium oblatum . They were purified from the solid cultures of rice media using ethyl acetate extraction, silica gel and Sephadex LH-20 column chromatographies, and crystallization . All three ligands competitively inhibited {3H}-progesterone binding to porcine uteri cytosol preparations with IC50 of 3.0 x 10 nM (PF1092A), 2.2 x 10(2) nM (PF1092B) and 2.2 x 10(3) nM (PF1092C).

J Antibiot (Tokyo), 1997 Apr, 50(4), 297 - 303
A new anthracycline antibiotic, IT-62-B, converts the morphology of ras-transformed cells back to normal: taxonomy, fermentation, isolation, structure elucidation and biological characterization; Kawauchi T et al.; A new antibiotic, IT-62-B was isolated from the culture broth of Streptomyces sp . IT-62 by extraction with acetone and then with ethyl acetate, followed by conventional column chromatography using silica gel, Sephadex LH-20 and silica ODS . Its structure (C39H47NO15, MW 769) was determined by 1H, 13C NMR, MS, IR and UV spectrometric techniques to be a new member of the baumycin-group anthracyclines . It showed moderate activity against Gram-positive bacteria and had antitumor activity against various tumor cell lines . Further, antibiotic IT-62-B converted the morphology of ras-transformed NIH3T3 cells and T-cells back to normal at concentrations inhibiting cell growth by 30% or more.

Anticancer Drugs, 1997 Apr, 8 Suppl 1, S39 - 42
Mistletoe extract-induced effects on immunocompetent cells: in vitro studies; Stein GM et al.; Cytotoxic as well as immunomodulatory effects of mistletoe extracts and their components have been described and seem to depend upon the host tree, the manufacturing process and the composition of the different components present in the extracts . In vitro studies showed that a fermented mistletoe extract derived from Viscum album L . grown on pine trees was less cytotoxic to peripheral blood mononuclear cells (PBMC) than other preparations . This finding could be related to its very low content of mistletoe lectins . Furthermore, this extract stimulated PBMC from healthy and especially allergic donors who had never received any mistletoe treatment . By analysing these in vitro reactions, an involvement of CD4+ T helper cells and CD14+ monocytes/macrophages was observed, suggesting an interaction of the specific and nonspecific immune system . In the supernatants of stimulated PBMC from healthy individuals, type-1 (interferon-gamma and interleukin-2) and type-2 (interleukin-4 and interleukin-5) associated cytokines were detected in about 20% . In patients with colorectal tumours, however, reduced frequency, suggesting a functional impairment of certain immunocompetent cells in these patients . These studies may help to evaluate properties of the natural and the specific immune system.

J Ind Microbiol Biotechnol, 1997 Apr, 18(4), 260 - 6
Process optimization for large-scale production of TGF-alpha-PE40 in recombinant Escherichia coli: effect of medium composition and induction timing on protein expression; Lee C et al.; The effects of medium composition and induction timing on expression of a chimeric fusion protein TGF-alpha-PE40 (TP-40) in Escherichia coli strain RR1 were examined using a complex medium at several fermentor scales . Two distinctive phases in E . coli catabolism were identified during fermentation based on preferential utilization between protein hydrolysate and glycerol . Maximum specific and volumetric productivities were achieved by inducing the culture when the cells were switching substrate utilization from protein hydrolysate to glycerol . By increasing the yeast extract concentration in the production medium, initiation of the catabolic switch was delayed until high cell mass was achieved . The final titer of TP-40 at the 15-L fermentation scale was doubled from 400 mg L-1 to 850 mg L-1 by increasing the yeast extract concentration from 1% to 4% (w/v) and delaying the time of induction . This fermentation process was rapidly scaled up in 180-L and 800-L fermentors, achieving TP-40 titers of 740 and 950 mg L-1, respectively.

Appl Biochem Biotechnol, 1997 Spring, 63-65, 221 - 41
Fermentation of biomass-derived glucuronic acid by pet expressing recombinants of E . coli B; Lawford HG et al.; The economics of large-scale production of fuel ethanol from biomass and wastes requires the efficient utilization of all the sugars derived from the hydrolysis of the heteropolymeric hemicellulose component of lignocellulosic feedstocks . Glucuronic and 4-O-methyl-glucuronic acids are major side chains in xylans of the grasses and hardwoods that have been targeted as potential feedstocks for the production of cellulosic ethanol . The amount of these acids is similar to that of arabinose, which is now being viewed as another potential substrate in the production of biomass-derived ethanol . This study compared the end-product distribution associated with the fermentation of D-glucose (Glc) and D-glucuronic acid (GlcUA) (as sole carbon and energy sources) by Escherichia coli B (ATCC 11303) and two different ethanologenic recombinants--a strain in which pet expression was via a multicopy plasmid (pLOI297) and a chromosomally integrated construct, strain KO11 . pH-stat batch fermentations were conducted using a modified LB medium with 2% (w/v) Glc or GlcUA with the set-point for pH control at either 6.3 or 7.0 . The nontransformed host culture produced only lactic acid from glucose, but fermentation of GlcUA yielded a mixture of ethanol, acetic, and lactic acids, with acetic acid being the predominant end-product . The ethanol yield associated with GlcUA fermentation by both recombinants was similar, but acetic acid was a significant by-product . Increasing the pH from 6.3 to 7.0 increased the rate of glucuronate fermentation, but it also decreased the ethanol mass yield from 0.22 to 0.19 g/g primarily because of an increase in acetic acid production . In all fermentations there was good closure of the carbon mass balance, the exception being the recombinant bearing plasmid pLOI297 that produced an unidentified product from GlcUA . The metabolism of GlcUA by this metabolically engineered construct remains unresolved . The results offered insights into metabolic fluxes and the regulation of pyruvate catabolism in the wild-type and engineered strains . End-product distribution for metabolism of glucuronic acid by the nontransformed, wild-type E . coli B and recombinant strain KO11 suggests that the enzyme pyruvate-formate lyase is not solely responsible for the production of acetylCoA from pyruvate and that derepressed pyruvate dehydrogenase may play a significant role in the metabolism of GlcUA.

Appl Biochem Biotechnol, 1997 Spring, 63-65, 153 - 8
Expression of Ascaris suum malic enzyme in a mutant Escherichia coli allows production of succinic acid from glucose; Stols L et al.; The malic enzyme gene of Ascaris suum, was cloned into the vector pTRC99a in two forms encoding alternative amino-termini . The resulting plasmids, pMEA1 and pMEA2, were introduced into Escherichia coli NZN111, a strain that is unable to grow fermentatively because of inactivation of the genes encoding pyruvate dissimilation . Induction of pMEA1, which encodes the native animoterminus, gave better overexpression of malic enzyme, approx 12-fold compared to uninduced cells . Under the appropriate culture conditions, expression of malic enzyme allowed the fermentative dissimilation of glucose by NZN111 . The major fermentation product formed in induced cultures was succinic acid.

Appl Biochem Biotechnol, 1997 Spring, 63-65, 97 - 108
Regulation of phosphotransferases in glucose- and xylose-fermenting yeasts; Yang VW et al.; This research examined the titers of hexokinase (HK), phosphofructokinase (PFK), and xylulokinase (XUK) in Saccharomyces cerevisiae and two xylose fermenting yeasts, Pachysolen tannophilus and Candida shehatae, following shifts in carbon source and aeration . Xylose-grown C . shehatae, glucose-grown P . tannophilus, and glucose-grown S . cerevisiae, had the highest specific activities of XUK, HK, and PFK, respectively . XUK was induced by xylose to moderate levels in both P . tannophilus and C . shehatae, but was present only in trace levels in S . cerevisiae . HK activities in P . tannophilus were two to three fold higher when cells were grown on glucose than when grown on xylose, but HK levels were less inducible in C . shehatae . The PFK activities in S . cerevisiae were 1.5 to 2 times higher than in the two xylose-fermenting yeasts . Transfer from glucose to xylose rapidly inactivated HK in P . tannophilus, and transfer from xylose to glucose inactivated XUK in C . shehatae . The patterns of induction and inactivation indicate that the basic regulatory mechanisms differ in the two xylose fermenting yeasts.

Appl Microbiol Biotechnol, 1997 Apr, 47(4), 398 - 404
Isolation of isoflavones from soy-based fermentations of the erythromycin-producing bacterium Saccharopolyspora erythraea; Hessler PE et al.; A search for an abundant and economical source of isoflavones, particularly genistein, led to the discovery that the erythromycin-producing organism Saccharopolyspora erythraea also produces this promising new cancer-prevention agent . Erythromycin fermentation is a large-scale, soybean-based process used world-wide for the commercial production of this medically important antibiotic . Results from this study indicate that genistein (the glucoside form of genistein), which is added to the fermentation in the soybean media, was converted to genistein through the action of a beta-glucosidase produced by the organism . Genistein was co-extracted with erythromycin from the fermentation broth, then separated from erythromycin during the second step of the purification process for the production of erythromycin.

Br J Nutr, 1997 Apr, 77 Suppl 1, S121 - 8
Sugar, alternative sweeteners and meal frequency in relation to caries prevention: new perspectives; Kandelman D; In the last 20 years, mainly due to optimum fluoride exposure, and practice of good oral hygiene procedures, an important reduction in caries has been observed, despite the fact that sugar consumption was maintained and/or was increasing during the same lapse of time . A sugar-caries relationship cannot be established in most of the industrialized countries and the dietary factor is not as preponderant in the caries process as it used to be two decades ago . The factors which seem to contribute the most significantly to the cariogenicity of the diet are the frequency of carbohydrate ingestion and eating patterns . The relative cariogenicity of food is not correlated with the amount of carbohydrate it contains . Even if sucrose remains the most important sugar consumed in sweets, beverages and confectionery products, all fermentable-carbohydrate foods can be involved in the caries process . The use of chewing gum and other xylitol-containing products have resulted in defined reduction in caries and represent interesting alternatives for high-caries-risk populations . Caries risk and oral health assessments as well as the evaluation of oral hygiene procedures and fluoride exposure should become essential tools in dietary counselling . People who receive optimum fluoride exposure and follow regular oral hygiene measures can safely use dietary carbohydrates, preferably during meals and two to three times daily in snacks or drinks.

J Dairy Sci, 1997 Apr, 80(4), 681 - 91
Influence of level of concentrate allocation and fermentability of forage fiber on chewing behavior and production of dairy cows; Robinson PH et al.; Nine midlactation dairy cows were offered one of three mixed silage rations with neutral detergent fiber (NDF) that was similar in concentration but different in fermentability . Differences in fermentability were achieved by substituting a high quality alfalfa silage for a low quality alfalfa silage and substituting a combination of ryegrass and timothy silages for a barley silage . In addition, concentrate was allocated at 0.30, 0.82, or 1.37 kg of dry matter/kg of dry matter intake (DMI) from the mixed silage ration . As expected, the NDF content of the mixed silage ration did not differ, although fermentability of NDF increased numerically as forage quality increased . Intake of NDF increased linearly, and DMI tended to increase linearly, as fiber fermentability of the mixed silage ration increased . In addition, cows produced more milk, milk fat, and milk protein and generated more total and milk energy . The calculated concentration of net energy for lactation of the total diet also increased . Results support the concept that NDF quality influences and can be used to predict voluntary feed intake, at least in relatively high producing dairy cows . The DMI increased, and intake of NDF and crude protein declined, as the allocation of concentrate increased . In addition, as concentrate allocation increased, cows spent less time eating and ruminating and more time resting and produced more milk, milk protein, and milk lactose . Cows also generated more total energy and milk energy, although, despite a sharp decrease in the forage proportion of the diet, the calculated energy density of the diet did not differ among concentrate levels . The lack of significant interactions between concentrate level and fiber fermentability for any parameter measured supports the contention that high quality forage is critical to a successful dairy ration, regardless of the proportion of forage in the diet.

Microbiology, 1997 Apr, 143 ( Pt 4), 1175 - 80
The ability of Escherichia coli O157:H7 to decrease its intracellular pH and resist the toxicity of acetic acid; Diez-Gonzalez F et al.; Batch cultures of Escherichia coli K-12 grew well in an anaerobic glucose medium at pH 5.9, but even small amounts of acetate (20 mM) inhibited growth and fermentation . E . coli O157:H7 was at least fourfold more resistant to acetate than K-12 . Continuous cultures of E . coli K-12 (pH 5.9, dilution rate 0.085 h-1) did not wash out until the sodium acetate concentration in the input medium was 80 mM, whereas E . coli O157:H7 persisted until the sodium acetate concentration was 160 mM . E . coli K-12 cell accumulated as much as 500 mM acetate, but the intracellular acetate concentration of O157:H7 was never greater than 300 mM . Differences in acetate accumulation could be explained by intracellular pH and the transmembrane pH gradient (delta pH) . E . coli K-12 maintained a more or less constant delta pH (intracellular pH 6.8), but E . coli O157:H7 let its delta pH decrease from 0.9 to 0.2 units as sodium acetate was added to the medium . Sodium acetate increased the rate of glucose consumption, but there was little evidence to support the idea that acetate was creating a futile cycle of protons . Increases in glucose consumption rate could be explained by increases in D-lactate production and decreases in ATP production . Intracellular acetate was initially lower than the amount predicted by delta pH, but intracellular acetate and delta pH were in equilibrium when the external acetate concentrations were high . Based on these results, the acetate tolerance of O157:H7 can be explained by fundamental differences in metabolism and intracellular pH regulation . By decreasing the intracellular pH and producing large amounts of D-lactate, O157:H7 is able to decrease delta pH and prevent toxic accumulations of intracellular acetate anion.

Microbiology, 1997 Apr, 143 ( Pt 4), 1133 - 9
Metabolic flux response to salt-induced stress in the halotolerant yeast Debaryomyces hansenii; Neves ML et al.; The toxic effect of NaCl and KCl on growth of the marine yeast Debaryomyces hansenii on glucose or glycerol was studied . Above a threshold value, both salts reduced the specific growth rate, specific glucose and glycerol respiration rates and specific glucose fermentation rate, as well as biomass yields . The exponential inhibition constant, k, and minimum toxic concentration, Cmin were similar for all physiological parameters assayed . The effect of either salt on the specific activity of several glycolytic enzymes showed a similar inhibition pattern, although at much lower salt concentrations compared with the physiological parameters . In agreement with published results on glycerol phosphate dehydrogenase stimulation by salt, we present evidence that a general glycolytic flux deviation could occur naturally during salt stress, due to the intrinsic sensitivity of the glycolytic enzymes to intracellular ion concentrations.

J Appl Microbiol, 1997 Apr, 82(4), 511 - 8
Evaluation of the Phene Plate generalized microplate for metabolic fingerprinting and for measuring fermentative capacity of mixed bacterial populations; Katouli M et al.; The Phene Plate (PhP) generalized microplate for metabolic fingerprinting and for measuring the fermentative capacity of intestinal bacteria was evaluated . Twelve bacterial species, representing those commonly found in the intestine of humans and animals were employed . Mixtures of bacteria were inoculated in duplicate onto the PhP microplates . Anaerobic conditions were achieved by either incubating the plates under nitrogen atmosphere or by covering the microplates with mineral oil before incubation . Different metabolic fingerprints based on the pattern of substrate utilization were obtained for each bacterial mixture . Metabolic responses of bacterial samples were similar under both anaerobic conditions although the rate of carbohydrate utilization was higher in plates covered with mineral oil . A fermentative capacity value based on the number and the degree of fermented carbohydrates was established for each mixture which differed as the composition of the mixture changed but in general it was higher in samples with more bacterial species . The PhP generalized microplate may thus be used for studying the functional status and metabolic potential of intestinal floras.

J Wildl Dis, 1997 Apr, 33(2), 336 - 9
Mycoplasmal conjunctivitis in a European starling; Frasca S Jr et al.; Bilateral conjunctivitis and episcleritis were identified in an adult European starling (Sturnus vulgaris) . A novel mycoplasma species, Mycoplasma sturni, was isolated in pure culture from the conjunctiva of both eyes . The clinical presentation was similar to that of conjunctivitis in house finches (Carpodacus mexicanus) caused by Mycoplasma gallisepticum . However, the histologic lesions were distinct, by the presence of ulceration and by the absence of epithelial hyperplasia and lymphoplasmacytic infiltration {corrected} . Mycoplasma sturni ferments glucose, does not hemadsorb or hemagglutinate chicken erythrocytes, and grows rapidly at 37 C in comparison to other Mycoplasma spp . The role of M . sturni in conjunctivitis in other passerine species is presently unknown.

J Med Microbiol, 1997 Apr, 46(4), 348 - 53
Differentiation of strains of Mycoplasma fermentans from various sources by pyrolysis mass spectrometry; Hannan PC et al.; Mycoplasma fermentans has attracted much interest both as a cofactor for the progression of AIDS and as a pathogenic agent in non-AIDS related diseases . Previous studies with serological and genetic techniques suggest that M . fermentans represents a homogeneous group of organisms, with no significant differences identified among the strains examined . In this study, 25 cultures of M . fermentans, including isolates from human sources and tissue culture cells, were compared by pyrolysis mass spectrometry (PMS) . It was possible to distinguish the 'type' strain PG-18 from an AIDS-associated M . fermentans strain 'incognitus' by this technique . PMS was also able to differentiate laboratory-induced aminoglycoside-resistant variants from their fully susceptible parents . Four AIDS-associated isolates were distinguished from each other, whilst five European cell culture isolates were shown to be closely related, as were six M . fermentans isolates from an outbreak of acute respiratory infection in Canada . PMS has proved useful in distinguishing isolates of M . fermentans, providing epidemiological data . In addition, PMS may help in determining the likely origin of a given isolate, and in the future may be of use in assessing the role of this micro-organism in human disease.

Biotechnol Appl Biochem, 1997 Apr, 25 ( Pt 2), 159 - 68
A study of combined filtration and adsorption on nylon-based dye-affinity membranes: separation of recombinant L-alanine dehydrogenase from crude fermentation broth; Weissenborn M et al.; Dextran, hydroxyethylcellulose (HEC), and poly(vinyl alcohol) PVA were covalently linked to bisoxirane-activated nylon membranes . Cibacron Blue F3G-A was immobilized on to these membranes to yield a dye-affinity membrane . The hydrodynamic permeability of affinity membranes was reduced to approximately 50% of that of the original Nylon membrane due to extension of polymer coils into flow-through pores . Adsorption of pre-purified human serum albumin (HSA) and malate dehydrogenase (MDH) displayed highest maximum binding capacities on HEC-coated dye-ligand-affinity membranes, ranging from (163 micrograms/cm2 for HSA to 316 micrograms/cm2 for MDH . The protein recovery of HSA was 100% on dextran-coated membranes compared with 70% on PVA-coated membranes, whereas almost 100% recovery was found for MDH, independent of the polymer . Application of crude supernatant from recombinant Escherichia coli yielded purification factors of 7.4, 8.9 and 11.2 for recombinant alanine dehydrogenase from Mycobacterium tuberculosis for HEC-, dextran- and PVA-coated membranes respectively . Dynamic capacities decreased remarkably to approximately 3 micrograms/cm2 due to co-adsorption of host proteins . The presence of cell debris caused only a slight decrease of purification factors, but a dramatic decrease of the permeability of affinity membranes due to development of a particle layer in front of the membranes . Although enzyme recoveries were up to 90% using cell-free supernatant, more than 50% of the product was lost due to polarization, concentration and rejection at particle layers when using crude homogenates . In order to further improve this integrated downstream process, sophisticated membrane techniques are required by which the formation of a filter cake is circumvented . Further refinement of polymer-coated membranes would not help one to avoid this problem.

Protein Expr Purif, 1997 Apr, 9(3), 331 - 6
Synthetic leaders with potential BiP binding mediate high-yield secretion of correctly folded insulin precursors from Saccharomyces cerevisiae; Kjeldsen T et al.; Secretion leaders are essential for expression of many heterologous proteins including insulin in yeast . The function of secretion leaders and their interaction with the secretory pathway is not clear . To determine what constitutes functional pre-pro-leader sequences in Saccharomyces cerevisiae, synthetic leader sequences for secretion of the insulin precursor were developed by a combination of rational design and stepwise systematic optimization . The synthetic leaders efficiently facilitate secretion of the insulin precursor from S . cerevisiae when compared with the alpha-factor leader, leading to a high yield of correctly folded insulin precursor in the culture supernatant . The synthetic leaders feature two potential N-linked glycosylation sites which are efficiently glycosylated during secretion . Pulse-chase analysis indicates that the synthetic leaders/insulin precursor fusion protein have a prolonged residence in the endoplasmic reticulum compared to the alpha-factor leader/insulin precursor fusion protein . The longer transition time in the endoplasmic reticulum mediated by the synthetic leaders might provide additional time for correct folding of the insulin precursor and account for the increased fermentation yield.

Proc Soc Exp Biol Med, 1997 Apr, 214(4), 359 - 66
High-level expression of H-ras and c-myc oncogenes in mycoplasma-mediated malignant cell transformation; Zhang B et al.; C3H mouse embryo cells, which normally have low inherent spontaneous transformation, underwent malignant transformation while chronically infected with Mycoplasma fermentans or Mycoplasma penetrans . This mycoplasma-mediated oncogenic process had long latency (more than 7 weeks of persistent mycoplasmal infection) and showed multistage progression characterized by reversibility and irreversibility of malignant properties upon removal of M . fermentans from culture . Marked expression of H-ras and c-myc mRNA, but not N-myc, src, N-ras, or p53 mRNA, was found in the mycoplasma-transformed C3H cells that exhibited characteristic malignant properties of morphological changes and uncontrolled cell growth . However, at least up to the eleventh week of persistent mycoplasma infection, the marked expression of H-ras or c-myc mRNA in C3H cells depended on continued presence of the mycoplasma in culture . H-ras or c-myc mRNA rapidly declined to the undetectable low levels of nontransformed parental C3H cells, and all malignant properties of the once-fully-transformed C3H cells quickly reversed, if M . fermentans was eradicated from culture . In comparison, infection with M . penetrans for 7 or 11 weeks also induced a high level of H-ras, but not c-myc, mRNA expression in C3H cells . Despite having prominent amount of steady-state H-ras mRNA, these M . penetrans-infected C3H cells did not show any sign of malignant transformation . Thus, marked expression of H-ras gene alone was not sufficient to effect transformation in C3H cells . Interestingly, after a further prolonged (18 weeks) infection with either M . fermentans or M . penetrans, C3H cells revealed prominent chromosomal changes, expressed constitutively (with or without the presence of the transforming mycoplasmas) at high levels of both H-ras and c-myc mRNA and became permanently transformed . These cells were able to form tumors in animals.

J Anim Sci, 1997 Apr, 75(4), 1167 - 78
Free amino acid supplementation to steers: effects on ruminal fermentation and performance; Campbell CG et al.; Three studies were conducted to evaluate amino acid utilization by cattle . In Exp . 1, five steers (580 kg) were fed 86% rolled corn diets with mixtures of amino acids containing up to 6 g/d DL-Met, 24 g/d L-Lys, 6 g/d L-Thr, and 3 g/d L-Trp . Treatments had little effect on ruminal fermentation, diet digestibility, N flow to the duodenum, or microbial efficiency . Ruminal concentrations of Met and Lys increased linearly (P < .05) with amino acid supplementation, whereas Thr responded quadratically, and Trp was not altered . In Exp . 2, four steers (414 kg) were used to measure effects of dietary monensin or laidlomycin propionate in high-grain diets supplemented with amino acids . Ionophores had no significant effect on ruminal fermentation or outflows of amino acids from the rumen . In Exp . 3, 100 steers (287 kg initial BW) were fed diets containing 1% of a nonprotein N source . Treatments were 1) no supplemental N (UREA), 2) UREA plus soybean meal (SBM), 3) UREA plus 2 g/d DL-Met, 8 g/d L-Lys, 2 g/d L-Thr, and 1 g/d L-Trp, or 4) UREA plus 4 g/d DL-Met, 16 g/d L-Lys, 4 g/d L-Thr, and 2 g/d L-Trp . During the growing period (diets based on whole-plant milo silage), gains were higher for SBM-supplemented steers than for UREA steers and intermediate for steers supplemented with amino acids . Few significant differences in performance were observed among treatments during the finishing phase (diets based on dry-rolled corn) or for the entire experiment, but cattle fed SBM or amino acids tended to be fatter and have better marbling scores and quality grades . Amino acids did not greatly alter ruminal fermentation or cattle performance.

J Anim Sci, 1997 Apr, 75(4), 1140 - 8
The effect of preservation method on the neutral detergent soluble fraction of forages; Doane PH et al.; Fermentation of neutral detergent solubles (NDS) was assessed using a 3 x 3 x 3 factorial arrangement . Three forage species (alfalfa, bromegrass, and orchardgrass) were collected at three maturities and preserved either by freeze drying, oven drying at 50 degrees C, or by ensiling . Each feed sample and its isolated NDF were fermented in vitro and gas production was monitored . Gas yield from NDS was determined as the difference between gas from the unfractionated forage and from its respective NDF . The forages ranged from 23 (immature alfalfa) to 68% NDF (mature orchardgrass) . The silages were well fermented with a final pH of < or = 4.5 . Increasing maturity decreased the final gas volume but did not change the rate of gas production from the NDS fraction . There was little difference in gas production between freeze-dried and oven-dried forage samples . Ensiling decreased gas yield from the unfractionated forage . The rate of gas production from the NDS fraction of the ensiled forages decreased an average of .05 h-1 compared with the freeze-dried sample . Gas yield from the NDS fraction decreased (from the freeze-dried sample) between 7 and 36% upon ensiling . The curve substraction approach can be used to evaluate the effects of ensiling on the neutral detergent-soluble fraction of forages.

J Anim Sci, 1997 Apr, 75(4), 1100 - 11
Ardacin for steers grazing endophyte-free fescue pasture: effects on live weight gain, forage intake, nitrogen and fiber digestion, ruminal fluid kinetics, ruminal fermentation, and serum hormones and metabolites; Judkins MB et al.; Growth and digestion studies were conducted to evaluate the use of ardacin as a feedgrade antibiotic for enhancing digestive function and growth in grazing steers . In Exp . 1, 90 yearling steers (average initial BW of 248 kg) used in a randomized complete block design (block = weight group) grazed fescue pasture without supplementation (CON) or with daily supplements (DM basis) of .4% of BW supplemental ground corn (CRN) or .4% of BW supplemental corn supplying 120 mg of ardacin (ARD) . In Exp . 2, 12 ruminally and duodenally cannulated steers and three ruminally cannulated steers (Hereford x Angus; average BW of 347 kg) were used to evaluate the effects of the same supplements used in Exp . 1 on ruminal fermentation and digestion . In Exp . 1, ARD-supplemented steers weighed more (P < .01) at the conclusion of the study than CRN steers, which together weighed more (P < .01) than CON steers . Average daily gain was greater (P < .10) in supplemented than in CON steers; ARD steers had greater (P < .01) ADG than CRN steers . In Exp . 2, forage intake and harvesting efficiency did not vary (P > .10) with supplementation or type of supplement, but total intake reflected (P = .03) the addition of corn to the forage diet . Addition of ardacin increased (P = .02) ruminal pH compared with CRN steers . Ardacin decreased ruminal molar proportions of acetate and increased (P = .01) propionate proportions when compared with CRN steers . Total tract N digestibility was affected (P < .10) by supplementation and by addition of ardacin to the diet . Addition of ardacin to the ground corn supplement increased ADG, in part by enhancing acetate:propionate ratios and increasing N digestion.

J Nutr, 1997 Apr, 127(4), 615 - 22
A high amylose (amylomaize) starch raises proximal large bowel starch and increases colon length in pigs; Topping DL et al.; Young male pigs consumed a diet of fatty minced beef, safflower oil, skim milk powder, sucrose, cornstarch and wheat bran . Starch provided 50% of total daily energy either as low amylose cornstarch, high amylose (amylomaize) cornstarch or as a 50/50 mixture of corn and high amylose starch . Neither feed intake nor body weight gain as affected by dietary starch . Final plasma cholesterol concentrations were significantly higher than initial values in pigs fed the 50/50 mixture of corn and high amylose starch . Biliary concentrations of lithocholate and deoxycholate were lower in pigs fed high amylose starch . Large bowel length correlated positively with the dietary content of high amylose starch . Concentrations of butyrate in portal venous plasma were significantly lower in pigs fed high amylose starch than in those fed cornstarch . Neither large bowel digesta mass nor the concentrations of total or individual volatile fatty acids were affected by diet . However, the pool of propionate in the proximal colon and the concentration of propionate in feces were higher in pigs fed amylose starch . Concentrations of starch were uniformly low along the large bowel and were unaffected by starch type . In pigs with cecal cannula, digesta starch concentrations were higher with high amylose starch than with cornstarch . Electron micrographic examination of high amylose starch granules from these animals showed etching patterns similar to those of granules obtained from human ileostomy effluent . It appears that high amylose starch contributes to large bowel bacterial fermentation in the pig but that its utilization may be relatively rapid.

Curr Genet, 1997 Apr, 31(4), 281 - 91
Heme regulates SOD2 transcription by activation and repression in Saccharomyces cerevisiae; Pinkham JL et al.; SOD2 encodes the Saccharomyces cerevisiae manganese superoxide dismutase (MnSOD), a mitochondrial matrix protein . Heme regulates SOD2 transcription during both fermentative and respiratory growth by three mechanisms . First, SOD2 transcription is activated 10-fold by growth on a non-fermentable carbon source via the heme activator protein (Hap) 2-3-4-5 complex . Second, SOD2 transcription is repressed 90% in the absence of heme . Finally, Hap1p, a heme-binding, DNA-binding transcription activator, is required for full SOD2 expression during growth on glucose . Extensive mutational analysis of the SOD2 promoter reveals three cis elements that mediate heme-dependent regulation . Interestingly, the DNA sequences necessary for repression in the absence of heme overlap those that mediate Hap1p activation . Genetic results suggest a novel role for Hap1p in the regulation of repression in the absence of heme.

Appl Environ Microbiol, 1997 Apr, 63(4), 1382 - 8
Novel anaerobic ultramicrobacteria belonging to the Verrucomicrobiales lineage of bacterial descent isolated by dilution culture from anoxic rice paddy soil; Janssen PH et al.; The use of dilution culture techniques to cultivate saccharolytic bacteria present in the anoxic soil of flooded rice microcosms allowed the isolation of three new strains of bacteria, typified by their small cell sizes, with culturable numbers estimated at between 1.2 x 10(5) and 7.3 x 10(5) cells per g of dry soil . The average cell volumes of all three strains were 0.03 to 0.04 microns3, and therefore they can be termed ultramicrobacteria or "dwarf cells." The small cell size is a stable characteristic, even when the organisms grow at high substrate concentrations, and thus is not a starvation response . All three strains have genomic DNA with a mol% G+C ratio of about 63, are gram negative, and are motile by means of a single flagellum . The three new isolates utilized only sugars and some sugar polymers as substrates for growth . The metabolism is strictly fermentative, but the new strains are oxygen tolerant . Sugars are metabolized to acetate, propionate, and succinate . Hydrogen production was not significant . In the presence of 0.2 atm of oxygen, the fermentation end products or ratios did not change . The phylogenetic analysis on the basis of 16S ribosomal DNA (rDNA) sequence comparisons indicates that the new isolates belong to a branch of the Verrucomicrobiales lineage and are closely related to a cloned 16S rDNA sequence (PAD7) recovered from rice paddy field soil from Japan . The isolation of these three strains belonging to the order Verrucomicrobiales from a model rice paddy system, in which rice was grown in soil from an Italian rice field, provides some information on the possible physiology and phenotype of the organism represented by the cloned 16S rDNA sequence PAD7 . The new isolates also extend our knowledge on the phenotypic and phylogenetic depths of members of the order Verrucomicrobiales, to date acquired mainly from cloned 16S rDNA sequences from soils and other habitats.

Appl Environ Microbiol, 1997 Apr, 63(4), 1261 - 7
Intraspecific genetic diversity of Oenococcus oeni as derived from DNA fingerprinting and sequence analyses; Zavaleta AI et al.; The intraspecific genetic diversity of Oenococcus oeni, the key organism in the malolactic fermentation of wine, has been evaluated by random amplified polymorphic DNA (RAPD), ribotyping, small-plasmid content, and sequencing of RAPD markers with widespread distribution among the strains . Collection strains representing the diversity of this species have been studied together with some new isolates, many of which were obtained from wines produced by spontaneous malolactic fermentation . The RAPD profiles were strain specific and discerned two main groups of strains coincident with clusters obtained by macrorestriction typing in a previous work . Ribotyping and the conservation of RAPD markers indicates that O . oeni is a relatively homogeneous species . Furthermore, identical DNA sequences of some RAPD markers among strains representative of the most divergent RAPD clusters indicates that O . oeni is indeed a phylogenetically tight group, probably corresponding to a single clone, or clonal line of descent, specialized to grow in the wine environment and universally spread.

Am J Clin Nutr, 1997 Apr, 65(4), 927 - 33
Colonic fermentation capacity in vitro: development during weaning in breast-fed infants is slower for complex carbohydrates than for sugars; Parrett AM et al.; Fresh feces from 27 healthy infants-12 breastfed (complete, exclusive breast-feeding), 7 in early weaning (partial, high breast-feeding), and 8 in late weaning (partial, low breast-feeding)-were cultured with simple and complex carbohydrates in vitro to test the hypothesis that colonic fermentation capacity for carbohydrates increases during weaning . Infants in all three groups were able to ferment sugars, with no significant differences in median total short-chain fatty acid (SCFA) concentrations (mmol/L): preweaning, 56.4(range: 0-77.6); early weaning 68.5(range: 57.9-98.8); late weaning, 61.3(range: 28.6-120.4) for glucose . Preweaned infants were less able to ferment oligosaccharides and complex carbohydrates than were weaned infants (P < 0.05) . Ability to ferment raftilose was higher in early weaning; median total SCFA concentrations (mmol/L) were as follows: preweaning 31.0 (range: 3.6-48.9), early weaning 57.1 (range: 2.5-70.6), late weaning 68.6 (range: 22.0-113.4) (P < 0.05) . Ability to ferment complex carbohydrates did not develop until late weaning; median total SCFA concentrations for guar gum (mmol/L) were as follows: preweaning 6.4 (range: 0.1-57.3), early weaning 18.4 (range: 0.0-40.5), late weaning 45.4 (range: 15.6-62.1) (P < 0.05, preweaning and early weaning compared with late weaning) . Development of the ability to ferment complex carbohydrate was slow . Cultures of feces from preweaned infants produced eight times more SCFAs with glucose than with complex carbohydrates, at early weaning there was a threefold difference and by late weaning the difference was only 25%, but this was still only 42% of the SCFAs produced by cultures of adult feces . These data suggest that for the complex carbohydrates tested, colonic fermentation is likely to contribute only a small proportion of daily energy needs of weaning infants.

Nat Biotechnol, 1997 Apr, 15(4), 349 - 53
Complete conversion of antibiotic precursor to pristinamycin IIA by overexpression of Streptomyces pristinaespiralis biosynthetic genes; Sezonov G et al.; A Streptomyces pristinaespiralis strain, which produces a streptogramin antibiotic pristinamycin II (PII) as a mixture of two biologically active molecules PIIB and PIIA, was genetically engineered to produce exclusively PIIA . The snaA,B genes, which encode a PIIA synthase that performs oxidation of the precursor (PIIB) to the final product (PIIA), were integrated in the chromosome of S . pristinaespiralis using an integrative derivative of the pSAM2 genetic element from Streptomyces ambofaciens . Integration was due to site-specific recombination at the attB site of S . pristinaespiralis, and no homologous recombination at the snaA,B locus was observed . The attB site of S . pristinaespiralis was sequenced and found to overlap the 3' end of a pro-tRNA gene . The integrants were stable in industrial conditions of pristinamycin production and showed no decrease in PII biosynthesis . Western blot analysis showed a constant production of the PIIA synthase in the overall fermentation process due to expression of the cloned snaA,B genes from the constitutive ermE promoter . This allows the complete conversion of the PIIB form into PIIA.

Soc Sci Med, 1997 Apr, 44(7), 1065 - 8
Potential use of traditional fermented foods for weaning in Zimbabwe; Simango C; The current interest in the use of traditional fermented and malted foods for weaning is their potential to reduce the transmission of bacterial enteric pathogens through contaminated weaning foods as well as improving the nutritional value of the foods . This study was carried out to investigate the potential use of traditional fermented and malted foods for weaning in rural areas . Information was obtained by interviewing randomly selected 150 rural women with children under five years old . Ninety seven percent of the women had knowledge of some traditional fermented foods . The commonest fermented foods known by the women were mahewu (traditional fermented and malted sour, non-alcoholic cereal gruel), sour milk and sour porridge . Most of the women indicated that mahewu (94%), sour milk, (87%) and sour porridge (71%) were consumed by all family members . The majority of the women gave the fermented foods to infants from the age of four months . Although most of the infants were introduced to the fermented and malted foods from the age of four months, the foods were not given to infants very often, with the exception of mahewu . The storage period of the fermented foods ranged from one to three days . The results of this study show that mahewu, sour milk and sour porridge have a potential for use as weaning foods if they are promoted.

J Mol Evol, 1997 Apr, 44(4), 354 - 60
Energy from redox disproportionation of sugar carbon drives biotic and abiotic synthesis; Weber AL; To identify the energy source that drives the biosynthesis of amino acids, lipids, and nucleotides from glucose, we calculated the free energy change due to redox disproportionation of the substrate carbon of (1) 26-carbon fermentation reactions and (2) the biosynthesis of amino acids and lipids of E . coli from glucose . The free energy (cal/mmol of carbon) of these reactions was plotted as a function of the degree of redox disproportionation of carbon (disproportionative electron transfers (mmol)/mmol of carbon) . The zero intercept and proportionality between energy yield and degree of redox disporportionation exhibited by this plot demonstrate that redox disproportionation is the principal energy source of these redox reactions (slope of linear fit = -10.4 cal/mmol of disproportionative electron transfers) . The energy and disproportionation values of E . coli amino acid and lipid biosynthesis from glucose lie near this linear curve fit with redox disproportionation accounting for 84% and 96% (and ATP only 6% and 1%) of the total energy of amino acid and lipid biosynthesis, respectively . These observations establish that redox disproportionation of carbon, and not ATP, is the primary energy source driving amino acid and lipid biosynthesis from glucose . In contrast, we found that nucleotide biosynthesis involves very little redox disproportionation, and consequently depends almost entirely on ATP for energy . The function of sugar redox disproportionation as the major source of free energy for the biosynthesis of amino acids and lipids suggests that sugar disproportionation played a central role in the origin of metabolism, and probably the origin of life.

Curr Opin Biotechnol, 1997 Apr 1, 8(2), 160 - 4
Fermentation monitoring and process control; Ritzka A et al.; The use of modern analytical online methods such as two-dimensional fluorescence measurements gives new insights into bioprocesses . With the resulting data, it is not only possible to better understand and document, for example, biotransformations, but also to develop efficient control strategies that lead to better productivity and lower costs.

Arch Microbiol, 1997 Apr, 167(4), 217 - 32
Comparative analysis of Embden-Meyerhof and Entner-Doudoroff glycolytic pathways in hyperthermophilic archaea and the bacterium Thermotoga; Selig M et al.; The Embden-Meyerhof (EM) or Entner-Doudoroff (ED) pathways of sugar degradation were analyzed in representative species of the hyperthermophilic archaeal genera Thermococcus, Desulfurococcus, Thermoproteus, and Sulfolobus, and in the hyperthermophilic (eu)bacterial genus Thermotoga . The analyses included (1) determination of 13C-labeling patterns by 1H- and 13C-NMR spectroscopy of fermentation products derived from pyruvate after fermentation of specifically 13C-labeled glucose by cell suspensions, (2) identification of intermediates of sugar degradation after conversion of 14C-labeled glucose by cell extracts, and (3) measurements of enzyme activities in cell extracts . Thermococcus celer and Thermococcus litoralis fermented 13C-glucose to acetate and alanine via a modified EM pathway (100%) . This modification involves ADP-dependent hexokinase, 6-phosphofructokinase, and glyceraldehyde-3-phosphate:ferredoxin oxidoreductase (GAP:FdOR) . Desulfurococcus amylolyticus fermented 13C-glucose to acetate via a modified EM pathway in which GAP:FdOR replaces GAP-DH/phosphoglycerate kinase . Thermoproteus tenax fermented 13C-glucose to low amounts of acetate and alanine via simultaneous operation of the EM pathway (85%) and the ED pathway (15%) . Aerobic Sulfolobus acidocaldarius fermented 13C-labeled glucose to low amounts of acetate and alanine exclusively via the ED pathway . The anaerobic (eu)bacterium Thermotoga maritima fermented 13C-glucose to acetate and lactate via the EM pathway (85%) and the ED pathway (15%) . Cell extracts contained glucose-6-phosphate dehydrogenase and 2-keto-3-deoxy-6-phosphogluconate aldolase, key enzymes of the conventional phosphorylated ED pathway, and, as reported previously, all enzymes of the conventional EM pathway . In conclusion, glucose was degraded by hyperthermophilic archaea to pyruvate either via modified EM pathways with different types of hexose kinases and GAP-oxidizing enzymes, by the nonphosphorylated ED pathway, or by a combination of both pathways . In contrast, glucose catabolism in the hyperthermophilic (eu)bacterium Thermotoga involves the conventional forms of the EM and ED pathways . The data are in accordance with various previous reports.

Gene, 1997 Mar 25, 188(1), 77 - 84
Cloning and phylogenetic analysis of the genes encoding acetohydroxyacid synthase from the archaeon Methanococcus aeolicus; Bowen TL et al.; The gene for acetohydroxyacid synthase (AHAS) was cloned from the archaeon Methanococcus aeolicus . Contrary to biochemical studies {Xing, R . and Whitman, W.B . (1994) J . Bacteriol . 176, 1207-1213} the enzyme was encoded by two open reading frames (ORFs) . Based on sequence homology, these ORFs were designated ilvB and ilvN for the large and small subunits of AHAS, respectively . A putative methanogen promoter preceded ilvB-ilvN, and a potential internal promoter was found upstream of ilvN . ilvB encoded a 65-kDa protein, which agreed well with the measured value for the purified enzyme . ilvN encoded a 19-kDa protein, which fell within the range of M(r) of small subunits from other sources . Phylogenetic analysis of the deduced amino acid sequence of ilvB showed a close relationship between the AHAS of Bacteria and Archaea, to the exclusion of other enzymes in this family, including pyruvate oxidase, glyoxylate carboligase, pyruvate decarboxylase, and the acetolactate synthase found in fermentative Bacteria . Thus, this family of enzymes probably arose prior to the divergence of the Bacteria and Archaea . Moreover, the higher plant AHAS and the red algal AHAS were related to the AHAS II of Escherichia coli and the cyanobacterial AHAS, respectively . For this reason, these genes appear to have been acquired by the Eucarya during the endosymbiosis that gave rise to the mitochondrion and chloroplast, respectively . One of the ORFs in the Methanococcus jannaschii genome possesses high similarity to the M . aeolicus ilvB, indicating that it is an authentic AHAS.

Cancer Lett, 1997 Mar 19, 114(1-2), 47 - 9
Characterisation of the binding capacities and affinities of wheat bran, fruit and vegetable fibres for MeIQx, before and after fermentation; Ryden P et al.; Binding capacities and affinities of dietary fibres and fermented fibre residues for MeIQx are much higher for brans than for fruit and vegetable fibres . Bran residues concentrated distally in the colon would provide a substantial binding matrix . Small intestinal conditions are not so conducive to hydrophobic adsorption.

Int J Food Microbiol, 1997 Mar 18, 35(1), 29 - 39
Physiology and development of Pectinatus cerevisiiphilus and Pectinatus frisingensis, two strict anaerobic beer spoilage bacteria; Tholozan JL et al.; The genus Pectinatus was isolated recently and the deposited strains were classified as beer spoilage bacteria producing propionate as a major fermentation product . A recent investigation of this genus demonstrated the existence of two species: Pectinatus cerevisiiphilus, the type strain and Pectinatus frisingensis, a new species with a different pattern of growth substrates . Different culture media tested for both species demonstrated a higher specific growth rate for P . cerevisiiphilus . However, final biomass production was in every case around 20% higher in P . frisingensis . A 400% decrease of final biomass production was measured when the species were cultivated on poor culture medium; this decrease was found to be broadly proportional to amounts of acetate excreted in the medium . Both species produced CO2 from glucose; however, no significant modifications of biomass and volatile fatty acid production were demonstrated when varying head space composition with regard to CO2 levels . Growth experiments on glucose with increasing amounts of ethanol added in the culture, revealed a higher sensitivity of P . cerevisiiphilus to ethanol inhibition . Ethanol concentrations over 1.7 M resulted in a complete inhibition of growth for both Pectinatus species . Combined effects of culture medium pH, lactate, and glucose concentrations, demonstrated the prevailing role of glucose in the development of the bacteria . However, these three parameters had a different influence on growth characteristics of both Pectinatus species . P cerevisiiphilus grew very poorly with a glucose concentration of 5 mM for pH values below 4.1 . This species had optimal pH for growth between 6 and 6.2 and it excreted increasing amounts of acetate with increase of pH, glucose or lactate in the culture medium . P . frisingensis showed a wide range of pH allowing a good growth . For glucose concentrations below 20 mM, highest final biomass productions were measured in the culture for pH values around 4.9; this also corresponded to a minimum in acetate excretion . The above results pointed at P . frisingensis as the prevailing species of Pectinatus in beer spoilage.

Biochem J, 1997 Mar 15, 322 ( Pt 3), 823 - 8
Glucose-independent inhibition of yeast plasma-membrane H+-ATPase by calmodulin antagonists; Romero I et al.; Glucose metabolism causes activation of the yeast plasma-membrane H+-ATPase . The molecular mechanism of this regulation is not known, but it is probably mediated by phosphorylation of the enzyme . The involvement in this process of several kinases has been suggested but their actual role has not been proved . The physiological role of a calmodulin-dependent protein kinase in glucose-induced activation was investigated by studying the effect of specific calmodulin antagonists on the glucose-induced ATPase kinetic changes in wild-type and two mutant strains affected in the glucose regulation of the enzyme . Preincubation of the cells with calmidazolium or compound 48/80 impeded the increase in ATPase activity by reducing the Vmax of the enzyme without modifying the apparent affinity for ATP in the three strains . In one mutant, pma1-T912A, the putative calmodulin-dependent protein kinase-phosphorylatable Thr-912 was eliminated, and in the other, pma1-P536L, H+-ATPase was constitutively activated, suggesting that the antagonistic effect was not mediated by a calmodulin-dependent protein kinase and not related to glucose regulation . This was corroborated when the in vitro effect of the calmodulin antagonists on H+-ATPase activity was tested . Purified plasma membranes from glucose-starved or glucose-fermenting cells from both pma1-P890X, another constitutively activated ATPase mutant, and wild-type strains were preincubated with calmidazolium or melittin . In all cases, ATP hydrolysis was inhibited with an IC50 of approximately 1 microM . This inhibition was reversed by calmodulin . Analysis of the calmodulin-binding protein pattern in the plasma-membrane fraction eliminates ATPase as the calmodulin target protein . We conclude that H+-ATPase inhibition by calmodulin antagonists is mediated by an as yet unidentified calmodulin-dependent membrane protein.

FEMS Microbiol Lett, 1997 Mar 15, 148(2), 123 - 9
Molecular characterization of the Entamoeba histolytica enolase gene and modelling of the predicted protein; Hidalgo ME et al.; Entamoeba histolytica obtains its energy mainly from glucose fermentation . Enzymes involved in this pathway could be potential targets for antiparasite drugs . Here we report the molecular characterization of the E . histolytica enolase gene (Ehenl-I), which in a single copy is located on the 1.6 Mb chromosome . It is transcribed into a 1.4 kb mRNA which starts 13 nucleotides upstream of the ATG start codon . The sequence TATAAG, at -31, interacted with nuclear proteins suggesting that it has a TATA box function . Protein modelling allowed us to identify a putative specific region that differs from human enolase and could be a good target for the design of novel drugs against E . histolytica.

Biochem Biophys Res Commun, 1997 Mar 6, 232(1), 169 - 72
Butyrate stimulates cyclin D and p21 and inhibits cyclin-dependent kinase 2 expression in HT-29 colonic epithelial cells; Siavoshian S et al.; Sodium butyrate, a product of colonic fermentation of dietary fiber, has been shown to inhibit cell proliferation by blocking the cells in the G1 phase of the cell cycle . However, its mechanism of action is still unknown . We found that butyrate strongly stimulated cyclin D and p21/WAF1/CIP1 expression in HT-29 human colonic adenocarcinoma cells, in a dose dependent manner . These stimulations were associated with a decrease in cyclin-dependent kinase (cdk) 2 level, whereas cdk4 and cdk6 remained unchanged . Our results suggest that the inhibition of cell cycle progression by sodium butyrate may be explained by a modulation of cell cycle regulatory proteins such as cyclin D and p21.

Int J Food Microbiol, 1997 Mar 3, 34(3), 267 - 77
Effects of low temperatures (9-33 degrees C) and pH (3.3-5.7) in the loss of Saccharomyces cerevisiae viability by combining lethal concentrations of ethanol with octanoic and decanoic acids; Viegas CA et al.; Octanoic and decanoic acids increase the rate of loss of Saccharomyces cerevisiae viability caused by lethal concentrations of ethanol, the specific death rate being an exponential function of the acid concentration . The highly liposoluble decanoic acid is the most effective . The fatty acids deleterious effect increases at pH below pKa (4.9) mainly due to the increase of the undissociated form concentration . The temperature effects (range 9 33 degrees C; at pH 3.9) on the kinetics of the toxin(s)-induced death suggest that the deleterious action of ethanol, octanoic acid and decanoic acid have the same biological target sites, probably related to transport processes across membranes, particularly the plasma membrane . In fact, the enthalpies of activation of octanoic acid- and decanoic acid-enhanced-ethanol-induced death were similar and close to the enthalpy of activation of ethanol-induced death . This average value (delta H++ = 11.4 +/- 2.7 kcal/mol) is of the order of magnitude of that of solute transport across plasma membranes . Results clearly suggest the important contribution of octanoic and decanoic acids, combined with ethanol, in the loss of yeast viability at the last steps of industrial ethanolic fermentations, particularly those carried out at low or intermediate temperatures . They also support the combination of lipophilic acids with low pH in food preservation.

Cell Stress Chaperones, 1997 Mar, 2(1), 12 - 24
Hsp30, the integral plasma membrane heat shock protein of Saccharomyces cerevisiae, is a stress-inducible regulator of plasma membrane H(+)-ATPase; Piper PW et al.; Saccharomyces cerevisiae has a single integral plasma membrane heat shock protein (Hsp) . This Hsp30 is induced by several stresses, including heat shock, ethanol exposure, severe osmostress, weak organic acid exposure and glucose limitation . Plasma membrane H(+)-ATPase activities of heat shocked and weak acid-adapted, hsp30 mutant and wild-type cells, revealed that Hsp30 induction leads to a downregulation of the stress-stimulation of this H(+)-ATPase . Plasma membrane H(+)-ATPase activity consumes a substantial fraction of the ATP generated by the cell, a usage that will be increased by the H(+)-ATPase stimulation occurring with several Hsp30-inducing stresses . Hsp30 might therefore provide an energy conservation role, limiting excessive ATP consumption by plasma membrane H(+)-ATPase during prolonged stress exposure or glucose limitation . Consistent with the role of Hsp30 being energy conservation, Hsp30 null cultures give lower final biomass yields . They also have lower ATP levels, consistent with higher H(+)-ATPase activity, at the glucose exhaustion stage of batch fermentations (diauxic lag), when Hsp30 is normally induced . Loss of Hsp30 does not affect several stress tolerances but it extends the time needed for cells to adapt to growth under several stressful conditions where the maintenance of homeostasis will demand an unusually high usage of energy, hsp30 is the first yeast gene identified as both weak organic acid-inducible and assisting the adaptation to growth in the presence of these acids.

Mikrobiol Z, 1997 Mar-Apr, 59(2), 78 - 84
{The metabolism and bactericidal properties of the blood neutrophilic granulocytes in experimental typhoid intoxication}; Ovcharenko NI et al.; The levels of succinate dehydrogenase (SDG), lactate dehydrogenase (LDG), glucose-6-phosphate-dehydrogenase (G-6-PDG), myeloperoxydase (MPO), glycogen and cationic proteins were determined in the neutrophilic granulocytes of peripheral blood of 79 rabbits after experimental contamination by endotoxin of S . typhi . The bactericidal system of neutrophils was stimulated due to the depression of SDG, activation of LDG and G-6-PDG levels . Administration of indometacinum and chlotasolum blockaded the cyclooxygenase fermentative system of prostaglandin synthesis and thus decreased the activity of S . typhi endotoxin.

Food Chem Toxicol, 1997 Mar-Apr, 35(3-4), 315 - 22
Safety evaluation of lipase derived from Rhizopus oryzae: summary of toxicological data; Coenen TM et al.; A lipase enzyme, obtained from Rhizopus oryzae produced by a fermentation process was subjected to a series of toxicological tests to document the safety for use as a food additive . The enzyme product was examined for acute, subacute and subchronic oral toxicity, and mutagenic potential . An extensive literature search on the production organism has also been conducted . No evidence of (sub)acute oral toxicity or mutagenic potential was found . Administration of the lipase at dosages of 50, 200 and 1000 mg/kg body weight/day for 90 days did not induce noticeable signs of toxicity . A few minor changes in the chemical composition of the blood in the highest dose group were of no toxicological significance . The no-observed-adverse-effect level of the tox-batch in the subchronic toxicity study was 1000 mg/kg body weight/day . It can be concluded that no safety concerns were identified in the studies conducted with this lipase preparation derived from R . oryzae and produced under controlled fermentation conditions.

Baillieres Clin Gastroenterol, 1997 Mar, 11(1), 153 - 74
Nutrition and ulcerative colitis; Burke A et al.; The role of diet in the aetiology and pathogenesis of ulcerative colitis (UC) remains uncertain . Impaired utilization by colonocytes of butyrate, a product of bacterial fermentation of dietary carbohydrates escaping digestion, may be important . Sulphur-fermenting bacteria may be involved in this impaired utilization . Oxidative stress probably mediates tissue injury but is probably not of causative importance . Patients with UC are prone to malnutrition and its detrimental effects . However, there is no role for total parenteral nutrition and bowel rest as primary therapy for UC . The maintenance of adequate nutrition is very important, particularly in the peri-operative patient . In the absence of massive bleeding, perforation, toxic megacolon or obstruction, enteral rather than parenteral nutrition should be the mode of choice . Nutrients may be beneficial as adjuvant therapy . Butyrate enemas have improved patients with otherwise recalcitrant distal colitis in small studies . Non-cellulose fibre supplements are of benefit in rats with experimental colitis . Eicosapentaenoic acid in fish oil has a steroid-sparing effect which, although modest, is important, particularly in terms of reducing the risk of osteoporosis, but it seems to have no role in the patient with inactive disease . gamma-Linolenic acid and anti-oxidants also are showing promise . Nutrients may also modify the increased risk of colorectal carcinoma . Oxidative stress can damage tissue DNA but there are no data published at present on possible protection from oral anti-oxidants . Butyrate protects against experimental carcinogenesis in rats with experimental colitis . Folate supplementation is weakly associated with decreased incidence of cancer in UC patients when assessed retrospectively . Vigilance should be maintained for increased micronutrient requirements and supplements given as appropriate . Calcium and low-dose vitamin D should be given to patients on long-term steroids and folate to those on sulphasalazine.

J Sports Med Phys Fitness, 1997 Mar, 37(1), 18 - 23
Interpreting energy expenditure for anaerobic exercise and recovery: an anaerobic hypothesis; Scott CB; Energy expenditure during and after exercise is composed of aerobic and anaerobic bioenergetics and the energy demands of aerobic recovery . Current attempts to measure energy expenditure include an exercise oxygen uptake + oxygen debt (EPOC) measurement or, an oxygen deficit + exercise oxygen uptake measurement . This investigation illustrates how oxygen debt and oxygen deficit interpretation can effect a total energy expenditure measurement . It was hypothesized that the total energy expenditure for several intermittent bouts of exercise and recovery would be greater than for one bout of continuous exercise and recovery when equivalent work was compared . Exercise was performed under low-intensity and high-intensity conditions . Both oxygen debt and oxygen deficit methodology resulted in similar energy expenditure measurements for both intermittent and continuous exercise . This implies little to no recovery energy demand or considerable methodology errors . Differences in total energy expenditure were found when the oxygen deficit and parts of the oxygen debt (EPOC) were considered separate and independent (p < 0.05) . These differences can be accounted for when the data are interpreted utilizing thermodynamic (2nd law) and engineering (in-series efficiency) concepts rather than the heat equivalent of carbohydrate oxidation (20.9 kJ equals one liter of O2) . It is suggested that while oxygen uptake provides an excellent representation of aerobic metabolism during exercise and recovery, oxygen uptake may be an inadequate measure of the energetics of lactate production (fermentation) . In application, energy expenditure differences appear realistic only for high-intensity, intermittent exercise rather than lower intensity exercise.

Br J Rheumatol, 1997 Mar, 36(3), 310 - 4
Systematic detection of mycoplasmas by culture and polymerase chain reaction (PCR) procedures in 209 synovial fluid samples; Schaeverbeke T et al.; The objective was to investigate the presence of mycoplasmas in rheumatoid arthritis (RA) and other chronic arthritides . Samples of synovial fluid (SF) were systematically collected from all patients presenting with an articular effusion . Each sample was divided into three parts . The first was kept for cytological count and culture on standard media for pyogens and mycobacteria, the second was cultivated on specific media for mycoplasmas and the third frozen for subsequent study by polymerase chain reaction (PCR) . A total of 209 samples were studied . Half of the patients had inflammatory rheumatic diseases: RA (27), spondyloarthropathy (28), connective tissue disease (5), unclassified arthritis (45) . The remaining suffered from other conditions, including osteoarthritis (60), gouty arthritis (19), haemarthrosis (5), post-traumatic effusion (2) . Eight samples were positive by culture, two for Mycoplasma hominis; three for M . fermentans, one for M . salivarium, one for M . orale and one for Ureaplasma urealyticum . All the patients concerned had an inflammatory rheumatic disease: five had RA, one had psoriatic arthritis and two had unclassified arthritis . These results were confirmed by PCR in two cases (one M . fermentans, one U . urealyticum) . The lack of sensitivity of the conventional PCR assay on SF is discussed . Mycoplasmas were mainly detected in SF of RA patients . These results raise the question of the possible role of mycoplasmas in the triggering and maintenance of inflammatory rheumatic diseases, especially RA.

Eur J Biochem, 1997 Mar 1, 244(2), 371 - 7
The primary structure of Rhodoferax fermentans high-potential iron-sulfur protein, an electron donor to the photosynthetic reaction center; Van Driessche G et al.; The complete amino acid sequence of Rhodoferax fermentans high-potential iron-sulfur protein (Hipip), which is known to be an efficient electron donor to the photosynthetic reaction center, has been determined using both N-terminal and C-terminal analyses . The sequence contains 75 residues, with 11 positive charges, 10 negative charges, and one histidine residue . The molecular mass of apo-Hipip, determined by electrospray ionization mass spectrometry, is 7849.64 Da . Multiple sequence alignment, based both on primary and tertiary structure information, reveals conservation of Tyr19 and Gly75 (Chromatium vinosum numbering) in addition to the four {Fe4S4}-bound cysteines . The Hipip from Rf . fermentans is most similar (57% similarity) to the Hipip from Rubrivivax gelatinosus, a photosynthetic bacterium belonging to the beta-1 subgroup of the proteobacteria.

Appl Microbiol Biotechnol, 1997 Mar, 47(3), 250 - 4
Extracellular pH affects regulation of the pcbAB gene in Penicillium chrysogenum; Chu YW et al.; The effect of extracellular pH and dissolved oxygen on regulation of the pcbAB gene in P . chrysogenum was examined, using Northern analysis and a reporter gene fusion . It was found that ambient pH markedly affected levels of pcbAB mRNA whereas maintenance of dissolved oxygen concentration above 10% had no detectable effect . The presence of a DNA-binding protein, which binds upstream of the pcbAB translational start codon, was also related to ambient pH . In all fermentations, pcbAB mRNA was most abundant at around the late exponential/early stationary phase of a culture.

Antonie Van Leeuwenhoek, 1997 Mar, 71(3), 201 - 6
Physiological properties and fatty acid composition in Mucor circinelloides f . circinelloides; Botha A et al.; Sporangiospores of Mucor circinelloides f . circinelloides CBS108.16 could germinate and grow on a wide variety of carbon sources in synthetic liquid media . Growth was supported by aldoses which have the same configuration at carbon atom number two as glucose . Di- and trisaccharides consisting of D-glucopyranosyl moieties were assimilated, while polysaccharides like inuline and starch were also utilised . Various alcohols and organic acids could be assimilated, while the phenolic compounds tested could not support aerobic growth . The fungus was able to ferment carbohydrates consisting of D-glucopyranosyl moieties, grow in the absence of vitamins and in the presence of cycloheximide . It also liquefied gelatin and produced lipases and cellulolytic enzymes . It was found that the highest percentages polyunsaturated fatty acids were produced when acetic acid, glucose, mannitol, soluble starch or trehalose was used as carbon source . The absence of vitamins in the medium lowered the percentage of these fatty acids.

J Dairy Sci, 1997 Mar, 80(3), 530 - 40
The effect of replacing dietary beet pulp with wheat treated with sodium hydroxide, ground wheat, or ground corn in lactating cows; O'Mara FP et al.; This experiment examined the effect of complete diets composed of 60% grass silage and 40% concentrate based mainly on beet pulp, ground wheat, wheat treated with NaOH, or ground corn on milk production and ruminal fermentation of dairy cows . Milk production and fat yield were 19.8, 20.7, 20.1, and 21.2 kg/d and 0.71, 0.76, 0.72, and 0.78 kg/d, respectively (18 cows per treatment) . Cows fed the diet based on ground corn had higher milk production and fat yield, but lower milk protein concentration, than did cows fed the diet based on beet pulp . Cows fed the diet based on ground corn also had higher fat yields than did cows fed the diet based on wheat treated with NaOH . Cows fed the diet based on ground wheat had lower ruminal pH than did cows fed the diet based on beet pulp (6.34 vs . 6.59) and higher ruminal NH3 concentrations (6.2 vs . 5.2 mmol/L) than did cows fed the diet based on ground corn . These results showed little difference in milk production based on wheat processing method and little advantage to replacing beet pulp with either wheat type in a high forage diet . However, milk production and fat yield were increased by replacing beet pulp with ground corn.

J Anim Sci, 1997 Mar, 75(3), 852 - 67
Starch utilization by ruminants: from basics to the bunk; Huntington GB; Starch is the major energy component of grains . Wheat contains 77% of DM as starch, corn and sorghum contain 72%, and barley and oats contain 57 to 58% . In vitro systems have provided valuable data on kinetic aspects of starch digestion . Molecular biological techniques have provided a clearer picture of the ruminal microbial milieu . Proportions of starch fermented in the rumen can be predicted satisfactorily for a variety of grains and processing methods . Compared with dry rolling, steam processing (flaking or rolling) increases ruminal digestibility of starch (percentage of intake) from 52 to 78% for sorghum, from 75 to 85% for corn, and six percentage units or less for other grains . Recent research provides new insight into pancreatic function and intestinal glucose transport systems . The capacity to digest starch in the intestine ranges from 45 to 85% of starch entering the duodenum, with that capacity apparently limited by the supply of pancreatic amylase . There is evidence that amylase secretion may be enhanced by increasing duodenal entry of protein . Capacity for active transport of glucose across of gut wall does not seem to limit the amount of starch digested that is absorbed as glucose . For ruminants eating medium- to high-concentrate diets, about 30% of their total glucose need comes from glucose absorption, 50% from organic acid absorption (substrates for hepatic gluconeogenesis), and 20% from other sources . When glucose absorption from the gut increases, ruminants generally adjust (decrease) gluconeogenesis to meet their need; that need is directly linked to DE intake . In terms of overall ME yield, grain starch is best used when it is fermented in the rumen . However, close coordination of protein and starch supply to the duodenum may improve capture of starch in the form of glucose.

J Bacteriol, 1997 Mar, 179(5), 1505 - 12
Characterization of UDP amino sugars as major phosphocompounds in the hyperthermophilic archaeon Pyrococcus furiosus; Ramakrishnan V et al.; The archaeon Pyrococcus furiosus is a strictly anaerobic heterotroph that grows optimally at 100 degrees C by the fermentation of carbohydrates . It is known to contain high concentrations of novel intracellular solutes such as beta-mannosylglycerate and di-myo-inositol 1,1'-phosphate (DIP) (L . O . Martins and H . Santos, Appl . Environ . Microbiol . 61:3299-3303, 1995) . Here, 31P nuclear magnetic resonance (NMR) spectroscopy was used to show that this organism also accumulates another type of phospho compound, as revealed by a major multiplet signal in the pyrophosphate region . The compounds were purified from cell extracts of P . furiosus by anion-exchange and gel filtration chromatographic procedures and were structurally analyzed by 1H, 13C, and 31P NMR spectroscopy . They were identified as two uridylated amino sugars, UDP N-acetylglucosamine and UDP N-acetylgalactosamine . Unambiguous characterizations and complete assignments of 1H and 13C resonances from such sugars have not been previously reported . In vitro 31P NMR spectroscopic analyses showed that, in contrast to DIP, which is maintained at a constant intracellular concentration (approximately 32 mM) throughout the growth phase of P . furiosus, the UDP amino sugars accumulated (to approximately 14 mM) only during the late log phase . The possible biochemical roles of these compounds in P . furiosus are discussed.

J Chromatogr A, 1997 Feb 28, 763(1-2), 31 - 48
Role of high-performance liquid chromatographic protein analysis in developing fermentation processes for recombinant human growth hormone, relaxin, antibody fragments and lymphotoxin; Jacobson FS et al.; Development of efficient and reliable fermentation processes for protein pharmaceuticals is aided by the availability of accurate quantitative and qualitative product analyses . We have developed a variety of single and dual column chromatographic separations that meet the needs of process development and examples will be provided of how the resulting data has been used to optimize the culture process . For single column methods, reversed-phase chromatography has been the most versatile, permitting the reliable quantitation of many yeast, Chinese hamster ovary (CHO) cell and Escherichia coli-expressed products in the matrix of culture broth or cell extract . Analysis of secreted human growth hormone synthesized in E . coli, along with clipped and unprocessed forms, will be discussed . Another reversed-phase assay for direct analysis of a peptide product (B-chain relaxin) and its degradation products secreted into E . coli fermentation medium has allowed the purification of the responsible protease . Cation-exchange has proven extremely useful for the direct analysis of antibody fragment synthesized in E . coli, allowing the separation and quantitation of the desired Fab' and Fab'2, as well as the unwanted products of glutathione addition and translational read-through . Assay development is often complicated by the presence of host proteins with chromatographic behavior that is similar to that of the product . Commercial instrumentation now permits the facile development of multidimensional chromatographic assays . We show examples of coupled receptor affinity-reversed-phase assays for a mistranslation product and for covalent multimers of E . coli-synthesized lymphotoxin.

J Chromatogr B Biomed Sci Appl, 1997 Feb 21, 689(2), 313 - 20
Assay for the (R)- and (S)-enantiomers of salsolinols in biological samples and foods with ion-pair high-performance liquid chromatography using beta-cyclodextrin as a chiral mobile phase additive; Deng Y et al.; A chromatographic procedure was devised for the quantitative determination of the enantiomers of salsolinol and N-methylsalsolinol, which are biologically important alkaloids . The enantiomers of salsolinol and N-methylsalsolinol were completely separated using beta-cyclodextrin in a reversed-phase ion-pair system . The HPLC method was sensitive enough to detect the isoquinolines at a concentration less than 0.1 pmol per injection . The presence of (R)- and (S)-salsolinol was confirmed in fermented foods and beverages, while N-methylsalsolinol was not detected . On the other hand, the (R)-enantiomers of both salsolinol and N-methylsalsolinol were found to predominate in the human brain.

Brain Res, 1997 Feb 21, 749(1), 71 - 81
Intracerebral administration of Mycoplasma fermentans produces sickness behavior: role of prostaglandins; Yirmiya R et al.; Mycoplasmas are small microorganisms, which cause various diseases in animals and in humans, activate the immune system, and induce the release of various cytokines . Some of the effects of mycoplasmas are mediated by the CNS . Moreover, Mycoplasma fermentans (MF) has recently been found in the brain, as well as other tissues of some AIDS patients, who usually display severe neurobehavioral disturbances . The present study was designed to examine the behavioral effects of central administration of MF, and the role of prostaglandins in mediating these effects . In one set of experiments, rats were injected intracerebroventricularly (i.c.v.) with either saline or a dose of MF (5.1-36 microg per rat), and several behavioral parameters were measured . In addition, body temperature and locomotor activity were continuously monitored by a biotelemetric system . MF induced a significant elevation in body temperature and suppression of motor activity levels . MF also significantly reduced the time spent in social exploration, decreased locomotor and exploratory activity in the open field test, suppressed the consumption of food and saccharine solution, and reduced body weight . In a second set of experiments, i.c.v . administration of MF (7.2 microg) was found to produce a significant increase in the production of prostaglandin E2 (PGE2) in hypothalamic, hippocampal, and cortical tissues . This effect was blocked by indomethacin, a prostaglandin synthesis inhibitor . Indomethacin also attenuated the effects of MF on body temperature, motor activity and body weight, suggesting the involvement of prostaglandins in mediating some of the effects of MF . Together, these findings suggest that the presence of MF in the brain may be responsible for some of the neurobehavioral abnormalities in HIV-infected patients.

J Biol Chem, 1997 Feb 21, 272(8), 4699 - 704
A point mutation in the mitochondrial cytochrome b gene obviates the requirement for the nuclear encoded core protein 2 subunit in the cytochrome bc1 complex in Saccharomyces cerevisiae; di Rago JP et al.; A yeast mutant (cor2-45) in which approximately half of the C terminus of core protein 2 of the cytochrome bc1 complex is lacking due to a frameshift mutation that introduces a stop at codon 197 in the COR2 gene fails to assemble the cytochrome bc1 complex and does not grow on non-fermentable carbon sources that require respiration . The loss of respiration is more severe with this frameshift mutation than with the complete deletion of the COR2 gene, suggesting deleterious effects of the truncated core 2 protein . A search for extragenic suppressors of the nuclear cor2-45 mutation resulted (in addition to the expected nuclear suppressors) in the isolation of a suppressor mutation in the mitochondrial DNA that replaces serine 223 by proline in cytochrome b . Assembly of the cytochrome bc1 complex and the respiratory deficient phenotype of the cor2-45 mutant are restored by the proline for serine replacement in cytochrome b . Surprisingly, this amino acid replacement in cytochrome b corrects not only the phenotype resulting from the cor2-45 frameshift mutation, but it also obviates the need for core protein 2 in the cytochrome bc1 complex since it alleviates the respiratory deficiency resulting from the complete deletion of the COR2 gene . This is the first report of a homoplasmic missense point mutation of the mitochondrial DNA acting as a functional suppressor of a mutation located in a nuclear gene and the first demonstration that the supernumerary core protein 2 subunit is not essential for the electron transfer and energy transducing functions of the mitochondrial cytochrome bc1 complex.

FEMS Microbiol Lett, 1997 Feb 15, 147(2), 273 - 7
Catabolite inactivation of the yeast maltose transporter requires ubiquitin-ligase npi1/rsp5 and ubiquitin-hydrolase npi2/doa4; Lucero P et al.; The maltose transporter in Saccharomyces cerevisiae is degraded in the vacuole after internalization by endocytosis when protein synthesis is impaired and a fermentable substrate is present . The possible implication of the ubiquitin pathway in this inactivation, known as catabolite inactivation, has been investigated . Using mutants deficient in npi1/rsp5 ubiquitin-protein ligase and npi2/doa4 ubiquitin-protein hydrolase, we have shown that these two enzymes are required for normal endocytosis and degradation of the transporter . These facts indicate that the ubiquitin pathway is involved in catabolite inactivation of the maltose transporter . The results also revealed that both enzymes act in the internalization step of endocytosis.

Biol Trace Elem Res, 1997 Feb, 56(2), 203 - 13
Studies on the effects of selenium on rumen microbial fermentation in vitro; Kim J et al.; The effects of selenium (Se) on ruminant microbial fermentation were investigated in vitro using rumen microflora collected from a rumen-fistulated dairy cow . First, the effects of L-selenomethionine (SeMet; at 0.2 or 2 ppm Se) in the presence or absence of wheat bran (WB, 500 mg per incubation flask) were evaluated . Second, the effects of several forms of Se (elemental Se: 50 ppm Se; sodium selenite: 2 ppm Se; SeMet: 2 ppm Se) were compared . Results showed that the amounts of short-chain fatty acids (SCFAs) tended to be increased by SeMet treatment, whereas SeMet in the presence of WB transiently suppressed fermentation . The addition of SeMet tended to increase the production of acetate while reducing the production of butyrate with the without WB supplementation . Among the different Se compounds tested, the amounts of SCFAs were greater with SeMet treatment, which yielded a higher proportion of acetate compared to other treatments . Selenite did not influence the total SCFAs concentrations; however, it increased the relative proportion of butyrate at the expense of acetate . Elemental Se did not significantly affect fermentation . Higher bacterial Se concentrations were observed for selenite than for SeMet . It was concluded that Se supplementation can influence rumen microbial fermentation and that Se compounds differ in this regard.

Br J Nutr, 1997 Feb, 77(2), 243 - 54
Food intake and diet selection in sheep: the effect of manipulating the rates of digestion of carbohydrates and protein of the foods offered as a choice; Kyriazakis I et al.; An experiment was designed to investigate whether the degree of synchrony between the rates of digestion of carbohydrates and N of foods offered as a choice would have an effect, through their consequences, on the short- and long-term diet selection of sheep . Four foods (RL, RH, SL and SH) with the same high metabolizable energy, and similar high metabolizable protein contents were made into pellets . Foods RL and RH were based on a rapidly fermentable carbohydrate source and foods SL and SH on a slowly fermentable carbohydrate source; within each source one food (RL or SL) had a low, and the other (RH or SH) a high, rumen-degradable protein (RDP) content . The foods within a carbohydrate source were offered either singly or as a choice (RL/RH or SL/SH) to eleven rumen-fistulated mature sheep . The design was two 3 x 3 Latin squares (replicated once) with 5-week periods; squares consisted of two single foods and their respective choice . Weeks 1, 3 and 5 were considered to be controls, and weeks 2 and 4 used for rumen infusions of either urea or fructose infused over 4 h (10.00-14.00 hours) . Food intake (FI) and diet selections (DS) were recorded daily and every 2 h (08.00-16.00 hours) on days 2-5 of each week; rumen pH and NH3 concentrations were also measured during these time intervals of day 5 . As expected, feeding treatment affected significantly the rumen measurements: rumen NH3 concentrations were higher on foods RH and SH, and rumen pH lowest on RL . Daily FI was lowest on treatments SL, and choice SL/SH . The mean daily proportion of the low-RDP food in the selected diet was lower when the carbohydrate source was rapidly (choice RL/RH) rather than slowly fermentable (choice SL/SH); this was consistent with the experimental hypothesis . Short-term infusions affected further rumen variables (in the expected directions), irrespective of feeding treatment . However, DS over the 4h infusion period were unaffected; these short-term DS were consistent with the ones selected over the longer term (daily) . The results suggest that the long-term (daily) diet selection of sheep may be affected by the degree of synchrony of energy and protein to the rumen . The fact that diet selections were not altered further by short-term manipulations of these supplies might reflect inadequacies of the methodology (infusions) adopted here.

J Antibiot (Tokyo), 1997 Feb, 50(2), 126 - 34
A family of novel macrocyclic lactones, the saccharocarcins produced by Saccharothrix aerocolonigenes subsp . antibiotica . II . Physico-chemical properties and structure determination; Hegde VR et al.; Six novel tetronic acid analogs were isolated from the fermentation broth of the actinomycete Saccharothrix aerocolongenes subsp . antibiotica SCC1886 . The structures of these saccharocarcins were determined by their spectral data, and chemical degradation . All six compounds are derived from two modified tetronic acid homologs which differ from other tetronic acids by having an ethyl or propyl side chain at C-23 and a methyl group at C-16 . They are all characterized by a novel sugar-amide at C-17.

Biochem Mol Biol Int, 1997 Feb, 41(2), 359 - 66
Ca2+/calmodulin-binding proteins in yeast . Catabolite repression and induction by carbon sources; dos Santos CF et al.; Soluble calmodulin-binding proteins from Saccharomyces carlsbergensis were analyzed in cells grown on glucose, maltose and galactose as carbon source . A large number of polypeptide chains showed affinity for calmodulin by affinity chromatography and overlay techniques . Amongst these, polypeptides of 115, 67 and 45 kDa were only detected during the second exponential phase of growth on glucose or non-fermentative carbon sources, suggesting that they might be subjected to catabolite repression . Polypeptides of 195 and 22 kDa were only observed in cells grown on maltose, whereas 88 kDa polypeptide was only observed in galactose-grown cells . Among the calmodulin -binding polypeptides, eight were phosphorylated in a Ca2+/calmodulin -dependent manner (220, 200, 175, 100, 62, 55, 31 and 16 kDa) . Ca2+/calmodulin dependent {gamma-32P} incorporation was dramatically decreased in yeast cells submitted to a heat treatment.

FEMS Immunol Med Microbiol, 1997 Feb, 17(2), 103 - 9
Mycoplasma fermentans enhances concanavalin A-induced apoptosis of mouse splenic T cells; Shibata K et al.; Mycoplasma fermentans, an AIDS-associated mycoplasma, possessed the activity of enhancing concanavalin A-induced apoptosis of T cells purified from mouse spleen by a nylon wool column, and tumor necrosis factor-alpha played an important role in expression of the activity . M . salivarium, an oral mycoplasma, used for comparative purposes also possessed the activity, the level of which was lower than that of M . fermentans.

Eur J Gastroenterol Hepatol, 1997 Feb, 9(2), 163 - 8
Histological changes in the colonic mucosa following irrigation with short-chain fatty acids; Scheppach W et al.; OBJECTIVES: Short-chain fatty acids (SCFAs) derived from bacterial fermentation of complex carbohydrates are preferred luminal nutrients of the colonic mucosa . Starvation of colonocytes through lack or impaired metabolism of luminal SCFAs may be a cofactor in the pathogenesis of ulcerative colitis . DESIGN: A detailed histological evaluation of colonic biopsy specimens was performed in patients with active distal ulcerative colitis who were treated with rectal enemas containing a mixture of SCFAs, n-butyrate alone or saline placebo . Together with light microscopic parameters of mucosal inflammation, the pattern of crypt cell proliferation (proliferating cell nuclear antigen) and the mucosal activity of factor XIII were assessed . RESULTS: Butyrate reduced the density of polymorphonuclear leucocytes in the lamina propria (4 weeks: P = 0.063; 8 weeks: P = 0.091); other inflammatory parameters remained unchanged . Both butyrate and the SCFA mixture reduced significantly the number of proliferating cells in the upper 40% of crypts . Tissue factor XIII activity in active ulcerative colitis was significantly lower than in mucosa from normal colons; however, it was not affected by SCFA or butyrate irrigation . CONCLUSION: SCFAs and butyrate have a more marked effect on crypt cell proliferation than on parameters of inflammation in patients with active ulcerative colitis.

J Dairy Sci, 1997 Feb, 80(2), 374 - 84
Effect of yeast culture in the diets of early lactation dairy cows on ruminal fermentation and passage of nitrogen fractions and amino acids to the small intestine; Putnam DE et al.; Eight early lactation, primiparous Holstein cows were fitted with ruminal and duodenal cannulas . The cows were used in a replicated 4 x 4 Latin square design to test the effects of yeast culture (0 vs . 10 g/ d) and dietary crude protein (CP) (16.1 vs . 18.8% of dry matter) in 44% forage diets . Dietary CP differed primarily in ruminally degradable CP (9.1 vs . 11.4% of dry matter) . Dry matter intake tended to increase as amount of yeast culture increased . However, yeast culture had no effect on ruminal pH, concentrations of NH3 and volatile fatty acids in ruminal fluid, or ruminal digestibility . Yeast culture increased the ruminal concentration of isobutyrate in cows fed the low CP diet and decreased the concentration of isobutyrate in cows fed the high CP diet . The higher CP diets increased microbial N passage to the duodenum and had no effect on passage of nonmicrobial nonammonia N . Flows to the duodenum of nonmicrobial nonammonia N tended to be higher for cows fed yeast culture . Flows of essential amino acids to the duodenum and the essential amino acid profiles of duodenal digesta and of mixed ruminal bacteria were not altered by yeast culture . Yields of fat and 4% fat-corrected milk were increased by yeast culture supplementation of the low CP diet . Similar tendencies were noted for yields of milk and milk protein.

Steroids, 1997 Feb, 62(2), 253 - 7
Novel reduction and hydroxylation products formed by Aspergillus fumigatus from Reichstein's substance S; Garai S et al.; Fermentation of Reichstein's Substance S with Aspergillus fumigatus (AM-21) under aerobic conditions yielded 17 alpha, 21-dihydroxy-5 alpha-pregn-l-ene-3.20-dione . 17 alpha,20 alpha, 21-trihydroxy-5 alpha-pregn-l-en-3-one . 6 beta,17 alpha, 21-trihydroxypregn-4-en-3,20-dione . 15 beta,17 alpha,21-trihydroxy-5 alpha-pregnane-3,20-dione, and 15 beta, 17 alpha,20 alpha,21-tetrahydroxy-5 alpha-pregn-l-en-3-one . Each microbial metabolite was characterized by spectroscopic methods, including 13C NMR chemical shifts.

J Anim Sci, 1997 Feb, 75(2), 502 - 11
The effects of chemical treatment of whole canola seed on lipid and protein digestion by steers; Aldrich CG et al.; Five Angus x Simmental steers (average BW 259 kg) cannulated in the rumen, proximal duodenum, and terminal ileum were fed five diets in a 5 x 5 Latin square design . Experimental periods were 14 d in length, with 10 d of diet adaptation and 4 d of sample collection . The basal diet contained (percentage of diet DM) ammoniated corn cobs (50%), alfalfa hay (22%), cornstarch grits (13%), corn (6.7%), cane molasses (5%), and urea (1.25%) . Three canola seed-containing diets and a diet containing Ca salts of long-chain fatty acids (Ca-LCFA) were formulated by replacing cornstarch grits from the basal diet with the test feedstuffs . Whole canola seed untreated, crushed, or treated with a caustic alkaline solution and an oxidant were included at 10% of diet DM . The Ca-LCFA diet contained (percentage of diet DM) canola meal (5%) and Megalac (5%) . Diets containing untreated, crushed, and treated canola seed and Ca-LCFA contained, on average, 5.6% more total fatty acids than the basal diet . Steers were fed 5.3 kg DM/d (2.05% of initial BW) in 12 equal portions (every 2 h) . Ruminal fermentation characteristics and digestibilities of OM, GE, N, NDF, and ADF were unaffected (P > .05) by diet . Biohydrogenation of total 18-carbon unsaturated fatty acids was greater (P < .05) for steers fed the crushed canola seed-containing diet (72.0%) than for steers fed the untreated (27.9%) and treated (38.6%) canola seed-containing diets . Digestibility of total 18-carbon fatty acids in the small intestine was greater for steers fed the crushed canola seed (58.9% of duodenal flow) rather than the untreated canola seed (28.4% of duodenal flow) and intermediate for steers fed the treated canola seed (47.0% of duodenal flow) . Chemical treatment of whole canola seed may be a viable method for the postruminal delivery of intestinally available unsaturated fatty acids to ruminants.

Yeast, 1997 Feb, 13(2), 101 - 17
Determination of the relative ploidy in different Saccharomyces cerevisiae strains used for fermentation and 'flor' film ageing of dry sherry-type wines; Guijo S et al.; The full chromosomal karyotype of six enological Saccharomyces cerevisiae strains used for fermentation and biological ageing of sherry-type wines was studied . A genetic method based on the analysis of segregation frequencies of auxotrophic markers, among random spore progeny of hybrids, constructed between laboratory and industrial wine strains (Bakalinsky and Snow, 1990) was used . This method was combined with the analysis of strains by pulsed-field gel electrophoresis . The results obtained clearly indicate the presence of two, three or four copies of a chromosome in the industrial strains examined, and thus confirm that aneuploidy/polyploidy is not uncommon in these strains . In all strains examined, chromosome XIII polysomy is observed . This chromosome contains the ADH2 and ADH3 loci, that code for the ADHII and ADHIII isoenzymes of alcohol dehydrogenase, which are involved in ethanol oxidative utilization during biological ageing of wines . Tetrad analysis for the 'flor formation' character suggest two possibilities: this character is either regulated by at least a digenic system, or by only one gene present on a chromosome which is, at least, disomic.

Int J Food Microbiol, 1997 Feb, 34(2), 187 - 93
Lipolysis of pork fat by the meat starter culture Debaryomyces hansenii at various environmental conditions; Sorensen BB; Lipolysis of pork fat by the meat starter culture Debaryomyces hansenii added at a level of 3.5 x 10(6) cells/ml was investigated at different temperatures (10-30 degrees C), pH values (4.7-6.0) . NaCl concentrations (2.5-7.5% w/v), and times of incubation (5-15 days) . Pronounced growth was obtained amounting to 10(7)-10(9) cells/ml even at conditions combining the lowest temperature, the lowest pH and the highest NaCl concentration . Pork fat was hydrolysed to an extent depending on the environmental conditions . A quadratic polynomial model was developed describing the combined effects of environmental conditions on lipolysis . Regression analysis of data indicated that temperature, pH and time of incubation at conditions of meat fermentation were all significant factors in controlling lipolysis whereas NaCl concentration at the levels studied had no significant effect . Lipolysis increased when temperature increased . At 10 degrees C, lipolysis was very restricted even though growth was observed . An increase in pH resulted in higher lipolysis, the effect being most pronounced at high temperatures.

Ther Drug Monit, 1997 Feb, 19(1), 112 - 6
Determination of rapamycin in whole blood by HPLC; Svensson JO et al.; Sirolimus (rapamycin, RAPA) is a natural fermentation product (macrolide antibiotic) that has demonstrated potent immunosuppressive activity . A reverse-phase high-performance liquid chromatographic (HPLC) method is described for analysis of the drug in whole blood . The samples are purified by using liquid-liquid extraction with butyl chloride/diethyl ether combined with reversed-phase solid-phase extraction . RAPA and internal standard were traced by UV-detection at 278 nm . Linear calibration curves with correlation coefficients > 0.999 were obtained (range, 1-50 ng/ml) . Minimum detectable concentration was approximately 0.4 ng/ml and recovery approximately 45% for both RAPA and internal standard . Coefficient of variation (day to day) was 9.8% at 5 ng/ml (n = 6) and 5.6% at 40 ng/ml (n = 6) . The chromatography requires < 10 min per sample . The assay has proved to be free of interference peaks from cyclosporine or tacrolimus . The method has been used to determine the whole blood concentrations in samples from healthy volunteers and renal transplant recipients receiving single and multiple doses of oral rapamycin.

Appl Environ Microbiol, 1997 Feb, 63(2), 454 - 60
Cloning of genes coding for L-sorbose and L-sorbosone dehydrogenases from Gluconobacter oxydans and microbial production of 2-keto-L-gulonate, a precursor of L-ascorbic acid, in a recombinant G . oxydans strain; Saito Y et al.; We have purified L-sorbose dehydrogenase (SDH) and L-sorbosone dehydrogenase (SNDH) from Gluconobacter oxydans T-100 that showed an ability to convert D-sorbitol to 2-keto-L-gulonate (2-KLGA) . A genomic library of Gluconobacter oxydans T-100 was screened with a probe, a 180-bp PCR product which was obtained from degenerate oligodeoxyribonucleotides based on the elucidated sequence of the purified SDH (used as primers) and the genomic DNA of G . oxydans T-100 (used as a template) . From sequencing of the DNA from a clone positive to the probe, the SNDH and the SDH were estimated to be coded in sequential open reading frames with 1,497 and 1,599 nucleotides, respectively, which was confirmed by expression of the DNA in Escherichia coli that showed both enzymatic activities . The DNA was introduced to a shuttle vector which was prepared from a plasmid of G . oxydans T-100 and pHSG298 to obtain an expression vector designated pSDH155 . The production of 2-KLGA by pSDH155 in G . oxydans G624, an L-sorbose-accumulating strain, was improved to 230% compared to that of G . oxydans T-100 . Chemical mutation of the host strain to suppress the L-idonate pathway and replacement of the original promoter with that of E . coli tufB resulted in improving the production of 2-KLGA . Consequently, high-level production from D-sorbitol to 2-KLGA (130 mg/ml) was achieved by simple fermentation of the recombinant Gluconobacter.

Curr Genet, 1997 Feb, 31(2), 119 - 21
Identification of a Saccharomyces cerevisiae mitochondrial-DNA which can act as a promoter tightly regulated by carbon source when placed in the nucleus; MacIver FH et al.; Screening of a promoter probe gene bank for DNA sequences that could act as inducible promoters following growth on non-fermentable carbon sources led to the identification of the mitochondrially encoded cytochrome oxidase subunit 1 gene (COX1) as an active sequence . Carbon-source regulation of this promoter was confirmed by a beta-galactosidase assay which showed a 31- and 180-fold induction of expression after growth on ethanol or lactate-based media respectively . Two elements matching the CCAAT-binding-factor motif, which is involved in activating transcription on non-fermentable carbon sources, were identified in the putative promoter . Expression was found to be reduced to low levels in otherwise isogenic hap3 and hap4 mutant strains . Thus, this mitochondrial DNA when placed in the nucleus can act as a promoter that is subject to strict carbon-source regulation . These observations are discussed both with respect to the origin of the S . cerevisiae COX1 gene in particular and with respect to the origin of introns in general.

J Bacteriol, 1997 Feb, 179(3), 889 - 98
Hydrogen regulation of growth, growth yields, and methane gene transcription in Methanobacterium thermoautotrophicum deltaH; Morgan RM et al.; Changes in growth rate, methanogenesis, growth yield (Y(CH4)), and methane gene transcription have been correlated with changes in the supply of H2 to Methanobacterium thermoautotrophicum deltaH cells growing on H2 plus CO2 in fed-batch cultures . Under conditions of excess H2, biomass and methanogenesis increased exponentially and in parallel, resulting in cultures with a constant Y(CH4) and transcription of the mth and mrt genes that encode the H2-dependent N5,N10-methenyltetrahydromethanopterin (methenyl-H4MPT) reductase (MTH) and methyl coenzyme M reductase II (MRII), respectively . Reducing the H2 supply, by decreasing the percentage of H2 in the input gas mixture or by reducing the mixing speed of the fermentor impeller, decreased the growth rate and resulted in lower and constant rates of methanogenesis . Under such H2-limited growth conditions, cultures grew with a continuously increasing Y(CH4) and the mtd and mcr genes that encode the reduced coenzyme F420-dependent N5,N10-methenyl-H4MPT reductase (MTD) and methyl coenzyme M reductase I (MRI), respectively, were transcribed . Changes in the kinetics of growth, methanogenesis, and methane gene transcription directed by reducing the H2 supply could be reversed by restoring a high H2 supply . Methane production continued, but at a low and constant rate, and only mcr transcripts could be detected when the H2 supply was reduced to a level insufficient for growth . ftsA transcripts, which encode coenzyme F390 synthetase, were most abundant in cells growing with high H2 availability, consistent with coenzyme F390 synthesis signaling a high exogenous supply of reductant.

Curr Microbiol, 1997 Feb, 34(2), 91 - 6
The Anaerobic Fungus Neocallimastix sp . Strain L2: Growthand Production of (Hemi)Cellulolytic Enzymes on a Range of CarbohydrateSubstrates
Dijkerman R, Ledeboer J, Op den Camp HJM, Prins RA, van der Drift C.
The anaerobic fungus Neocallimastix sp . strain L2,isolated from the feces of a llama, was tested for growth on a range ofsoluble and insoluble carbohydrate substrates . The fungus was able to fermentglucose, cellobiose, fructose, lactose, maltose, sucrose, soluble starch,inulin, filter paper cellulose, and Avicel . No growth was observed onarabinose, galactose, mannose, ribose, xylose, sorbitol, pectin, xylan,glycerol, citrate, soya, and wheat bran . The fermentation products aftergrowth were hydrogen, formate, acetate, ethanol, and lactate . Thefermentation pattern was dependent on the carbon source . In general, higherhydrogen production resulted in decreased formation of lactate and ethanol.Recovery of the fermented carbon in products at the end of growth ranged from50% to 80% . (Hemi)cellulolytic enzyme activities were affectedby the carbon source . Highest activities were found in filtrates fromcultures grown on cellulose . Growing the fungus on inulin and lactose yieldedthe lowest cellulolytic activities . Highest specific activities foravicelase, endoglucanase, beta-glucosidase, and xylanase were obtained withAvicel as the substrate for growth (0.29, 5.9, 0.57, and 13IU · mg-1 protein, respectively) . Endoglucanase activitybanding patterns after SDS-PAGE were very similar for all substrates . Minordifferences indicated that enzyme activities may in part be the result ofsecretion of different sets of isoenzymes.

Mol Gen Genet, 1997 Jan 27, 253(4), 439 - 47
UBI4, the polyubiquitin gene of Saccharomyces cerevisiae, is a heat shock gene that is also subject to catabolite derepression control; Watt R et al.; Carbon and nitrogen regulation of UBI4, the stress-inducible polyubiquitin gene of Saccharomyces cerevisiae, was investigated using a UBI4 promoter-LacZ fusion gene (UBI4-LacZ) . Expression of this gene in cells grown on different media indicated that the UBI4 promoter is more active during growth on respiratory than on fermentable carbon sources but is not subject to appreciable control by nitrogen catabolite repression . UBI4-LacZ expression was virtually identical in cells having constitutively high (ras2, sra1-13) or constitutively low (ras2) levels of cyclic AMP-dependent protein kinase activity, indicating that this kinase does not exert a major influence on UBI4 expression . Catabolite derepression control of the UBI4 promoter was confirmed by measurements of UBI4-LacZ expression in hap mutant and wild-type strains before and after transfer from glucose to lactate . Mutagenesis of the perfect consensus for HAP2/3/4 complex binding at position -542 resulted in considerable reduction of UBI4 promoter derepression with respiratory adaptation in HAP wild-type cells and abolished the reduced UBI4-LacZ derepression normally seen when aerobic cultures of the hap1 mutant are transferred from glucose to lactate . This HAP2/3/4 binding site is therefore a major element contributing to catabolite derepression of the UBI4 promoter, although data obtained with hapl mutant cells indicated that HAP1 also contributes to this derepression . The HAP2/3/4 and HAP1 systems are normally found to activate genes for mitochondrial (respiratory) functions . Their involvement in mediating higher activity of the UBI4 promoter during respiratory growth may reflect the contribution of UBI4 expression to tolerance of oxidative stress.

J Biol Chem, 1997 Jan 10, 272(2), 867 - 74
Tracer studies with crude U-13C-lipid mixtures . Biosynthesis of the lipase inhibitor lipstatin; Eisenreich W et al.; The biosynthesis of the pancreatic lipase inhibitor lipstatin was investigated by fermentation experiments using cultures of Streptomyces toxytricini, which were supplied with soybean oil and a crude mixture of U-13C-lipids obtained from algal biomass cultured with 13CO2 . Lipstatin was analyzed by one- and two-dimensional NMR spectroscopy . 13C total correlation spectroscopy and INADEQUATE experiments show that two fatty acid fragments containing 14 and 8 carbon atoms, respectively, are incorporated en bloc into lipstatin . The 14-carbon fragment is preferentially derived from the unsaturated fatty acid fraction, as shown by an experiment with hydrogenated U-13C-lipid mixture, which is conducive to labeling of the 8-carbon moiety but not of the 14-carbon moiety . The data indicate that the lipstatin molecule can be assembled by Claisen condensation of octanoyl-CoA with 3-hydroxy-delta5,8-tetradecanoyl-CoA obtained by beta oxidation of linoleic acid . The formation of lipstatin from acetate units by a polyketide-type pathway is ruled out conclusively by these data . The data show that surprisingly clear labeling patterns can be obtained in studies with crude, universally 13C-labeled precursor mixtures that are proffered together with a large excess of unlabeled material . One- and two-dimensional 13C total correlation spectroscopy analyses are suggested as elegant methods for the delineation of contiguously 13C-labeled biosynthetic blocks.

Nature, 1997 Jan 9, 385(6612), 151 - 4
Episodic adaptive evolution of primate lysozymes; Messier W et al.; Although the darwinian concept of adaptation was established nearly a century ago, it has been difficult to demonstrate rigorously that the amino-acid differences between homologous proteins from different species have adaptive significance . There are currently two major types of sequence tests for positive darwinian selection on proteins from different species: sequence convergence, and neutral rate violation (reviewed in ref . 1) . Lysozymes from the stomachs of cows and langur monkeys, two mammalian species displaying fermentation in the foregut, are an example of amino-acid sequence convergence among homologous proteins . Here we combine tests of neutral rate violation with reconstruction of ancestral sequences to document an episode of positive selection on the lineage leading to the common ancestor of the foregut-fermenting colobine monkeys . This analysis also detected a previously unsuspected adaptive episode on the lineage leading to the common ancestor of the modern hominoid lysozymes . Both adaptive episodes were followed by episodes of negative selection . Thus this approach can detect adaptive and purifying episodes, and localize them to specific lineages during protein evolution.

Chin J Biotechnol, 1997, 13(1), 17 - 23
Study of mathematical model for product formation with recombinant microbes expressed IFN; Xu J et al.; Based on the known molecular interactions of aporepressor, corepressor, and inducer, a mathematical model of product formation about the Trp operon regulated recombinant microbes has been proposed . The linear relation of the overall transcription rate constant and overall translation rate constant on the specific growth rate has been suggested . We used experimental data where engineered microorganisms express interferon (IFN) . Decay constant of IFN, mRNA transcription rate constant, and IFN expression rate constant have been estimated . An equation related to IFN concentration in fermentation on specific growth rate and Trp concentration has been obtained . By application of the equation, the expression of IFN is calculated based on Trp concentration and specific growth rate in fermentation . Also, the optimum overall culture time can be determined.

Dev Biol Stand, 1997, 90, 245 - 56
Polyvalent vaccines in fish: the interactive effects of multiple antigens; Busch RA; Fermentation and cell-grown products commonly used as fish vaccines present a relatively crude mixture of antigenic and other immunologically active components to the immune system . The specific antigenic make-up and the potential protective immunogenicity of this mixture is dependent upon the strain of the pathogen, production parameters, inactivation methods, down-stream processing, product formulation, storage conditions and the delivery method under which the final product is applied . In the past ten years, commercial vaccine products for fish have more often consisted of mixtures of multiple products, including two, three, four and five vaccines . Such mixtures present an even more extensive and complex array of antigens to the immune system . Considering the fact that not all antigens stimulate a protective immune response, that antigens vary in their immuno-dominance relative to each other and that the immune system of fish has a defined and limited capacity to respond to individual antigenic substances, it becomes increasingly difficult to formulate these complex mixtures into safe and effective commercial products . The clonal capacity of fish to respond to multiple antigens may depend on a variety of factors including host species and age, water temperature, route of administration and temporal considerations . There is growing evidence that antigenic as well as non-antigenic components of vaccines can interact synergistically or antagonistically and that they can stimulate, cross-react with, inhibit or even suppress the immune response to specific antigens . This paper reviews current knowledge about the interactive effects of antigenic components of fish vaccines and gives specific examples of how these interactions might affect the formulation and performance of multivalent products . This paper also considers the potential basis for these interactive effects and discusses technical approaches that take advantage of this knowledge for the development of new multivalent products.

Dev Biol Stand, 1997, 90, 191 - 9
Immunization with viral antigens: infectious pancreatic necrosis; Christie KE; Clinical IPN has traditionally been observed in brook trout (Salvelinus fontinalis) and rainbow trout (Oncorhynchus mykiss) . However, during the past 10 years outbreaks of IPN have been reported frequently in farmed Atlantic salmon (Salmo salar L.) in Norway . Acute IPN with high mortality is observed in fry at start feeding and in smolt in the first six months after transfer to seawater . Today IPN is the most important infectious disease in Norway in farmed fish, giving economic losses of about 60 million USD yearly . A prophylactic strategy against this disease is strongly needed . Different strategies for developing IPN vaccines have been tested since the virus was first isolated in 1960 . Vaccination with live virus has not been successful and is probably not an acceptable strategy for environmental risk reasons . Vaccination with inactivated virus has been tested in rainbow trout given by the oral route, by immersion and injection . Protection against challenge was obtained only by injection . IPN vaccines based on inactivated virus may be effective but are expensive . A subunit vaccine produced by fermentation is a more realistic strategy for fish vaccine production if the actual protective epitopes can be identified . Protective IPNV epitopes may include both B- and T-cell epitopes, but only B-cell epitopes have been examined so far . Epitope mapping with neutralising monoclonal antibodies indicates that the internal variable region of VP2 (aa 200-350) folds into an immunodominant structure including both serotype specific and conserved neutralisation epitopes that can renaturate spontaneously from E . coli-expressed recombinant VP2 (rVP2) . Analysis with an IPNV group-A specific neutralising monoclonal antibody indicates that immunisation with recombinant protein containing the segment (aa 86-210) might induce protection against all IPNV serotypes . Subunit vaccines based on E . coli-expressed IPNV proteins have been tested in rainbow trout and Atlantic salmon . Vaccination by immersion in rainbow trout fry with bacterial lysate from E . coli expressing the IPNV Sp strain gene segment A induced protection against challenge with the IPNV Buhl strain . By injection of Atlantic salmon parr with partly purified E . coli-expressed rVP2 (N1 strain), increased resistance against IPN infection was demonstrated by challenge . In field trials it is shown that vaccination of pre-smolt with rVP2 included in a commercial oil/glucan adjuvanted multivalent bacterial vaccine gives protection against IPN in natural outbreaks, compared to fish vaccinated with the same vaccine without the IPNV component.

Skin Pharmacol, 1997, 10(2), 63 - 70
A skin equivalent model for cosmetological trials: an in vitro efficacy study of a new biopeptide; Augustin C et al.; The European Community directive, imposing that effects claimed for cosmetic actives must be validated using non-animal procedures, has stimulated the use of in vitro models for pharmacotoxicological trials . In this paper, an efficacy study of a new biopeptide, a hydrolysate obtained by fermentation of milk proteins, was performed using an in vitro skin equivalent (SE) . This SE is obtained by seeding normal human keratinocytes onto a dermal equivalent comprising a collagen-glycosaminoglycan(GAG)-chitosan porous matrix populated by normal human fibroblasts, which neosynthesize their own extracellular matrix (ECM) . A gel containing 2% milk biopeptide was applied topically (10 microliters) every 2 days during 15 days . Subsequent investigations of the biopeptide effects were based on morphological criteria after histological analysis and on synthesis of ECM components . Collagen and GAG synthesis were measured by tritiated proline, glucosamine and Na2(35)SO4 incorporation . Qualitatively, the histological features of the biopeptide-treated SEs showed a thicker epidermis than the untreated control SEs, where only a few layers of stratum corneum were observed . The dermal porous matrix seems to be more filled by neosynthesized ECM than the control . Quantitatively, milk biopeptide treatment induced a significant activation of hyaluronic acid (+46%) and sulfated GAG (+53%) synthesis, whereas only non-significant increases of total protein and collagen synthesis were observed (Student's test, p < 0.001).

Biosens Bioelectron, 1997, 12(6), 521 - 9
Multianalyte biosensors on optical imaging bundles; Healey BG et al.; We present an optical biosensor design that expands the utility of enzyme biosensors . These biosensors are fabricated by site-selective photodeposition of analyte-sensitive polymer matrices on optical imaging fibres . These dual-analyte arrays allow for the simultaneous, independent measurement of the analyte of interest and the transducing analyte . The first integrated optical-biosensors using this design have been prepared that allow both the dependent and independent analytes to be measured simultaneously, for example penicillin and pH (Healey & Walt, 1995) or glucose and O2 (Li & Walt, 1995) . Independent measurement of the transducing analyte allows penicillin or glucose to be quantitated in the presence of a concurrent pH or O2 change, respectively . Penicillin can be measured in the range 0.25-10.0 mM in the pH range 6.2-7.5 . Glucose can be measured in the range 0.6-20.0 mM in the O2 range 20-100% . The utility of the sensor design was demonstrated by using the penicillin-dual-analyte biosensor to quantitate penicillin produced during a Penicillium chrysogenum fermentation.

Microbiol Immunol, 1997, 41(6), 445 - 52
Unification of the genera Serpulina and Brachyspira, and proposals of Brachyspira hyodysenteriae Comb . Nov., Brachyspira innocens Comb . Nov . and Brachyspira pilosicoli Comb . Nov; Ochiai S et al.; The phylogenetic positions of Serpulina hyodysenteriae, Serpulina innocens, Serpulina pilosicoli and Brachyspira aalborgi were studied . Complete 16S ribosomal DNA sequences of these three species and B . aalborgi revealed that their 16S rDNA sequences were related more than 96.0% . The mol% guanine plus cytosine (G+C) of B . aalborgi DNA was 27.1, and was similar to those of the 3 members of the genus Serpulina . The homologous rates using 31P-labeled B . aalborgi chromosome DNA in DNA-DNA reassociation tests were 22.0% to S . hyodysenteriae, 19.1% to S . innocens and 17.2% to S . pilosicoli . Therefore, we propose to transfer the three species of the genus Serpulina to the genus Brachyspira . Descriptions of Brachyspira hyodysenteriae comb . nov., Brachyspira innocens comb . nov . and Brachyspira pilosicoli comb . nov., and an emended description of B . aalborgi are given . Phenotypic characteristics of the 4 members of the genus Brachyspira were also studied . They fermented fructose, galactose, glucose, lactose, maltose, mannose, raffinose and trehalose; however, B . aalborgi did not ferment raffinose . All of them hydrolyzed esculin but did not produce indole except for B . hyodysenteriae . The protein profile of B . aalborgi was different from those of the four strains of B . hyodysenteriae, B . innocens and B . pilosicoli, but the heavy bands with molecular sizes of 49.4 and 52.3 kDa of B . aalborgi were quite similar to those of B . innocens in the points of quantity and molecular size . In immunoblotting tests, B . aalborgi reacted well with anti-B . innocens and B . pilosicoli sera, but reacted weakly with anti-B . hyodysenteriae serum . Only one heavy band and several faint bands were revealed by the reaction between B . aalborgi and anti-B . hyodysenteriae serum, and the heavy band was common among these strains.

Folia Microbiol (Praha), 1997, 42(3), 214 - 8
Fed-batch cultivation of bakers' yeast: effect of nutrient depletion and heat stress on cell composition; Ertugay N et al.; The physiology of a commercial strain of bakers' yeast was studied in terms of the cell composition under different growth conditions and of its response to stress . The study comprised fed-batch experiments since this is the system used in bakers' yeast industry . The classical fed-batch fermentation procedure was modified in that the yeast cells were continuously grown to a steady-state at a dilution rate of 0.1/h in order to achieve more or less the same initial starting point in terms of cell composition . This steady-state culture was then switched to fed-batch concomitantly with exposure to stress . The highest amount of trehalose accumulation was achieved when nutrient depletion and heat stress were applied concomitantly . The highest amount of trehalose, 12%, was attained in cells stressed by both nitrogen depletion and heat stress . The protein content remained constant, although with some oscillations, at a value of 30% throughout this dual stress experiment.

Stomatologiia (Mosk), 1997, 76(3), 5 - 11
{The nature of the action of chemical substances on the activity of the microflora in soft dental deposits}; Leont'ev VK et al.; Effects of the principal mineral and mineralizing components of the saliva, nutrient organic acids (carbohydrate and some others substances' metabolites) on the activity of microflora of soft dental deposit were studied in vitro . The inhibitory effect was assessed visually from the appearance or absence of deposit coating, pH measurement, and by photo- and nephelometry . Concentrations of lactic acid and sucrose were measured . The inactivating effects of the reagents were assessed by double control: qualitative, by comparing the specimen with the optic density of the extract from aqueous suspension of the deposit, and time control, by comparing the specimen with the optic density of extracts from deposit suspensions directly after mixing with the medium . Acid medium was found to block the formation of soft dental deposit and inhibit the production of lactic acid by bacterial deposit . Hence, weakly acid gargle is recommended as an effective and physiological measure preventing cariogenic situation resultant from the intake of easily fermenting carbohydrates.

Pol Arch Med Wewn, 1997 Jan, 97(1), 52 - 5
{Accidental poisoning with silo gas}; Jablonska M et al.; Eight cases of poisoning in workers cleaning silo are presented . Silo gas, produced during fermentation of vegetable material, contains very toxic nitrogen oxides . In this group three workers died within silo, four patients were hospitalized (one of them with acute toxic pulmonary oedema, two with sings of pneumonia, one had only transient decrease of consciousness) and recovered without detectable sequelae . One patient, in general good condition, refused hospitalization and recovered.

Int J Cancer, 1997, Suppl 10, 7 - 9
Diet and stomach cancer in Korea; Ahn YO; Stomach cancer is the most prevalent malignant neoplasm in Korea . As of 1991-1992 in Seoul, the cumulative rates reported for the age span 0-74 were 7.6% in males and 3.1% in females . A recent case-control study reported that several food items and cooking methods are associated with increased or decreased risk of stomach cancer among Koreans . An increased risk of stomach cancer was noted among people who frequently consume broiled meats and fishes, salted side dishes (salted/fermented fish products) and salty stewed foods, such as soybean paste thick stew . Frequent consumption of mung bean pancake, tofu, cabbage, spinach and sesame oil decreased the risk . Analysis by cooking method showed that risk of stomach cancer from the same foods varied with preparation . For meat and fish, pan frying was associated with decreased risk, whereas stewing or broiling was associated with increased risk . Pickled vegetables increased the risk, whereas fresh vegetables did not . In a recent cohort study in Seoul, green vegetables and soybean foods were associated with a decreased risk of stomach cancer . Case-control and cohort studies have reported that ginseng intake decreased the risk of gastric cancer.

J Toxicol Clin Toxicol, 1997, 35(4), 395 - 9
Tacrolimus (FK 506) overdose: a report of five cases; Mrvos R et al.; INTRODUCTION: Tacrolimus (FK 506), a potent anti-T cell agent, has been shown to be effective in preventing the rejection of transplanted organs . Published research on tacrolimus has focused on effects associated with therapeutic use . Virtually no literature addresses the acute toxicity or the management of tacrolimus overdose . We report five cases of acute overdose with tacrolimus . CASE REPORTS: A 2-year-old female with no prior medical history ingested 10 mg of tacrolimus . She remained asymptomatic . A 2-year-old female with a history of multiple visceral organ transplants ingested 11 mg of her tacrolimus . She was admitted to the hospital and activated charcoal was administered . Her renal function was monitored and no changes were noted in a 24 h period . She was discharged . A 29-year-old male renal transplant patient took 150 mg of tacrolimus . He recovered with only a minimal creatinine elevation . A 23-year-old heart and lung transplant patient ingested 375 mg of tacrolimus . She had no effects from the overdose . A 34-year-old female experienced an acute/chronic overdose of 7-9 mg and remained asymptomatic . DISCUSSION: Tacrolimus is a neutral macrolide antibiotic that is extracted from the fermentation broth of the soil fungus Streptomyces tsukubaensis . Chronic oral dosing has been associated with numerous side effects . Although these patients ingested significant doses of tacrolimus, they suffered few toxic manifestations associated with tacrolimus . CONCLUSION: Little information is available regarding acute tacrolimus overdosage . In this small series of patients, tacrolimus did not produce acute physiologic incapacitation.

Scand J Infect Dis, 1997, 29(2), 195 - 6
Isolation of dysgonic fermenter 3, a rare isolate associated with diarrhoea in immunocompromised patients; Melhus A; CDC group DF-3 is a rare isolate from blood, stools and wounds . During the last few years attention to this bacterium has increased due to its association with diarrhoea and bacteremia in immunocompromised patients . This report presents an isolation of this bacterium from a decubitus ulcer of a subfebrile patient with diarrhoea.

Life Sci, 1997, 60(22), 1987 - 94
Cardiovascular effects of the fungal extract of basidiomycetes sp . YL8006; Andreacchi AS et al.; Many fungal products are known to possess biological activity towards the mammalian tissues . We studied vasodilating activity in the crude ethanol extract of the dried mycelia of Basidiomycetes sp . YL8006, cultured by submerged fermentation with a complex medium . The activity was assayed using the isolated perfused rat heart in the working mode . Immediately following injection of the extract into the perfusion system, a 20-25% increase in coronary flow was observed (p<0.001 vs . solvent vehicle control) . There was a concurrent decrease in diastolic pressure and coronary vascular resistance . Aortic flow, systolic pressure, and cardiac output declined slightly over time after treatment . No significant changes in heart rate, efficiency, and oxygen consumption were observed . Solvent vehicle did not cause any changes in hemodynamic performance.

Reprod Nutr Dev, 1997, 37(2), 173 - 89
Quantitative review of ruminal and total tract digestion of mixed diet organic matter and carbohydrates; Archimede H et al.; The mean response and main factors of variation (level of concentrate, nature of carbohydrate in the concentrate and level of intake) for organic matter, cell wall material, starch digestion and microbial synthesis in the gastrointestinal tract of ruminants were quantitatively reviewed using a data base involving 157 papers . The ruminal digestion (mean +/- SE%) of organic matter, cell wall material, and starch were 45.2 +/- 11.2 (n = 553), 47.7 +/- 17.7 (n = 348), and 74.1 +/- 16.2 (n = 140), respectively and the proportion of each component digested in the rumen in relation to total tract digestibility was 64.7 +/- 12.3, 78.8 +/- 18.5 and 80.5 +/- 16.3, respectively . The efficiency of microbial synthesis (g of microbial protein/kg of organic matter truly fermented in the rumen) and the proportion of microbial nitrogen in the total amount of nitrogen leaving the stomachs (%) were, 23.6 +/- 9.3 (n = 320) and 55.1 +/- 16.5 (n = 289), respectively . The ruminal digestion of organic matter increased by 2 points for every 10 percent increase in concentrate incorporation . The ruminal digestion of cell wall material was maximal when the concentrate incorporation in the diet was 30% . When the ruminal digestion of cell wall decreased, the substitution of ruminal digestion by intestinal digestion was partial (10%) . The efficiency of microbial synthesis was optimal when the level of concentrate incorporation was 40% . The nature of the carbohydrates in the concentrates had a significant effect on the efficiency of the microbial synthesis, which was higher (+6.6 g of nitrogen/kg of fermentable organic matter in the rumen) with slowly degradable starch (SS) or digestible fiber (DF) than with rapidly degradable starch (RS) . Moreover, the mean depression of cellulolysis in the rumen was higher with RS (-13 points) comparatively to SS (-7 points) or DF (-5 points).

Mikrobiol Z, 1997 Jan-Feb, 59(1), 31 - 6
{The modification of the internucleotide relations of antisignature oligodeoxyribonucleotides as a means of increasing their resistance to nuclease cleavage in mollicute cells}; Egorov OV; Modifications in 5'- and 3'-ends and internucleotide bondings of antisignature oligodesoxyribonucleotides have been studied for their resistance to nuclease cleavage in cells of Acholeplasma laidlawii PG-8 and Mycoplasma fermentans PG-18 . It is shown that adding of benzylamide grouping to the 5'-end of oligonucleotides increases their half-life period in the studied mollicute cells to 15 h . S-methyl modification of 3'-end of antisignature oligonucleotides did not take essential effect on the process of degradation of the given compounds in the mollicute cells . Considerable increase of stability in the studied cels of thio- and dithiophosphate analogues of oligodesoxyribonucleotides has been detected.

Vestn Khir Im I I Grek, 1997, 156(1), 76 - 9
{The dynamics of the enzyme system indices in the blood serum of patients with acute ischemia of the extremities}; Kariakin AM et al.; The article presents an analysis of investigations performed for determining activity of certain enzymatic systems in the general and regional blood flow in 55 patients with the syndrome of acute ischemia of the upper and lower extremities caused by embolism and arterial thrombosis . The dynamics of fermentemia depending on the degree of ischemia and adequacy of restoration of the blood circulation in the extremity involved was established . The levels of CK, LDH, AST and ALT in the blood serum of patients with regional ischemia was shown to be of great prognostic value.

Gut, 1997 Jan, 40(1), 49 - 56
Alcoholic beverages produced by alcoholic fermentation but not by distillation are powerful stimulants of gastric acid secretion in humans; Teyssen S et al.; BACKGROUND: The effect of commonly ingested alcoholic beverages on gastric acid output and release of gastrin in humans is unknown . AIM AND METHODS: In 16 healthy humans the effect of some commonly ingested alcoholic beverages produced by fermentation plus distillation (for example, whisky, cognac, calvados, armagnac, and rum) or by alcoholic fermentation (beer, wine, champagne, martini, and sherry) on gastric acid output and release of gastrin was studied . Gastric acid output was determined by the method of intragastric titration . Plasma gastrin was measured using a specific radioimmunoassay . RESULTS: None of the alcoholic beverages produced by fermentation plus distillation had any significant effect on gastric acid output and release of gastrin compared with control (isotonic glucose and distilled water) . Alcoholic beverages produced only by fermentation significantly (p < 0.05) increased the gastric acid output by 57% to 95% of maximal acid output (MAO) and release of gastrin up to 5.1-fold compared with control . If beer, wine, and sherry were distilled, only their remaining parts increased gastric acid output by 53% to 76% of MAO and increased release of gastrin up to 4.3-fold compared with control . CONCLUSIONS: (1) Alcoholic beverages produced by fermentation but not by distillation are powerful stimulants of gastric acid output and release of gastrin; (2) the alcoholic beverage constituents that stimulate gastric acid output and release of gastrin are most probably produced during the process of fermentation and removed during the following process of distillation.

Planta, 1997, 201(4), 496 - 501
Nitrate reductase activation state in barley roots in relation to the energy and carbohydrate status; Botrel A et al.; The NADH-dependent nitrate reductase (NR, EC 1.6.6.1) in roots of hydroponically grown barley seedlings was extracted, desalted and the activity measured in buffer containing either Mg2+ (10 mM) or EDTA (5 mM) . The former gives the actual NR activity (NRact) equivalent to dephospho-NR, whereas the latter gives the maximum NR capacity of the dephospho-form (NRmax) . Both values together permit an estimation of the NR-phosphorylation state . Changes in NRact and NRmax were followed in response to root aeration or to shoot illumination or shoot removal, and were correlated with sugar contents and adenylate levels . Ethanol formation was also measured in roots differing in NR activity in order to obtain information on the relation between anaerobic alcoholic fermentation and nitrate reduction . In aerated roots, NR was highly phosphorylated (about 80%) and largely inactive . It was partly dephosphorylated (activated) by anoxia or by cellular acidification (pH 4.8 plus propionic acid) . Anaerobic activation (dephosphorylation) of NR was stronger at acidic external pH (5) than at slightly alkaline pH (8), although ATP levels decreased and AMP levels increased at pH 5 and at pH 8 to the same extent . Thus, rapid changes in the NR-phosphorylation state in response to anaerobiosis were not directly triggered by the adenylate pool, but rather by cytosolic pH . Under prolonged darkness (24 h) or after shoot removal . NRmax decreased slowly without a large change in the phosphorylation state . This decrease of NRmax was correlated with a large decrease in the sugar content, and was prevented by glucose feeding, which had only minor effects on the phosphorylation state . Cycloheximide also prevented the decrease in NRmax without affecting the phosphorylation state . In contrast, anaerobiosis or cellular acidification prevented the decrease of NRmax and at the same time decreased the NR-phosphorylation state . It is suggested that NR turnover in roots is controlled by several factors: NR synthesis appears to depend on sugar availability, which has little effect on the phosphorylation state; in addition, NR degradation appears to be strongly affected by the phosphorylation state in such a way that the inactive phospho-NR is a better substrate for NR degradation than the dephospho-form . The rate of anaerobic ethanol formation was not affected by NR activity, indicating that the purpose of NR activation under hypoxia or anoxia is not to decrease or prevent alcoholic fermentation.

Scand J Gastroenterol Suppl, 1997, 222, 58 - 61
Effects of short-chain fatty acids on gastrointestinal motility; Cherbut C et al.; Besides their action on gut morphology and function, short-chain fatty acids (SCFAs), produced by bacterial fermentation of carbohydrates in the colon, influence gastrointestinal motility . As they are not present in the stomach and proximal small intestine, SCFAs do not directly affect motility of these segments . However, caecal infusion of SCFAs as well as colonic fermentation of lactulose induce a relaxation of the proximal stomach in humans, indicating that SCFAs can affect motility at a distance from their site of production . Moreover, this suggests that SCFAs may be involved in the so-called "ileocolonic brake', i.e . the inhibition of gastric emptying by nutrients reaching the ileo-colonic junction . In the terminal ileum, where their concentration may increase following a colo-ileal reflux, SCFAs stimulate contractions and shorten ileal emptying, which may protect ileal mucosa against the potentially harmful effects of the reflux of colonic contents . Although SCFAs are produced and concentrated in the colon, their action on motility of this organ is not clearly understood and may depend on concentration, molecular structure of the acids, responsiveness of the colonic segments and animal species . The mechanisms of action of SCFAs on gastrointestinal motility are not completely elucidated . They may involve systemic humoral and neural pathways as well as local reflexes and myogenic responses.

Scand J Gastroenterol Suppl, 1997, 222, 25 - 7
Germ-free and conventional animal models for intestinal carbohydrate disposition; Midtvedt T; Under conventional (CONV) conditions, the microbial flora is capable of breaking down most dietary derived carbohydrates as well as complex carbohydrates (glycolipids, glycoproteins, etc.) from the host . The major end products of these processes are short-chain fatty acids (SCFAs) . In non-ruminants, most of the fermentation takes place in the large bowel . In ruminants, however, most acids are formed more proximal in the gastrointestinal (GI) tract . These microbial derived products may influence upon many host related functions, locally in the GI tract as well as elsewhere in the body . In germ-free (GF) animals, neglectable amounts of SCFAs are found in faeces . Parallel studies in GF and CONV animals given a standardized diet and ex-GF animals, receiving the same diet and mono/poly-associated with known microbial species, represent excellent models for answering such questions as (i) what can the microbes do? and (ii) what have the microbes done? These models allow detailed studies of the complex interplay between the host, his diet and his GI flora.

Scand J Gastroenterol Suppl, 1997, 222, 3 - 9
Human colonic microbiota: ecology, physiology and metabolic potential of intestinal bacteria; Macfarlane GT et al.; In both health and disease, the colonic microbiota plays an important role in several areas of human physiology . This complex assemblage of microorganisms endows great metabolic potential on the large intestine, primarily through its degradative abilities . Many hundreds of different types of bacteria, varying widely in physiology and biochemistry, exist in a multitude of different microhabitats in the lumen of the large gut, the mucin layer and on mucosal surfaces . Both microbiota and host obtain clear benefits from association . For example, growth substrates from diet and body tissues, together with a relatively stable environment for bacteria to proliferate are provided by the host, which in turn has evolved to use butyrate, a bacterial fermentation product, as its principal source of energy for epithelial cells in the distal bowel . The main sources of carbon and energy for intestinal bacteria are complex carbohydrates (starches, non-starch polysaccharides) . Carbohydrate metabolism is of great importance in the large intestine, since generically, and in terms of absolute numbers, the vast majority of culturable microorganisms are saccharolytic . The amounts and types of fermentation products formed by colonic bacteria depend on the relative amounts of each substrate available, their chemical structures and compositions, as well as the fermentation strategies (biochemical characteristics and catabolite regulatory mechanisms) of bacteria participating in depolymerization and fermentation of the substrates . Protein breakdown and dissimilatory amino acid metabolism result in the formation of a number of putatively toxic metabolites, including phenols, indoles and amines . Production of these substances is inhibited or repressed in many intestinal microorganisms by a fermentable source of carbohydrate . Owing to the anatomy and physiology of the colon, putrefactive processes become quantitatively more important in the distal bowel, where carbohydrate is more limiting.

Alcohol Alcohol, 1997 Jan-Feb, 32(1), 23 - 31
Action of ethanol and some alcoholic beverages on gastric acid secretion in anaesthetized rats; Teyssen S et al.; The action of intragastric ethanol in various concentrations equivalent to those found in alcoholic beverages (1.5-40 v/v), ethanol 96% (v/v) and of some commonly ingested alcoholic beverages produced by alcoholic fermentation (beer, wine, champagne, martini and sherry) or by fermentation plus distillation (e.g . whisky, cognac, calvados, armagnac and rum) on gastric acid output (GAO) was studied in anaesthetized Wistar rats . Ethanol concentrations of 1.5%, 4% and 10% v/v did not significantly alter basal GAO, whereas all higher concentrations of ethanol (20%, 40% and 96% v/v) significantly (P < 0.05) and dose-dependently decreased the GAO . All alcoholic beverages produced by fermentation significantly increased GAO by 30-35% of maximal acid output (MAO; 48 micrograms/kg pentagastrin intramuscularly), whereas alcoholic beverages produced by fermentation plus distillation significantly decreased GAO as compared to control (isotonic glucose and distilled water) . Glucose solutions to which yeast was added, resulting in fermentation, were as potent stimuli of GAO as beer . Lyophilized fermented glucose at different concentrations (dilution of 1:20 to 1:1) dose-dependently stimulated GAO: the highest dilution (1:20) had no effect, the 1:5 dilution significantly increased gastric acid secretion similarly to that of beer and fermented glucose . The highest concentration of lyophilized fermented glucose (1:1) was as potent as the MAO after pentagastrin (90% of MAO) . In conclusion, the present investigation shows for the first time that, in rats: (1) ethanol in a concentration > 10% v/v inhibits GAO; (2) lower ethanol concentrations (< 10% v/v) do not alter GAO; (3) alcoholic beverages produced by fermentation but not those produced by alcoholic fermentation plus distillation are powerful stimulants of GAO; (4) the stimulatory non-alcoholic ingredients of these alcoholic beverages are most likely produced during the process of fermentation of carbohydrates and removed during the following process of distillation.

Nutr Health, 1997, 11(3), 139 - 47
Probiotic fermentation: effect on antinutrients and digestibility of starch and protein of indigenously developed food mixture; Binita R et al.; An indigenously developed food mixture which contained huskless barley flour, green gram dhal flour, skimmed milk powder and tomato pulp ("BGMT" mixture) was autoclaved, cooled and fermented with L . acidophilus at 37 degrees C for 24 h at a dosage of 100,000 cells/ml . This process markedly reduced the phytic acid and polyphenol content and significantly improved the in vitro digestibility of starch and protein . Starch digestibility almost doubled in the fermented mixture . A significant negative relationship was obtained between the contents of antinutrients and digestibility.

Nat Toxins, 1997, 5(2), 86 - 9
Toxin-producing species of Penicillium and the development of mycotoxins in must and homemade wine; Moller T et al.; A number of penicillium strains belonging to the species Penicillium roqueforti, P . crustosum, P . paneum Frisvad, and P . chrysogenum were analyzed for their ability to produce the mycotoxins isofumigaclavine A, isofumigaclavine B, festuclavine, roquefortine C, and PR toxin when cultured on three different media . Some of the strongest mycotoxin-producing strains were later inoculated into samples of must (grape juice) before and after wine fermentation . After incubation at 25 degrees C for 1 and 2 weeks it was found that all except one of the penicillium strains were able to produce one or more of the toxins analyzed . However, the types of toxins as well as toxin concentrations varied a great deal, depending on culturing medium or culturing time . The media containing yeast extract normally gave higher toxin levels . From the wine experiments it was shown that isofumigaclavine A can be formed under certain circumstances in must and wine . A qualitative High Performance Liquid Chromatography (HPLC) method for simultaneous determination of isofumigaclavines A and B, roquefortine C, and PR toxin was also developed.

Nutr Cancer, 1997, 27(2), 143 - 9
Type of dietary fiber, not fat, alters phospholipase D and ornithine decarboxylase activities in the rat large intestine; Horvath PJ et al.; We investigated the effect of dietary fatty acid composition (n-6 vs . n-3) and fiber (highly fermentable vs . less fermentable) on the activities of phospholipase D (PLD) and ornithine decarboxylase (ODC) in the rat large intestine (cecum and proximal and distal colon) . Twenty-four Sprague-Dawley rats (215-270 g) ate synthetic diets with 2% safflower oil plus 21.5% safflower or fish oil and 10% cellulose or guar gum for four weeks . Cecal bile acids and free fatty acids were higher in rats fed guar gum than in rats fed cellulose . Rats fed fish oil had more proximal colonic mucosal and cecal bile acids than those fed safflower oil . PLD activity was 23% lower in the proximal colon of rats fed guar gum than in those fed cellulose, but the mucosal weight was not different . ODC activity was lower but cecal mucosal wet weight was higher in the cecum of the rats fed guar gum than in the cecum of the rats fed cellulose . The activities of PLD and ODC are affected by dietary fiber and may not be accurate markers for tissue growth in the colonic mucosa.

J Dairy Sci, 1997 Jan, 80(1), 160 - 6
A blend of animal and cereal protein or fish meal as partial replacement for soybean meal in the diets of lactating Holstein cows; Polan CE et al.; Six replications in Experiment 1 and four replications in Experiment 2 of a 3 x 3 Latin square arrangement of treatments were used to compare soybean meal or soybean meal partially replaced with fish meal or a protein blend for response in intake, milk yield and composition, ruminal NH3 N, blood urea, and ruminal fermentation in lactating Holstein cows . The blend contained 30% corn gluten meal, 30% poultry by-products, 30% blood meal, and 10% feather meal . Periods were 28 d, and the first 7 d were used for adjustment . In addition to these protein sources, diets contained corn silage, alfalfa haylage, dried cracked corn, ground barley plus added fat, and a mineral and vitamin mixture . In Experiment 1, mean DMI was 24.4 kg, mean milk yield was 36.7 kg, mean fat percentage was 3.48%, and mean milk protein percentage was 3.06%; there were no significant differences . In Experiment 2, DMI was different for soybeans (22.6 kg) versus other sources (21.4 kg), but milk yield (32.1 kg) and fat (3.39%) and protein (2.87%) percentages did not differ among diets . In Experiment 1, ruminal NH3 N was greatest for cows consuming soybean diets (11.0 mg/dl) and lowest for cows consuming diets containing the protein blend (8.7 mg/dl) . No differences in VFA were found . The lack of response to RUP can be explained by a rather high intake of a fermentable diet, which supplied sufficient absorbable AA according to the Cornell AA model.

J Dairy Sci, 1997 Jan, 80(1), 152 - 9
Effects of supplemental fat and protein source on ruminal fermentation and nutrient flow to the duodenum in dairy cows; Chan SC et al.; Four lactating Holstein cows, fitted with ruminal and T-type duodenal cannulas, were used in a 4 x 4 Latin square design for four periods (14 d each) . Treatments were 1) medium fat and low quality protein, 2) medium fat and high quality protein, 3) high fat and low quality protein, and 4) high fat and high quality protein . Fat was supplemented by addition of 2.5% prilled fatty acids to high fat diets . The low quality diets contained corn gluten meal and 0.47% Lys, and the high quality diets contained a mixture of fish, blood, and soybean meals and 0.77% Lys . The percentage of Met was similar for all diets (mean, 0.28%) . Diets contained 35 to 38% steam-flaked sorghum and 32% chopped alfalfa hay . Dietary CP averaged 18%, and all diets were high in RUP (44% of CP) . Yields of milk, milk protein, and SNF were increased by added fat and by high quality protein . Ruminal NH3 and butyrate were increased by supplemental fat . Cows fed high quality protein had increased ruminal VFA, propionate, butyrate, and valerate, but decreased ratios of acetate to propionate . Essential AA concentrations in coccygeal plasma and arteriovenous differences across the mammary gland were higher for Lys and lower for Leu in cows fed high quality protein than in those fed low quality protein.

Cytotechnology, 1997, 23(1-3), 103 - 11
Monitoring proteolysis of recombinant human interferon-gamma during batch culture of Chinese hamster ovary cells; Goldman MH et al.; Proteolytic cleavage of recombinant human interferon-gamma (IFN-gamma) expressed in Chinese hamster ovary (CHO) cells during batch fermentation has been monitored by mass spectrometric peptide mapping . IFN-gamma was purified from cell-free culture supernatant by immunoaffinity chromatography and cleaved by endoprotease Asp-N . Peptide fragments were resolved by reverse-phase HPLC and identified by a combination of matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) and automated N-terminal peptide sequencing . Using this approach, a peptide was identified as the C-terminal fragment of the IFN-gamma polypeptide . Analysis of this peptide by MS indicated that the recombinant IFN-gamma polypeptide secreted by CHO cells was truncated by at least ten amino acids, initially at Gln133-Met134 . No full length (143 amino acids) polypeptide molecules were observed at any stages of the fermentation . Additional proteolytic cleavages at basic amino acids N-terminal of Gln133 occurred during the later stages of the culture resulting in a heterogeneous IFN-gamma polypeptide with "ragged" C-termini.

Dtsch Tierarztl Wochenschr, 1997 Jan, 104(1), 17 - 22
{Effect of moldy grass on intraluminal fermentation and thiamine metabolism in cattle (in vitro)}; Holtershinken M et al.; The influence of mouldy grass (kind of moulds: Fusarium sp., Epicoccum oryzae, Ulocladium spp., Mucor spp.) on the in-vitro-fermentation especially the thiamine-metabolism of bovine rumen fluid was investigated using the longterm rumen simulation technique (RUSITEC) . Four investigation periods keeping 23 days each were carried out . After a control period of nine days (normal hay) an eight days lasting testphase followed . During this time two reaction vessels (KF) were charged with normal hay, two vessels (VF II) with mouldy grass and two (VF I) with a 50:50-mixture of normal hay and mouldy grass . During the last five days of the testperiod 0.3 mg thiamine/reaction vessel were added daily . In the last six days all reaction vessels were fed with normal hay . The following effects of mouldy grass during the investigation period on the rumen fluid and rumen gas, respectively, could be noted: changes of short volatile fatty acids concentrations (acetate -9.9% {p < 0.05} propionate up to -12.2% {ns}, i-butyrate up to +39.9% {p < 0.001}, n-butyrate up to +25% {p < 0.01}); increase of ammonia concentrations up to 68% (p < 0.01); small increase of pH for 0.08 units (p < 0.01); decrease of the methane production up to 16.6% (p < 0.001); increase of thiamine input due to the mouldy grass up to 310% (p < 0.05); increased breakdown of substituted thiamine for 44%.

J Ind Microbiol Biotechnol, 1997 Jan, 18(1), 43 - 8
Automated fed-batch fermentation with feed-back controls based on dissolved oxygen (DO) and pH for production of DNA vaccines; Chen W et al.; A fermentation process in Escherichia coli for production of supercoiled plasmid DNA for use as a DNA vaccine was developed using an automated feed-back control nutrient feeding strategy based on dissolved oxygen (DO) and pH . The process was further automated through a computer-aided data processing system to regulate the cell growth rate by controlling interactively both the nutrient feed rate and agitation speed based on DO . The process increased the total yield of the plasmid DNA by approximately 10-fold as compared to a manual fed-batch culture . The final cell yield from the automated process reached 60 g L-1 of dry cell weight (OD600 = 120) within 24 h . A plasmid DNA yield of 100 mg L-1 (1.7 mg g-1 cell weight) was achieved by using an alkaline cell lysis method . Plasmid yield was confirmed using High Performance Liquid Chromatography (HPLC) analysis . Because cells had been grown under carbon-limiting conditions in the automated process, acetic acid production was minimal (below 0.01 g L-1) throughout the fed-batch stage . In contrast, in the manual process, an acid accumulation rate as high as 0.36 g L-1 was observed, presumably due to the high nutrient feed rates used to maintain a maximum growth rate . The manual fed-batch process produced a low cell density averaging 10-12 g L-1 (OD600 = 25-30) and plasmid yields of 5-8 mg L-1 (approximately 0.7 mg g-1 cells) . The improved plasmid DNA yields in the DO- and pH-based feed-back controlled process were assumed to be a result of a combination of increased cell density, reduced growth rate (mu) from 0.69 h-1 to 0.13 h-1 and the carbon/nitrogen limitation in the fed-batch stage . The DO- and pH-based feed-back control, fed-batch process has proven itself to be advantageous in regulating cell growth rate to achieve both high cell density and plasmid yield without having to use pure oxygen . The process was reproducible in triplicate fermentations at both 7-L and 80-L scales.

J Ind Microbiol Biotechnol, 1997 Jan, 18(1), 18 - 21
Comparison of industrial yeast strains for fermentation of spent sulphite pulping liquor fortified with wood hydrolysate; Smith MT et al.; Ethanol production from spent sulphite pulping liquor (SSL) was compared for four different yeasts . A second strain of S . cerevisiae as well as a 2-deoxyglucose-resistant strain formed through protoplast fusions between S . uvarum and S . diastaticus produced up to 27% more ethanol from SSL fortified with hydrolysis sugars than was produced by S . cerevisiae . The incremental improvement in ethanol yield appeared to vary with the degree of fortification, ranging from 5.8% for unfortified SSL, to 27% for the highest level of fortification tested . Decreasing fermentation rates were observed for SSL fortified with glucose, mannose and galactose, respectively . Sugar uptake rates in SSL fortified with glucose, galactose and mannose were 6.8, 2.8 and 2.0 g L-1 h-1, respectively . However, when these sugars were fermented along with a glucose cosubstrate, the rate at which the combined glucose/mannose medium was fermented was nearly identical to that of the glucose control.

J Antibiot (Tokyo), 1997 Jan, 50(1), 58 - 65
Chloropeptins, new anti-HIV antibiotics inhibiting gp120-CD4 binding from Streptomyces sp . I . Taxonomy, fermentation, isolation, and physico-chemical properties and biological activities; Tanaka H et al.; Chloropeptins I and II, which are gp120-CD4 binding inhibitors, were isolated as pale yellow-brown powders from the mycelia of a soil actinomycete, Streptomyces sp, WK-3419 . Their physico-chemical properties showed that they are chlorinated peptides . Chloropeptin I (C61H45N7O15Cl6) is a novel compound, but chloropeptin II was identified as complestatin . Both compounds inhibited gp120-CD4 binding (IC50: 1.3 and 2.0 microM, respectively), the cytopathic effect of HIV in MT-4 cells (EC50: 1.6 and 1.7 microM, respectively) and syncytium formation in co-cultured HIV-1-infected and uninfected MOLT-4 cells (IC50 . 0.5 and 1.1 microM, respectively) . Chloropeptin I was synergistic in the inhibition of the cytopathic effect when combined with other anti-HIV drugs such as zidovudine (AZT), didanosine (ddI), zalcitabine (ddC) and nevirapine.

J Antibiot (Tokyo), 1997 Jan, 50(1), 27 - 31
Cloning of the enomycin structural gene from Streptomyces mauvecolor and production of recombinant enomycin in Escherichia coli; Takeuchi S et al.; A genomic DNA library from the enomycin (ENM) producer, Streptomyces mauvecolor, was screened for the ENM structural gene (enm) by use of a segment of the phenomycin gene (phm) as the probe, and a plasmid, pENI, was constructed . By primer-walking along the insert, a 573 bp DNA sequence that contain an ORF corresponding to preENM was determined . The deduced amino acid composition of ENM was close to that previously reported (MIZUNO, S.; K . NITTA & H . UMEZAWA: Mode of action of enomycin, an antitumor antibiotic of high molecular weight . I . Inhibition of protein synthesis . J . Biochem . 61: 373 approximately 381, 1967) . The producer cells expressed enm during an ENM-productive fermentation . An enm-expression plasmid, pENE 1, was constructed, with which E . coli AD202 was transformed . The transformant produced a fusion protein consisting of glutathione-S-transferase (GST) and ENM . The genetically engineered ENM (rENM) inhibited the growth of Hela cells in vitro . Comparison of the base sequence spanning enm with that spanning phm showed that the structural genes were conserved more extensively than were the flanking regions, though the genes were unlikely to be essential to the lives of the producers.

J Antibiot (Tokyo), 1997 Jan, 50(1), 1 - 7
CP-225,917 and CP-263,114, novel Ras farnesylation inhibitors from an unidentified fungus . I . Taxonomy, fermentation, isolation, and biochemical properties; Dabrah TT et al.; During the course of our screening for squalene synthase inhibitors and Ras farnesylation inhibitors, a novel fungal culture was discovered to produce two structurally unique compounds, CP-225,917 and CP-263,114, as well as zaragozic acid A (squalestatin I) . The two compounds are characterized by a bicyclo{4.3.1}dec-1,6-diene core plus two extended alkyl chains . CP-225,917 and CP-263,114 inhibit Ras farnesyl transferase from rat brain with IC50 values of 6 microM and 20 microM, respectively . CP-225,917 inhibits squalene synthase with an IC50 value of 43 microM and CP-263,114 with an IC50 of 160 microM . The producing organism, though not fully classified, exhibits the characteristics of a sterile Phoma species.

Food Addit Contam, 1997 Jan, 14(1), 89 - 94
Ethyl carbamate levels resulting from azodicarbonamide use in bread; Canas BJ et al.; Azodicarbonamide (ADA), a dough conditioner, is an additive approved in the US up to a maximum of 45 mg/kg in flour . The addition of 45 mg/kg of ADA was investigated and found to increase the ethyl carbamate (EC) content of commercially prepared breads by 1-3 micrograms/kg . A similar increase in EC was observed in breads baked in the laboratory with a bread machine . The increase in EC levels appears to depend on a variety of factors, most notably the concentration of ADA added and the time of fermentation . The addition of 20 mg/kg ADA caused only a slight increase, if any, in commercial products but a 2.3 micrograms/kg increase of EC in breads baked with a bread machine . When 100 mg/kg of ascorbic acid was added along with ADA, smaller EC increases were observed . Addition of urea was also found to enhance the EC content of the bread . Toasting, which was previously shown to increase EC levels, caused even larger increases when ADA or urea had been added.

Carcinogenesis, 1997 Jan, 18(1), 229 - 32
Bcl-2 deregulation leads to inhibition of sodium butyrate-induced apoptosis in human colorectal carcinoma cells; Mandal M et al.; Epidemiological studies have linked dietary fiber to the prevention of human colorectal cancer and suggest that short chain fatty acids such as butyric acid, which is produced by fermentation of dietary fiber in the large intestine, may be an important mediator of the protective effects of fiber . We investigated the role of Bcl-2 deregulation on the sensitivity of colorectal carcinoma cells to undergo butyrate-induced apoptosis . Here we report an inverse relationship between the levels of Bcl-2 and the sensitivity of colorectal carcinoma cell lines to undergo apoptosis in response to butyrate . Overexpression of Bcl-2 in colorectal carcinoma DiFi cells resulted in suppression of butyrate-induced apoptosis and enhanced cell survival in response to butyrate . Butyrate-induced apoptosis was accompanied by inhibition of expression of a 30 kDa protein (p30, immunorecognized by anti-Bcl-2 mAb) and this cellular effect of butyrate was inhibited by Bcl-2 overexpression . These findings suggest that deregulation of Bcl-2 in human colorectal carcinoma cells confers resistance to induction of apoptosis by butyrate, a dietary micronutrient.

Mol Microbiol, 1997 Jan, 23(2), 303 - 12
Stationary-phase regulation of the Saccharomyces cerevisiae SOD2 gene is dependent on additive effects of HAP2/3/4/5- and STRE-binding elements; Flattery-O'Brien JA et al.; SOD2, encoding manganese superoxide dismutase (MnSOD), is essential for stationary-phase survival of yeast cells . In addition, stationary-phase cells are more resistant to oxidative stress than exponential-phase cells . The use of a SOD2::lacZ fusion construct in this study shows that transcription of SOD2 increases 6.5-fold as cells enter stationary phase in rich, glucose medium . The increase in SOD2 expression appears to be due to two phenomena-the switch to a non-fermentable carbon source and nutrient limitation . Analysis of SOD2 transcription in mutant Saccharomyces cerevisiae strains showed that the gene was negatively regulated by intracellular cAMP levels which decrease as cells enter stationary phase . Mutation of 'stress-responsive' (STRE) elements in the SOD2 promoter which respond to cAMP levels resulted in the loss of cAMP-dependent expression but only partially reduced the increase in expression as cells entered stationary phase . A putative Yap1p-binding site was found to be inactive and mutation of YAP1 had no effect on the STRE-mediated expression . To fully eliminate the stationary-phase response, it was necessary to mutate a HAP2/3/4/5 complex binding site in addition to the STRE elements . It is postulated that the effects of the STRE sites and the HAP2/3/4/5 complex binding site are additive.

Biotechnol Prog, 1997 Jan-Feb, 13(1), 1 - 7
Adenine quantitation in yeast extracts and fermentation media and its relationship to protein expression and cell growth in adenine auxotrophs of Saccharomyces cerevisiae; VanDusen WJ et al.; We have described a method to reliably measure the free adenine content of yeast extract powders or the adenine concentrations found in chemically-defined and complex fermentation samples . This method relies on the selective precolumn derivatization of adenine with chloroacetaldehyde to form the fluorescent adenine adduct 1,N6-ethenoadenine . The derivatized adenine can then be resolved from other components found in samples with reverse phase HPLC and selectively monitored with fluorescence . This method was then used to study the adenine nutritional requirements of adenine auxotrophs of recombinant Saccharomyces cerevisiae . The adenine content of individual yeast extract powders was examined in relation to the cell mass (dry cell weight, DCW) achieved in culture media formulated with these powders . A general increase in DCW was observed with increasing adenine concentration in the yeast extract . Conversely, we observed that as adenine concentration increased in complex media the expression levels of a heterologous protein decreased . This method also allowed us to examine the adenine/DCW ratio in both steady-state continuous culture and batch culture . In both cases, the total in vivo adenine content as measured by the amount of adenine utilized from the culture media was estimated to be ca . 25-40 mg/g DCW . However, data suggest that this value is in excess of what is strictly required for cell growth and represents the quantity of adenine required to saturate intracellular pools of adenine or adenine metabolites . A minimum requirement for cell growth is at least as low as 12.5 mg of adenine/g of cells.

Yale J Biol Med, 1996 Jan-Feb, 69(1), 81 - 4
The influence of food, beverages and NSAIDs on gastric acid secretion and mucosal integrity; Peterson WL; Gastric acid secretion is stimulated by all foods, especially proteins, and many beverages, the most potent beverages are milk and fermented substances such as beer and wine . The effects of food on mucosal integrity have been little studied, whereas non-steroidal anti-inflammatory drugs are well known to induce tissue injury.

J Nutr, 1997 Jan, 127(1), 108 - 16
Energy values of non-starch polysaccharides: comparative studies in humans and rats; Wisker E et al.; Energy values of non-starch polysaccharides (NSP) were estimated from NSP fermentability and from digestible energy balances in human subjects and in rats . During four studies, humans consumed four low fiber control diets and six high fiber diets . For the rat diets, duplicates of the foods consumed by humans were mixed together, freeze-dried and ground . Calculated from fermentability, partial digestible energy values of NSP in humans and rats, respectively, were 8.2 +/- 1.3 and 5.7 +/- 1.2 (P = 0.0013, fruits and vegetables), 11.4 +/- 0.7 and 5.7 +/- 3.2 (P = 0.0001, citrus fiber), 5.0 +/- 2.1 and 2.2 +/- 3.3 (P = 0.0429, barley fiber at high protein intake), 4.4 +/- 1.8 and 2.4 +/- 2.0 (P = 0.0561, barley fiber at low protein intake), 6.7 +/- 1.4 and 7.6 +/- 1.2 (P = 0.296, coarse whole meal rye bread), and 7.1 +/- 0.6 and 6.1 +/- 1.7 (P = 0.157, fine whole meal rye bread) kJ/g NSP . Calculated from energy balances, partial digestible energy values of NSP in humans and rats, respectively, were 2.1 +/- 3.5 and -5.0 +/- 4.0 (P = 0.026, fruits and vegetables), 10.7 +/- 5.1 and 1.4 +/- 5.6 (P = 0.003, citrus fiber), 1.6 +/- 5.1 and -17.8 +/- 8.6 (P = 0.0001, barley fiber at high protein intake), -2.6 +/- 4.9 and -9.3 +/- 8.2 (P = 0.044, barley fiber at low protein intake), -3.0 +/- 7.0 and 0.9 +/- 2.5 (P = 0.27, coarse whole meal rye bread), and 0.9 +/- 5.1 and 0.6 +/- 3.7 (P = 0.89, fine whole meal rye bread) kJ/g NSP . Net energy values were 70% of digestible energy values . Differences between species were significant for NSP in fruits and vegetables, citrus fiber, and barley fiber at high protein intake . Most energy values calculated from energy balances were significantly lower than values calculated from NSP fermentation, with differences being greater in rats than in humans . Thus, the energy values of some types of NSP contained in mixed diets could not be estimated accurately from NSP fermentability either in humans or rats . In addition, our results suggest that the rat is not always a suitable model of humans for predicting energy values of NSP in mixed diets.

Pharm Res, 1997 Jan, 14(1), 103 - 7
The use of scintigraphy to provide "proof of concept" for novel polysaccharide preparations designed for colonic drug delivery; Adkin DA et al.; PURPOSE: The aim of the present study was to provide "proof of concept" data in man for novel polysaccharide preparations designed for colonic drug delivery using gamma scintigraphy . METHODS: Two placebo calcium pectinate matrix tablet formulations were studied: one contained calcium pectinate and pectin (CaP/P) and was designed to rapidly disintegrate in the ascending colon, the other contained calcium pectinate and guar gum (CaP/GG) and was designed to disintegrate more slowly, releasing its contents throughout the ascending and transverse colon . Both formulations were enteric coated in order to protect them from the stomach . Ten healthy volunteers received either a CaP/P or CaP/GG tablet, in a randomised cross-over study . Transit and disintegration of the radiolabelled formulations was followed by gamma scintigraphy . Rat studies were conducted in order to verify that the expected colonic degradation of the polysaccharide formulations was as a consequence of bacterial enzyme attack . RESULTS: The in vivo clinical study confirmed the results obtained in the rat and bench in vitro fermentation models; complete tablet disintegration for Formulation CaP/GG appeared to be slower than that of Formulation CaP/P and the time and the location of complete tablet disintegration was more reproducible with Formulation CaP/P compared to Formulation CaP/GG . CONCLUSIONS: These results provide "proof of concept" data for the use of calcium pectinate preparations for drug delivery to the colon and highlight the value of scintigraphy in focusing the development strategy for colonic targeting preparations.

J Recept Signal Transduct Res, 1997 Jan-May, 17(1-3), 115 - 26
Expression of ligand-gated ion channels with the Semliki Forest virus expression system; Lundstrom K et al.; Two types of ligand-gated ion channels were expressed with the Semliki Forest virus (SFV) expression system . The cDNAs for mouse serotonin 5-HT3 receptor and rat and human purinoreceptor P2x subtypes were introduced into the pSFV1 vector . In vitro transcribed RNAs were coelectroporated with pSFV-Helper2 RNA into BHK cells, where in vivo packaging resulted in high titer SFV-5-HT3 and SFV-P2x virus stocks . Infection of BHK, CHO and RIN cells resulted in high-level expression of recombinant receptors . Saturation binding analysis indicated the presence of more than 3 x 10(6) 5-HT3 receptors per cell . Binding studies on isolated membranes yielded from 10 to 60 pmol of either 5-HT3 or P2x receptor per mg protein . Functional responses to the P2x receptors were demonstrated in SFV-infected CHO cells by Ca2+ mobilization or by 45Ca2+ influx . High amplitude electrophysiological responses were also detected for both SFV-5-HT3 and SFV-P2x infected CHO cells in whole-cell patch clamp recordings . To facilitate the purification procedure of SFV-expressed recombinant receptors a histidine tag was introduced at the C-terminus of the 5-HT3 receptor . This 5-HT3His receptor showed high levels of expression, specific binding and high amplitude electrophysiological responses . For large scale expression the BHK cells were adapted to suspension culture and were efficiently infected in a 11.5 liter fermentor culture with SFV-5-HT3His resulting in high-level expression, 52 pmol receptor per mg protein corresponding to 3.2 x 10(6) receptors per cell.

J Anim Sci, 1997 Jan, 75(1), 224 - 9
Effect of forage quality and monensin on the ruminal fermentation of fistulated cows fed continuously at a constant intake; Lana RP et al.; A ruminal fermentation study was used to investigate the relationship between forage quality and monensin-dependent amino acid-sparing . Two fistulated cows were fed three concentrations of chopped (2.5 to 5.0 cm in length) timothy and alfalfa hays (100:0, 50:50 and 0:100) and two levels of monensin (0 and 350 mg.cow-1.d-1) . The diets were offered 12 times per day (9 kg of DM/d), and the rumen reached a steady-state, reducing animal and day variation . Alfalfa hay had 1.4 times more CP and 1.4 times less NDF than timothy hay, and the substitution of timothy with alfalfa increased (P < .05) ruminal ammonia . Monensin had no effect on total ruminal ammonia when timothy hay was present in the diet, and it increased total ruminal ammonia with the 100% alfalfa diet . Effects on ruminal ammonia were, however, confounded by monensin-dependent decreases in ruminal pH (P < .05) . Dissociated ammonia, the species most likely to be adsorbed from the rumen, declined when monensin was added to the 100% timothy diet (P < .05) . Monensin had no effect on dissociated ammonia if alfalfa was 50% or 100% of the forage, but it counteracted alfalfa-dependent decreases in bacterial protein (P < .05) . The idea that monensin could spare amino acids was supported by the observation that monensin decreased (P < .001) the specific activity of deanimation and increased bacterial protein at all combinations of alfalfa and timothy . Increases in bacterial protein could be explained by monensin-dependent increases in total VFA.

J Anim Sci, 1997 Jan, 75(1), 37 - 43
Evaluation of corn and sorghum distillers byproducts; Lodge SL et al.; Two trials were conducted to determine the feeding value of sorghum distillers byproducts . Trial 1, a finishing trial, used 160 yearling steers (327 kg) . Treatments consisted of dry-rolled corn (DRC) control, sorghum wet distillers grains (SWDG), sorghum wet distillers grains plus solubles (SWDGS), and sorghum dried distillers grain plus solubles (SDDGS) . Distillers byproducts were fed at 40% of the diet DM . Cattle fed diets containing SWDG, SWDGS, or DRC were similar in efficiency of gain (P > .10); cattle fed SDDGS were less efficient (P < .10) than all other treatments . Sorghum wet distillers grains, SWDGS, and SDDGS contained 96, 102, and 80% relative NEg of corn, respectively . In Trial 2, 16 crossbred lambs (55 kg) were used to determine the digestibility of sorghum and corn distillers byproducts . Byproducts were fed at 80% of the diet DM and treatments consisted of corn wet distillers grains (CWDG), corn dried distillers grains plus solubles (CDDGS), SWDG, and SDDGS . Neutral detergent fiber digestibility was not different among treatments (P > .10) . Corn wet distillers grains were higher in true nitrogen (P < .001), apparent nitrogen (P < .01), and organic matter digestibility (P < .05) than SWDG . Wet distillers byproducts were higher (P < .01) in apparent organic matter and nitrogen digestibility than dried distillers byproducts . Digestibility of distillers byproducts and subsequent energy values are influenced by type of grain used in the fermentation process and drying of the finished byproduct.

Microbiology, 1997 Jan, 143 ( Pt 1), 187 - 95
The ldhA gene encoding the fermentative lactate dehydrogenase of Escherichia coli; Bunch PK et al.; Under anaerobic conditions, especially at low pH, Escherichia coli converts pyruvate to D-lactate by means of an NADH-linked lactate dehydrogenase (LDH) . This LDH is present in substantial basal levels under all conditions but increases approximately 10-fold at low pH . The ldhA gene, encoding the fermentative lactate dehydrogenase of E . coli, was cloned using lambda 10E6 of the Kohara collection as the source of DNA . The IdhA gene was subcloned on a 2.8 kb MluI-MluI fragment into a multicopy vector and the region encompassing the gene was sequenced . The IdhA gene of E . coli was highly homologous to genes for other D-lactate-specific dehydrogenases but unrelated to those for the L-lactate-specific enzymes . We constructed a disrupted derivative of the ldhA gene by inserting a kanamycin resistance cassette into the unique KpnI site within the coding region . When transferred to the chromosome, the ldhA::Kan construct abolished the synthesis of the D-LDH completely . When present in high copy number, the ldhA gene was greatly overexpressed, suggesting escape from negative regulation . Cells expressing high levels of the D-LDH grew very poorly, especially in minimal medium . This poor growth was largely counteracted by supplementation with high alanine or pyruvate concentrations, suggesting that excess LDH converts the pyruvate pool to lactate, thus creating a shortage of 3-carbon metabolic intermediates . Using an ldhA-cat gene fusion construct we isolated mutants which no longer showed pH-dependent regulation of the ldhA gene . Some of these appeared to be in the pta gene, which encodes phosphotransacetylase, suggesting the possible involvement of acetyl phosphate in ldhA regulation.

Lett Appl Microbiol, 1997 Jan, 24(1), 37 - 9
The effect of temperature on the growth of strains of Kloeckera apiculata and Saccharomyces cerevisiae in apple juice fermentation; Bilbao A et al.; The influence of temperature (10 degrees C and 25 degrees C) on the survival and growth of Saccharomyces cerevisiae and Kloeckera apiculata was examined in mixed and pure cultures during fermentation in apple juice . The growth reached by S . cerevisiae did not seem to be affected by temperature and the presence of K . apiculata . However, the growth and survival of K . apiculata, both in single and mixed cultures, were substantially enhanced at 10 degrees C . The highest amount of ethyl acetate was produced by K . apiculata in pure culture at 10 degrees C . Nevertheless, this concentration was lowest when both yeasts were fermented together at 10 degrees C and 25 degrees C.

Adv Biochem Eng Biotechnol, 1997, 55, 179 - 220
Special transformation processes using fungal spores and immobilized cells; Larroche C et al.; Although many microbial processes have been described which are able to produce interesting aroma compounds, the number of industrial applications are limited . Reasons for this are in most cases low final product yield, low biotransformation rates, substrates and/or end-products inhibition, toxicity towards the microorganisms themselves and difficulties of recovery from the bioreaction mixture . This means that the development of specific catalysts and processes is an important challenge for researchers in this field . This review presents two special kinds of catalysts, fungal spores and immobilized cells, with emphasis on their production and on their use in the production of aroma compounds . The production of fungal spores by solid state fermentation is described in greater detail . In the second part, this review also offers examples of development of three production processes, the production of methyl ketones of spores of Penicillium roquefortii, the hydroxylation of beta-ionone by immobilized Aspergillus niger cells, and the production of alkyl pyrazines by bacteria in liquid and solid media . For each of these processes, the analysis of limiting steps-biological and/or physico-chemical-is presented and the significant role of process conditions to increase aroma yield is discussed.

J Nat Prod, 1997 Jan, 60(1), 33 - 5
Oxysporidinone: a novel, antifungal N-methyl-4-hydroxy-2-pyridone from Fusarium oxysporum; Breinhold J et al.; Oxysporidinone (1), a novel 3,5-disubstituted N-methyl-4-hydroxy-2-pyridone, was isolated from fermentations of Fusarium oxysporum (CBS 330.95) by counter-current chromatography . The structure was determined by spectroscopic methods including NMR, MS, IR, and UV analysis . Oxysporidinone exhibited growth inhibitory activity against several common plant pathogenic fungi.

J Nat Prod, 1997 Jan, 60(1), 6 - 8
Cochliobolic acid, a novel metabolite produced by Cochliobolus lunatus, inhibits binding of TGF-alpha to the EGF receptor in a SPA assay; Robinson N et al.; Cochliobolic acid (1), a novel biologically active natural product, is produced by submerged fermentation of Cochliobolus lunatus . Compound 1 was determined to be a novel polyketide possessing a substituted tetrahydrofuran ring, a conjugated polyene chain and a 1,2-diketone moiety, by interpretation of NMR, MS, and UV/vis spectroscopic data . Compound 1 inhibits the binding of TGF-alpha to the EGF receptor of the human epidermal cell line A431 in a SPA assay with an IC50 of 1.6 microM.

Artif Organs, 1997 Jan, 21(1), 43 - 9
The physiological property and function of the electrolyzed-ionized calcium Aquamax on water molecular clusters fractionization; Hatto M et al.; Aquamax, the ionized mineral (Ca, 21 mg/ml; MG, 0.068 mg/ml; Na 0.13 mg/ml; K, 0.006 mg/ml) is a fermented organic mineral extract . The fundamental physiological property and function of this mineral is to promote the molecular level mineral supply to the cell inside . The contained minerals exist at a molecular level to fractionize the molecular clusters of water and to make water's penetration ratio into objects higher only at 0.1-0.2% concentration . Existing minerals, especially the calcium, were barely dissolved in water, and its low penetration was caused by its low electrolyzed behavior plus the effects from an anion mineral, such as phosphorous, sulfur, nitrogen, or any oxalic acid combining with a colloidal calcium to construct and crystallize as the calcium phosphate and the calcium sulfate . Aquamax minerals penetrate into objects to fractionize water molecular clusters and to make water functional, neutralize in the anion mineral and oxalic acid elements, raise the object's electric conductivity, and preserve perishables.

What Is Genome?, What Is Protein?, What Is Fermentation?, What Is Rhizobia?, What Is Cell Biology?, n, Microbes, s, Bacteria, n, Bacteriology, e, Microorganism, c, Bacterium, c, Corynebacter, s, Streptococcal, o, Bacillus, r, Yeasts, o, Candida albicans, o, Agrobacterium, e, S. cerevisiae, c, Escherichia coli, a, Prokaryotes, s, Growth media, n, Antimicrobials, s, Nitrosomonas, e, Propionibacteria, s, Multidrug resistant, i, Proteus, o, Gram negative, a, Microbial, s, Cell cultures, s, Vancomycin, r, Staphylococcus, c, Microorganisms

Scientific Publications - Work Done by Microbiology Reader Bioscreen C
Agricultural Microbiology Anaerobic Microbiology Antimicrobial Susceptibility Artificial Atmosphere Bioassay of Antibiotics Biofilm Microbiology Bioreactor Technology Biotechnology Cell Biology Clinical Microbiology Environmental Microbiology Experiments with Yeast	Fermentation Food Microbiology Functional Genomics Gene Technology Growth Media Development Growth Rate and Lag Time Industrial Microbiology Medical/Pharmaceutical Field Microbiological Assay Microbiological Research Microbiology of Cosmetics go to a specific theme...	Military Microbiology Molecular Microbiology Mutagenicity and Genotoxicity Oral Microbiology Patents Postantibiotic Studies Soil Microbiology Spore Microbiology Veterinary Microbiology Waste/Wastewater Treatment Water Microbiology Wine Microbiology

� 2005 Transgalactic Ltd (manufacturer of Bioscreen C software) | Privacy Statement | P.O. Box 1393, 00101 Helsinki, Finland, phone: +358 9 85172920, fax: +358 9 8749481, e-mail: microbiology@bionewsonline.com

Last modified: May 25, 2005