Fermentations

J Anim Sci, 1993 Apr, 71(4), 1041 - 6
Modeling gas production kinetics of grass silages incubated with buffered ruminal fluid; Beuvink JM et al.; Time course measurements of in vitro gas production of feedstuffs incubated with buffered ruminal fluid give information about the rate at which the feed is fermented . To compare gas production kinetics from different feeds, a mathematical model was needed to describe the data . We investigated several existing models (exponential, logistic, Gompertz, Richards, Schnute), fitting them to 50 gas production curves obtained with grass silages . None of them gave a satisfactory description of the data . A new model was developed (modified Gompertz model; mGom) that basically divided gas production into two fractions, one arising from rapidly fermentable feed components and the other from slowly fermentable feed components . Residual mean squares (RMS) for the mGom model were lower (P < .05; n = 50) than the RMS for the other models . A good statistical comparison of kinetic gas production data is made possible with the mGom model.

Am J Respir Cell Mol Biol, 1993 Apr, 8(4), 358 - 64
Enhanced secretion of immune-modulating cytokines by human lung fibroblasts during in vitro infection with Mycoplasma fermentans; Fabisiak JP et al.; Fibroblasts may play an important role in the modulation of immune and inflammatory responses through elaboration of cytokines . To test this hypothesis, human lung fibroblasts were isolated from transbronchial biopsy specimens and assayed for production of interleukin-6 (IL-6) and granulocyte/macrophage colony-stimulating factor (GM-CSF) . The sources of fibroblasts included lung allografts, recipient lungs obtained at time of transplant, and normal lung tissue removed during tumor resection . During the course of these studies, several early-passage fibroblasts from transplant recipients were observed to contain mycoplasma (MP)-like organisms as detected by extranuclear fluorescent staining with Hoechst 33258 . Positive staining cultures were associated with isolation of Mycoplasma fermentans . IL-6 and GM-GSF as measured by ELISA were found to be elevated over 50-fold in conditioned medium from MP-infected fibroblasts as compared with noninfected lines . Treatment of cells with mycoplasma removal agent (MRA) eliminated extranuclear Hoechst fluorescence and significantly reduced the production of these cytokines . Tumor necrosis factor-beta (TNF-beta) induction of IL-6 and GM-CSF was amplified synergistically in infected cultures . No additional production of IL-6 or GM-CSF was observed in infected cultures treated with interferon-gamma (IFN-gamma) despite the ability of IFN-gamma to modestly induce IL-6 in uninfected cultures . Thus, in vitro infection of lung fibroblasts with MP represents a potent stimulus for the production of inflammatory cytokines and, therefore, necessitates rigorous control for these organisms in cell culture studies.(ABSTRACT TRUNCATED AT 250 WORDS)

J Bacteriol, 1993 Apr, 175(8), 2205 - 13
Energy flux and osmoregulation of Saccharomyces cerevisiae grown in chemostats under NaCl stress; Olz R et al.; The energetics and accumulation of solutes in Saccharomyces cerevisiae were investigated for cells grown aerobically in a chemostat under NaCl stress and glucose limitation . Changed energy requirements in relation to external salinity were examined by energy balance determinations performed by substrate and product analyses, with the latter including heat measurements by microcalorimetry . In both 0 and 0.9 M NaCl cultures, the catabolism was entirely respiratory at the lowest dilution rates tested but shifted to a mixed respiratory-fermentative metabolism at higher dilution rates . This shift occurred at a considerably lower dilution rate for salt-grown cells . The intracellular solute concentrations, as calculated on the basis of intracellular soluble space determinations, showed that the internal Na+ concentration increased from about 0.02 molal in basal medium to about 0.18 molal in 0.9 M NaCl medium, while intracellular K+ was maintained around 0.29 molal despite the variation in external salinity . The intracellular glycerol concentration increased from below 0.05 molal at low salinity to about 1.2 molal at 0.9 M NaCl . The concentrations of the internal solutes, however, changed insignificantly with growth rate and energy metabolism . The additional maintenance energy expenditure for growth at 0.9 M NaCl was, depending on the growth rate, 14 to 31% of the total energy requirement for growth at 0 M NaCl . Including the energy conserved in glycerol, the total additional energy demand for growth at 0.9 M NaCl corresponded to 28 to 51% of the energy required for growth at 0 M NaCl.

J Nutr, 1993 Apr, 123(4), 681 - 8
Interaction between methane-producing status and diet on serum acetate concentration in humans; Wolever TM et al.; About half the population excretes methane in the breath . To see if methane producing status influenced serum acetate, we studied six methane producers and six nonproducers on three separate days . For 36 h they ate a polysaccharide-free diet alone, or with 20 g of unabsorbed sugar lactulose, or 20 g of fermentable fiber, guar, in random order . The mean fasting serum acetate concentration on the three test days in producers was higher than in nonproducers, 84 +/- 5 vs . 69 +/- 5 mumol/L (P < 0.05) . Compared to the control diet, both lactulose and guar raised serum acetate concentration significantly in both groups of subjects . However, there was a significant interaction between methane producing status and diet . After lactulose consumption, postprandial serum acetate was similar in both groups of subjects, but guar consumption had a significantly greater effect in producers than nonproducers (98 +/- 8 vs . 73 +/- 5 mumol/L; P < 0.05) . We conclude that methane producing status may influence serum acetate concentrations in humans, depending upon the type of fermentable carbohydrate in the diet.

J Nutr, 1993 Apr, 123(4), 676 - 80
Fate of beta-cyclodextrin in the human intestine; Flourie B et al.; We assessed the fate of beta-cyclodextrin, which is composed of seven alpha(1-->4)-linked glucose units in ring structure, in the human gastrointestinal tract . In four healthy ileostomists, ileal effluent was collected after oral administration of beta-cyclodextrin during fasting (10 g of beta-cyclodextrin) and postprandially (10 g of beta-cyclodextrin three times daily with meals) . In 10 healthy volunteers, the amount of beta-cyclodextrin passing into the colon was determined by means of the breath hydrogen technique using lactulose as a standard, and stools were collected after oral administration of beta-cyclodextrin during fasting (10 g of beta-cyclodextrin) and postprandially (10 g of beta-cyclodextrin three times daily with meals) . In ileostomists, we recovered from the small intestine 91 +/- 5% and 97 +/- 10% (mean +/- SD) of beta-cyclodextrin ingested during fasting and with meals, respectively . In healthy volunteers, H2 excretion in breath after beta-cyclodextrin ingestion was low compared with excretion after lactulose, but only traces of beta-cyclodextrin were recovered in stools . We conclude that beta-cyclodextrin is poorly hydrolyzed in the human small intestine but that it is fermented by the colonic flora with apparent minimal H2 production.

J Dairy Sci, 1993 Apr, 76(4), 1091 - 105
Nonstructural carbohydrate and protein effects on rumen fermentation, nutrient flow, and performance of dairy cows; Aldrich JM et al.; Four multiparous Holstein cows fitted with rumen and duodenal cannulas were used in a 4 x 4 Latin square with 20-d periods . Four diets were formulated for high and low rumen availabilities of nonstructural carbohydrate and protein . Cows were milked and fed three times daily . Milk production averaged 39 kg/d and was unaffected by treatment . Dry matter intake and 4% FCM production were increased by 1 kg/d for cows fed the low rumen-available nonstructural carbohydrate diets . Milk protein percentage was elevated when either the high rumen-available nonstructural carbohydrate or high rumen-available protein diets were fed . Low rumen-available protein diets increased duodenal passage of total essential AA but did not increase passage of Arg, Ile, and Met . Passage of bacterial N was highest (262 g/d) when high rumen-available nonstructural carbohydrate was combined with high rumen-available protein and was lowest when high rumen-available nonstructural carbohydrate was combined with low rumen-available protein (214 g/d) . Diets with low rumen availabilities of protein were not advantageous, possibly because duodenal passage of one or more of the limiting AA was not increased . Passage of bacterial N to the duodenum was highest when rumen availabilities of both nonstructural carbohydrate and protein were high.

J Anim Sci, 1993 Apr, 71(4), 1032 - 40
Effect of nonfiber carbohydrate level and Aspergillus oryzae fermentation extract on intake, digestion, and milk production in lactating dairy cows; Sievert SJ et al.; Eight multiparous, ruminally cannulated Holstein cows averaging 40 d in milk and 575 kg BW at the start of trial were in a replicated 4 x 4 Latin square arrangement (28-d periods) to determine the effects of dietary nonfiber carbohydrate (NFC) level and Aspergillus oryzae fermentation extract (AO) on intake, milk production, and nutrient digestibility . Treatments were 42 or 35% NFC and 0 or 3 g of AO per day arranged as a 2 x 2 factorial . Diets formulated to contain 21% NDF from alfalfa silage (48.4% of ration DM) and 18.5% CP were fed as total mixed rations twice daily . Alteration of dietary NFC level was by partial replacement of shelled corn and soybean meal with wheat middlings and brewers dried grains . Intake of NDF was higher (1.49 vs 1.22% of BW) for 35 than for 42% NFC diets, but DMI was lower (24.1 vs 24.9 kg/d) . Milkfat percentage, ruminal pH, ammonia, acetate (moles/100 moles), and total tract digestibility of fiber were higher for 35% NFC diets; however, ruminal disappearance of DM, CP, and NDF from Dacron bags containing alfalfa hay was not affected (P > .10) by NFC level . Supplementation with AO did not affect (P > .10) DMI, milk yield, or nutrient digestion . Partial replacement of corn with high-fiber byproducts to lower dietary NFC level and correspondingly increase NDF level increased NDF intake but effected only a small change in DMI . Reducing dietary NFC level improved ruminal fermentation and milkfat percentage without significantly affecting milk yield.

Proc Natl Sci Counc Repub China B, 1993 Apr, 17(2), 62 - 9
Recovery and properties of a fructooligosaccharides-producing beta-fructofuranosidase from Aspergillus japonicus CCRC 38011; Su YC et al.; The fungus (Aspergillus japonicus CCRC 38011) was found to be able to produce beta-fructofuranosidase with high transfructosylating activity (Ut), a key enzyme involved in synthesis of fructooligosaccharides from sucrose . The Ut productivities of this microorganism were 191.5 units/ml broth in a 6-L jar-fermentor and 256.1 units/ml broth in a 1000-L pilot-fermentor in a modified medium containing 8% sucrose as a carbon source . Most of the Ut of this microorganism was found to be bound with mycelia . Incubation and sonication treatment extracted this enzyme from mycelia with maximum efficiencies of 66.3% and 44.3%, respectively . On the other hand, homogenization and freeze-thawing treatment had only a small effect on enzyme extraction . The soluble enzyme extracted from mycelia by incubation at pH 5.0 and 40 degrees C for 3 hours could be easily recovered and purified by acetone precipitation . The recovery of Ut from the crude enzyme solution was 99.5% by mixing the solution with an equal volume of acetone at 4 degrees C, followed by centrifugation . The purification factor of acetone precipitation was 15.8 . The optimum pH and temperature of Ut was 5.0 and 65-70 degrees C, respectively . The enzyme was stable at a pH between 4.0 and 5.0 and at a temperature below 60 degrees C.

Curr Opin Biotechnol, 1993 Apr, 4(2), 183 - 7
Biosensors for fermentation control; Pons MN; Over the past year, biosensor development has been an active area of research . The actual application of biosensors in process monitoring and control is limited to a few cases, mainly as a result of difficulties relating to their long-range stability and their sensitivity to interfering compounds . Steam sterilization is no longer a problem though, as the great majority of sensors are part of flow-injection analysis systems.

Appl Microbiol Biotechnol, 1993 Apr, 39(1), 21 - 5
Improvement of performance for cross-flow membrane filtration of pullulan broth; Yamasaki H et al.; To improve the performance of cross-flow membrane filtration of pullulan broth from Aureobasidium pullulans, the effect of the cultivation conditions was examined . In particular, the sucrose concentration in the medium was changed over a wide range . By decreasing the sucrose concentration the distribution of morphology of the microbial cells in the broth changed; the yeast-like form became predominant and, as a result, the specific resistance of the microbial cake was lowered . When the broth was fermented with a sucrose concentration of 2.5% or lower, the filtration characteristics were greatly improved by periodic closure of permeation during cross-flow filtration.

Fiziol Zh Im I M Sechenova, 1993 Apr, 79(4), 61 - 7
{The role of the proteins of the blood plasma in the homeostasis of its amylase and pepsinogen}; Korot'ko GF et al.; Hypervolemia and stimulation of diuresis in dogs was found to decrease the amylolytic activity of the blood plasma and pepsinogen concentration . The number of enzymes bound with blood plasma albumins decreases in hyper-fermentation . The changing connexion of the plasma albumins with the enzymes entails a renal (as well as extrarenal) extraction of the enzymes from the organism and maintenance of their relatively constant concentration and activity in the blood.

J Antibiot (Tokyo), 1993 Apr, 46(4), 545 - 53
Fiscalins: new substance P inhibitors produced by the fungus Neosartorya fischeri . Taxonomy, fermentation, structures, and biological properties; Wong SM et al.; Three new compounds, named fiscalins A, B, and C, were found in culture broth produced by a Neosartorya fischeri . These compounds inhibit the binding of radiolabeled substance P ligand to the human neurokinin (NK-1) receptor, with Ki values of 57, 174, and 68 microM, respectively . Detailed spectroscopic and amino acid analyses led to the elucidation of structures for the three fiscalins . The structures contain an indolyl moiety linked to an athranilic acid derived tricyclic system . The absolute configuration of fiscalin A was determined by X-ray crystallography and chiral amino acid analysis . The presence of fiscalins was detected directly in crude cellular extracts using LC-MS methods.

Int J Syst Bacteriol, 1993 Apr, 43(2), 293 - 6
Proposal of Quinella ovalis gen . nov., sp . nov., based on phylogenetic analysis; Krumholz LR et al.; Quin's oval is a relatively large bacterium often seen in the rumens of sheep fed diets containing some readily fermented carbohydrates . It has not been obtained in axenic cultures, but a number of its features have been determined by various methods, such as studying cell suspensions purified from rumen fluid by differential centrifugation . We obtained similarly purified suspensions from a sheep fed a diet containing a large amount of molasses . Nearly complete 16S rRNA sequence analysis of these cells as well as cells as Selenomonas ruminantium subsp . ruminantium GA192 (ATCC 12561; type strain) and S . ruminantium subsp . lactilytica HD4 (ATCC 27209) was done . These sequences were compared with those of other bacteria . Evolutionary distance estimates indicated that Quin's oval was most closely related to the Selenomonas-Megasphaera-Sporomusa group in the gram-positive phylum but that it belongs in a new genus . We propose the name Quinella ovalis gen . nov., sp . nov., with its description based on previously known features.

FEMS Microbiol Lett, 1993 Mar 15, 108(1), 47 - 52
Arginine utilization by Mycoplasma fermentans is not regulated by glucose metabolism: a 13C-NMR study; Olson LD et al.; 13C-NMR studies on the effect of glucose metabolism on arginine hydrolysis in Mycoplasma fermentans cells have been performed using a continuous perfusion technique . With this procedure we were able to show, in the presence of glucose, the rapid accumulation of lactic acid and, in the presence of arginine, the formation of citrulline that is apparently further metabolized . As the accumulation of lactate and the breakdown of arginine were observed in the simultaneous presence of both substrates, it is suggested that the glucose utilization has little or no effect on the deimination of arginine to citrulline.

Biochem J, 1993 Mar 15, 290 ( Pt 3), 723 - 9
Expression, purification and characterization of B72.3 Fv fragments; King DJ et al.; The Fv fragment of the antibody B72.3 has been produced by expression in both a mammalian and microbial system, namely Chinese hamster ovary (CHO) cells and Escherichia coli . In both cases secretion of the Fv into the culture medium was achieved, with equivalent amounts of Vh and Vl produced . The yield of Fv from CHO cells was 4 mg/l in roller-bottle culture . E . coli proved to be a more productive system with yields of 40 mg/l in shake flasks rising to 450 mg/l in fermentations . B72.3 Fv from both sources was capable of binding to antigen with similar binding ability to the Fab' fragment . A detailed sedimentation analysis, both by velocity and equilibrium techniques, revealed that the two domains of Fv are associated at high concentrations at pH values close to neutral, but dissociate at concentrations lower than approx . 0.5 mg/ml . Individual Vh or Vl polypeptides are not able to bind to the antigen and thus these results suggest that the antigen promotes assembly of Fv at the low concentrations used in the antigen-binding assays . At a pH value of 1.9, Vh and Vl are completely dissociated even at very high concentrations and are apparently unfolded at low solute concentrations . Small-angle X-ray scattering was used to measure a radius of gyration of 1.75 +/- 0.2 nm (17.5 +/- 2 A) for Fv.

FEBS Lett, 1993 Mar 8, 318(3), 345 - 52
Purification and characterization of the trefoil peptide human spasmolytic polypeptide (hSP) produced in yeast; Thim L et al.; Recombinant human spasmolytic polypeptide (r-hSP) has been produced in relatively large amounts in Saccharomyces cerevisiae . The two intronless trefoil domains of the hSP-DNA were cloned separately by PCR from human genomic DNA, and the remaining parts of the gene synthesized . Recombinant plasmids were constructed to encode a fusion protein consisting of a hybrid leader sequence and the hSP sequence . The leader sequence serves to direct the fusion protein into the secretory pathway of the cell and to expose it to the Kex 2 processing enzyme system . The secreted r-hSP was found in a glycosylated and an non-glycosylated form . The two forms of r-hSP were purified from the yeast fermentation broth by a combination of ion-exchange chromatography and preparative HPLC . The overall yield from 8 litres of fermentation broth was 160 mg r-hSP and 219 mg glycosylated r-hSP corresponding to 50% and 34%, respectively . The structure of the r-hSP and the glycosylated r-hSP was determined by amino acid analysis and carbohydrate composition analysis as well as by peptide mapping, amino acid sequencing and mass spectrometric analysis.

FEMS Immunol Med Microbiol, 1993 Mar, 6(2-3), 207 - 12
Porphyromonas-like gram-negative rods in naturally occurring periodontitis in dogs; Karjalainen J et al.; A total of 259 Gram-negative Porphyromonas-like rods isolated from subgingival plaque samples of 16 family-owned dogs with naturally occurring periodontitis were characterized phenotypically by biochemical reactions, metabolic end products and enzymatic activities (API-ZYMTM, RoscoTM) . Four distinct groups were found . Group A isolates (63) were asaccharolytic, lipase negative, trypsin positive and produced phenylacetic acid (PAA) from peptone-yeast extract glucose broth . Unlike P . gingivalis strains they were catalase positive . Group B isolates (42) differed from those of group A by a positive lipase reaction and from those of group D by failing to ferment sugars . Group C isolates (88) were asaccharolytic and did not produce PAA . They were alpha-fucosidase, N-acetyl-beta-glucosaminidase (beta-NAG) and trypsin negative, resembling P . endodontalis, but unlike human isolates, they were catalase positive . Subgroup C.1 isolates (6) differed from those of parent group C by producing minor amounts of PAA, and subgroup C.2 isolates (12) were beta-NAG positive . Group D isolates (46) were weakly fermentative, lipase, catalase and trypsin positive, and produced PAA . They resembled the B (P.) salivosus type strain which, in our hands, fermented weakly glucose, lactose and mannose . Two isolates could not be assigned to any of the previous groups.

Br J Nutr, 1993 Mar, 69(2), 511 - 25
Assessment of fermentation in growing pigs given unmolassed sugar-beet pulp: a stoichiometric approach; Zhu JQ et al.; In four experiments growing pigs were given a cereal-based diet alone or supplemented with unmolassed sugar-beet pulp (SBP), used as a model substrate for fermentation . The rates of production of methane and gaseous hydrogen were measured and, together with the molar proportions of volatile fatty acids (VFA) in the digesta, used in stoichiometric calculations of fermentation . The resulting estimates were only one-sixth of the observed extent of digestion of SBP . Bacteriostatic levels of antibiotics reduced fermentation by more than half, as judged from the digestion of non-starch polysaccharides: allowing for the incomplete suppression of fermentation it was estimated that the production of methane and VFA could account completely for the digested SBP . The potential contribution of various routes of hydrogen disposal to the error of the stoichiometric calculations is discussed.

Br J Nutr, 1993 Mar, 69(2), 497 - 509
Complex carbohydrate digestion and large bowel fermentation in rats given wholemeal bread and cooked haricot beans (Phaseolus vulgaris) fed in mixed diets; Key FB et al.; The digestion of non-starch polysaccharides (NSP) and of resistant starch (RS) by rats fed on wholemeal-bread-based diets containing 0-450 g cooked, freeze-dried haricot beans (Phaseolus vulgaris)/kg diet was measured over the final 14 d of a 21 d feeding experiment . The bread and beans provided all the dietary polysaccharide . RS could not be detected consistently in faeces and it was assumed that this fraction was entirely fermented in the large bowel (LB) . NSP digestibilities were 0.56 and 0.86 for wholemeal bread and beans respectively with no evidence that the dietary presence of beans affected digestibility of bread NSP . Bean non-cellulosic polysaccharides were highly digestible with values of 0.98, 0.88 and 0.99 for arabinose, xylose and uronic acids components respectively . There were large increases in organic matter flow to the LB when beans were fed which was associated with marked caecal hypertrophy and alterations in caecal volatile fatty acids (VFA) pattern . Calculated VFA absorption from the LB was 5-fold higher with the highest level of beans and this was reflected in higher concentrations of VFA in portal and heart blood.

Br J Nutr, 1993 Mar, 69(2), 481 - 95
Gastrointestinal responses of rats fed on white and wholemeal breads: complex carbohydrate digestibility and the influence of dietary fat content; Key FB et al.; To obtain quantitative information on the digestibility of the non-starch polysaccharides (NSP) fraction of white and wholemeal breads, rats were fed on diets in which freeze-dried bread (white, wholemeal or mixtures of the two) provided all the complex carbohydrates . In a second experiment the possibility that dietary fat concentration might influence NSP digestibility was tested by feeding diets containing 30 or 170 g maize oil/kg and either white or wholemeal bread . Multiple linear regression analysis provided little evidence of associative effects of dietary components on NSP digestibility and in the two experiments digestibilities of NSP for white and wholemeal breads were 0.77-0.82 and 0.47-0.52 respectively . Xylose- and arabinose-containing polymers were better digested than was cellulose for both breads . Replacing white by wholemeal bread markedly increased the molar proportion of butyrate in caecal volatile fatty acids at the expense of acetate . This was associated with greater flows of organic matter to the large bowel (LB) and a reduction in caecal transit time (Expt 2) . There was little detectable effect of dietary maize oil concentration on NSP digestibility or on LB fermentation . All breads contained some starch resistant to pancreatic alpha-amylase (EC 3.2.1.1) without previous treatment with dimethyl sulphoxide . The digestibility of this starch fraction was not significantly different from 1.0 for all diets except that containing wholemeal bread and the higher maize oil concentration where the apparent digestibility was 0.89.

Metabolism, 1993 Mar, 42(3), 347 - 52
Effects of colonic fermentation on respiratory gas exchanges following a glucose load in man; Ritz P et al.; Colonic fermentation produces short-chain fatty acids (SCFA) . In humans, the amount of energy produced from the oxidation of these compounds is unknown and could modify the metabolic utilization of energetic fuels (eg, carbohydrates and lipids) . If it were so, the equations used to evaluate the oxidation of nutrients from indirect calorimetry data should include the contribution of SCFA, which is not usually the case . Indeed, this fermentation process is usually considered as a minor and neglected energetic pathway . In this study, we have addressed the reliability of this assumption . Six normal subjects received orally either 50 g glucose or 50 g glucose plus 20 g lactulose . Their respiratory gas exchanges, breath hydrogen, methane, and 13CO2 concentrations, and plasma glucose, insulin, and free fatty acid (FFA) concentrations were monitored for 8 hours . CO2 production and breath hydrogen concentration were significantly greater with lactulose . No differences in oxygen consumption, breath 13CO2 production, or plasma concentrations of blood glucose, FFA, and insulin could be found between the two experiments . This suggests that the fermentation process induced by lactulose generates extra fuels going through an oxidation pathway . Therefore, the classic equations used to calculate carbohydrate and lipid oxidation and energy expenditure (EE) from indirect calorimetry data are probably not valid when fermentation is taking place . Indeed, in this experiment we could have overestimated glucose oxidation (12.5%) if the fermentation process were not considered . In conclusion, colonic fermentation in humans of nondigestible carbohydrates produces energetic substrates that could be used and oxidized as energetic fuels.(ABSTRACT TRUNCATED AT 250 WORDS)

Appl Environ Microbiol, 1993 Mar, 59(3), 786 - 90
Evaluation of colilert-marine water for detection of total coliforms and Escherichia coli in the marine environment; Palmer CJ et al.; A test that allows for early detection of fecally contaminated coastal water would enhance public health protection . Colilert-Marine Water (Colilert-MW; Environetics, Branford, Conn.) is a rapid 24-h test that has recently been developed to detect total coliforms and Escherichia coli in coastal water . We performed a premarketing evaluation of the Colilert-MW product, testing it in parallel with the multiple tube fermentation (MTF) method for 86 coastal water samples in southern California . Statistical analysis was performed by using paired t tests and linear regression . Bacterial isolates were evaluated by biochemical and genetic analysis . The results of this study showed a strong correlation between the traditional MTF and the Colilert-MW method for detection of total coliforms (r = 0.95) and E . coli (r = 0.89) in ocean water samples . Paired t-test results indicated that the Colilert-MW and MTF were equivalent in detecting E . coli and that the Colilert-MW may be more sensitive in the detection of total coliforms . We conclude that Colilert-MW would be a useful tool with which to monitor coastal beach water.

Appl Environ Microbiol, 1993 Mar, 59(3), 748 - 55
Glucose and carbon dioxide metabolism by Succinivibrio dextrinosolvens; O'Herrin SM et al.; Growth rates and culture conditions affect the molar yields of catabolic end products and cells of Succinivibrio dextrinosolvens growing on glucose . When growth in chemostats occurred, a trend toward decreased succinate and acetate formation, increased lactate formation, and a higher yield of cells correlated with an increase in the growth rate . End product and cellular yields on defined medium indicate a high maintenance requirement for S . dextrinosolvens and are consistent with energy conservation steps during the formation of acetate and succinate . Simultaneous carbon dioxide consumption and production were determined from batch studies with NaH14CO3, and the amounts were used to calculate a fermentation balance . These data also indicated that CO2 consumption lags behind CO2 production early in the growth phase, becoming equivalent to it toward stationary phase . Significantly more CO2 was fixed by S . dextrinosolvens when the organism was cultured in chemostats sparged with CO2 . Formate is in part derived from free CO2 in the medium, as shown by 13C nuclear magnetic resonance studies, and may be sensitive to CO2 availability . Nuclear magnetic resonance data are consistent with the carboxylation of a C3 intermediate of the Embden-Meyerhof-Parnas pathway of glycolysis to a C4 compound to eventually form succinate.

Appl Environ Microbiol, 1993 Mar, 59(3), 729 - 33
Production of high concentrations of ethanol from inulin by simultaneous saccharification and fermentation using Aspergillus niger and Saccharomyces cerevisiae; Ohta K et al.; Pure nonhydrolyzed inulin was directly converted to ethanol in a simultaneous saccharification and fermentation process . An inulinase-hyperproducing mutant, Aspergillus niger 817, was grown in a submerged culture at 30 degrees C for 5 days . The inulin-digestive liquid culture (150 ml) was supplemented with 45 g of inulin, 0.45 g of (NH4)2SO4, and 0.15 g of KH2PO4 . The medium (pH 5.0) was inoculated with an ethanol-tolerant strain, Saccharomyces cerevisiae 1200, and fermentation was conducted at 30 degrees C . An additional 20 g of inulin was added to the culture after 15 h of fermentation . S . cerevisiae 1200 utilized 99% of the 65 g of inulin during the fermentation, and produced 20.4 and 21.0% (vol/vol) ethanol from chicory and dahlia inulins, respectively, within 3 days of fermentation . The maximum volumetric productivities of ethanol were 6.2 and 6.0 g/liter/h for chicory and dahlia inulins, respectively . The conversion efficiency of inulin to ethanol was 83 to 84% of the theoretical ethanol yield.

J Antibiot (Tokyo), 1993 Mar, 46(3), 420 - 9
Biosynthesis of the pradimicin family of antibiotics . II . Fermentation, isolation and structure determination of metabolites associated with the pradimicins biosynthesis; Tsuno T et al.; Ten metabolites produced by 4 mutants derived from Actinomadura verrucosospora subsp . neohibisca E-40, a high pradimicins producer, were isolated and their structures were determined . Strain JN-219 produced 3 novel analogs of the pradimicin A aglycone, i.e . 11-O-demethyl-7-methoxypradinone II and 11-O-demethylpradinones I and II together with a known aglycone analog, pradinone I, while the metabolites from strain JN-47 were determined to be 2 new aglycone analogs, 11-O-demethylpradimicinone I and 11-O-demethyl-7-methoxypradimicinone II and a known aglycone analog, 11-O-demethylpradimicinone II (11dM-PMN II) . Products of strain JN-207 were identified as 11-O-demethyl-6-deoxypradinone I and 11dM-PMN II . Interestingly, a new pradimicin analog, 7-hydroxypradimicin A was isolated from strain JN-58 together with a new aglycone analog, pradimicinone II and 11dM-PMN II . None of these metabolites showed antifungal activity.

J Antibiot (Tokyo), 1993 Mar, 46(3), 412 - 9
Biosynthesis of the pradimicin family of antibiotics . I . Generation and selection of pradimicin-nonproducing mutants; Furumai T et al.; Germinated spores of Actinomadura verrucosospora subsp . neohibisca E-40, a high pradimicins producer, were mutagenized by N-methyl-N'-nitro-N-nitrosoguanidine and/or UV treatment . Thirty-seven mutants which did not produce pradimicin were selected to test for cosynthesis ability, and classified into nine classes . On the basis of their cosynthesis ability and bioconversion results, we concluded that strain JN-213 (class III) was a true converter and that strains JN-219 (class IV), JN-47 (class V) and JNU-46 (class VI) were secretors accumulating biosynthetic intermediates of pradimicin, and that strains JN-59 (class VII), JN-58 (class VIII) and JN-207 (class IX) were producers of shunt metabolites of pradimicin biosynthesis . TLC and HPLC analyses of the fermentation broths of individual strains showed that 8 new compounds were produced along with pradinone I, pradimicinone I, 11-O-demethylpradimicinone II and 7-O-methylpradimicinone II.

J Antibiot (Tokyo), 1993 Mar, 46(3), 380 - 6
5-N-acetylardeemin, a novel heterocyclic compound which reverses multiple drug resistance in tumor cells . II . Isolation and elucidation of the structure of 5-N-acetylardeemin and two congeners; Hochlowski JE et al.; A family of novel compounds has been detected and isolated following an assay for the attenuation of multiple drug resistance in tumor cells from the fermentation broth and mycelia of a strain of Aspergillus fischeri which we have designated var . brasiliensis . The structures of three components were determined employing 1-D and 2-D homonuclear and heteronuclear NMR spectroscopy and mass spectrometry . The structure of 5-N-acetylardeemin was confirmed by single crystal X-ray diffraction . These compounds are most closely structurally related to asperlicin E1).

J Antibiot (Tokyo), 1993 Mar, 46(3), 374 - 9
5-N-acetylardeemin, a novel heterocyclic compound which reverses multiple drug resistance in tumor cells . I . Taxonomy and fermentation of the producing organism and biological activity; Karwowski JP et al.; The ardeemins are a new family of secondary metabolites produced by submerged fermentation of a fungus which was isolated from a soil sample collected in Brazil . Based on taxonomic studies, the producing culture was identified as Aspergillus fischeri var . brasiliensis strain AB 1826M-35 . 5-N-Acetylardeemin potentiated the cytotoxicity of the anticancer agent vinblastine in multidrug resistant human tumor cells.

Chem Pharm Bull (Tokyo), 1993 Mar, 41(3), 557 - 60
Two new steroidal saponins from dried fermented residues of leaf-juices of Agave sisalana forma Dong No . 1; Ding Y et al.; In a previous paper, we reported the isolation and structure determination of three new steroidal saponins, dongnosides C (3), D (2) and E (1) from the dried fermented residues of leaf-juices of Agave sisalana forma Dong No . 1 . In a continuing study on this plant, two additional new major steroidal saponins, named dongnosides B (4) and A (5), were obtained . Their structures were characterized respectively as tigogenin 3-O-alpha-L-rhamonpyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->2)- {beta-D- glucopyranosyl-(1-->3)}-beta-D-glucopyranosyl-(1-->4)-beta-D-galactop yranoside and 3-O-alpha-L-rhamnopyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->2)-{beta- D- xylopyranosyl-(1-->3)-beta-D-glucopyranosyl-(1-->3)}-beta-D- glucopyranosyl-(1-->4)-beta-D-galactopyranoside on the basis of chemical and physicochemical evidence.

J Dairy Sci, 1993 Mar, 76(3), 826 - 30
Another theory for the action of ruminal buffer salts: decreased starch fermentation and propionate production; Russell JB et al.; Sodium carbonates have been fed to ruminants for more than 20 yr and, in many cases, have alleviated milk fat depression . These effects usually have been ascribed to increased ruminal buffering capacity, but this mode of action has several problems . For the buffering capacity to increase, the concentrations of ruminal bicarbonate, dissolved CO2, and Na have to increase . Ruminal fluid already is saturated with CO2, and the cation concentration of ruminal fluid is regulated closely to prevent hemoconcentration or hemodilution . Based on these latter observations, a significant increase in ruminal buffering capacity is unlikely . The action of bicarbonates is explained more easily by increased water intake, increased ruminal fluid dilution rate, increased flow of undegraded starch from the rumen, and decreased ruminal propionate production.

J Dairy Sci, 1993 Mar, 76(3), 775 - 89
Diets containing high oil corn and tallow for dairy cows during early lactation; Elliott JP et al.; Four multiparous Holstein cows averaging 49 DIM and fitted with ruminal cannulas were utilized in a 4 x 4 Latin square design with 21-d periods to determine the effects of diets containing high oil corn grain and tallow . Cows were fed diets of alfalfa haylage and concentrate (37:63, DM basis) for ad libitum intake . Treatments were 1) control, no added fat; 2) high oil corn grain replacing regular corn grain; 3) high oil corn grain and 2.5% tallow; and 4) high oil corn grain and 5% tallow . Intake of DM, milk production, and yields of milk fat, milk protein, milk SNF, and 4% FCM were not affected by dietary fat, although DMI tended to be lower when cows were fed 5% tallow . Percentages of protein and SNF in milk were lower when cows were fed diets containing fat . Percentage of milk fat was lower when cows were fed diets containing tallow . Supplemental fat decreased total VFA concentrations in ruminal fluid . Cows fed high oil corn had a greater molar proportion of acetate and a larger acetate to propionate ratio in ruminal fluid than cows fed high oil corn and tallow . Digestibility of total fatty acids decreased when tallow was added to diets containing high oil corn . No differences were observed among treatments for total tract apparent digestibilities of DM and fiber or utilization of energy and N . Dietary high oil corn and 5% tallow tended to decrease DMI and to alter ruminal fermentation characteristics.

Clin Exp Metastasis, 1993 Mar, 11(2), 201 - 12
U-77,863: a novel cinnanamide isolated from Streptomyces griseoluteus that inhibits cancer invasion and metastasis; Welch DR et al.; Several cinnamoyl compounds have been shown to have antitumor activities, but not specifically anti-invasive or antimetastatic effects . U-77,863 (o-methyl cinnanamide) was originally isolated from a fermentation beer of Streptomyces griseoluteus and recently synthesized (Harper, DE and Welch DR . Journal of Antibiotics, in press) . Based upon some differential activities of cinnanamides, in general, and U-77,863, specifically, we tested the hypothesis that U-77,863 could inhibit invasion and metastasis of human malignant melanoma cell lines C8161 and A375M . Pretreatment of melanoma cells in vitro with nontoxic doses of U-77,863 caused a dose-, and time-dependent, reversible reduction (IC50 = 12.5 micrograms/ml) of invasion through Matrigel-coated polycarbonate filters in the Membrane Invasion Culture System (MICS) . Likewise, lung colonization was significantly (P < 0.05) inhibited when tumor cells were pretreated in vitro with U-77,863 prior to intravenous injection . Structure-activity analysis revealed that the acrylamide side-chain alone and cinnanamide were only slightly less potent than U-77,863, whereas cinnamic acid analogs did not inhibit tumor cell invasion at doses < or = 100 micrograms/ml . U-77,863 inhibits invasion and metastasis without decreasing growth rates or clonogenic potential . Adhesion to endothelial monolayers or extracellular matrices (Matrigel) is not affected by exposure to U-77,863 . U-77,863 presumably inhibits metastasis by inhibiting tumor cell extravasation (invasion) . U-77,863 is a lead compound for developing a novel class of anti-invasive/anti-metastatic drugs.

Z Gastroenterol, 1993 Mar, 31(3), 179 - 82
The application of 13C-labelled short chain fatty acids to measure acetate and propionate production rates in the large intestines . Studies in a pig model; Breves G et al.; The production rates of acetate and propionate were measured in the large intestine of pigs by applying the single injection technique of (1-13C)acetate and (1-13C)propionate . Both acids were injected individually through the caecal cannula and for both acids the experiments were performed during two diets with different crude fibre contents . For acetate the increase of dietary crude fibre from 5.1 to 18.3% of dry matter resulted in an increase of mean production rate from 27.4 to 56.2 mmol/h . The mean propionate production rate was raised from 3.6 to 7.0 mmol/h when the dietary crude fibre was increased from 4.4 to 24.3% . From both experimental series the contribution of hindgut fermentation to energy maintenance requirement were estimated to be in a range between 7 and 40% depending on the body weight of the animals and the percentage of dietary crude fibre.

Gut, 1993 Mar, 34(3), 386 - 91
Butyrate production from dietary fibre and protection against large bowel cancer in a rat model; McIntyre A et al.; Butyrate slows the growth of cancer cells cultured in vitro . To determine the relevance of the fermentative production of butyrate in vivo, colonic butyrate concentrations were manipulated by feeding different dietary fibres and were related to tumour development in the rat dimethylhydrazine model of large bowel cancer . It has previously been shown that guar gum and oat bran, while highly fermentable, are associated with low butyrate levels in the distal colon, while wheat bran causes significantly higher concentrations . Diets containing these fibres (nominally 10% w:w) were administered for 3 weeks before, for 10 weeks during, and for 20 weeks after dimethylhydrazine administration, after which animals were killed and examined for tumours . Significantly fewer tumours were seen in the rats fed wheat bran compared with those fed guar or oat bran, and the total tumour mass was lowest in rats fed wheat bran . Rats on a 'no added fibre diet' had an intermediate tumour mass . Regression analysis, performed regardless of dietary group, showed that the concentration in stools of butyrate but not of acetate or stool volume, correlated significantly (and negatively) with tumour mass . These findings indicate that fibre which is associated with high butyrate concentrations in the distal large bowel is protective against large bowel cancer, while soluble fibres that do not raise distal butyrate concentrations, are not protective . Thus, butyrate production in vivo does bear a significant relationship to suppression of tumour formation.

J Anim Sci, 1993 Mar, 71(3), 788 - 95
Periparturient changes in intake, ruminal capacity, and digestive characteristics in beef cows consuming alfalfa hay; Stanley TA et al.; Four multiparous, ruminally fistulated Angus x Hereford cows (average BW = 568 kg) were bred to the same bull and used to monitor periparturient changes in DMI, ruminal capacity, and digestion and fermentation characteristics . Cows were individually fed alfalfa hay (16.0% CP, 51.3% NDF) at 130% of the average DMI of the previous 5-d period . Ruminal capacity and DM fill were measured once every 2 wk by removing the ruminal contents from each cow and filling the empty rumen with water . Dry matter intake was measured daily . Ruminal VFA, pH, NH3, and total tract DM digestibility (DMD) were measured during three 7-d periods (average of 58 d before calving, 16 d before calving, and 25 d after calving) . Ruminal capacity and DM fill varied in a quadratic manner (P < .01); both were least 6 d before calving . Forage DMI (quadratic effect; P = .02) increased moderately during the prepartum period but increased dramatically after parturition . Although postpartum (d 22) ruminal capacity was only 5% greater than at 61 d before calving, postpartum DMI was 69% greater than DMI measured 61 d before calving . Indigestible ADF (IADF) passage rate changed quadratically with period (P = .01); the greatest IADF passage rate was observed 6 d before calving . Ruminal VFA (mM) also tended to change quadratically (P = .08); the highest concentrations occurred 25 d after calving . The acetate:propionate ratio declined linearly with period (P = .01) . Ruminal fluid dilution rate, pH, NH3, and DMD did not change significantly over time.(ABSTRACT TRUNCATED AT 250 WORDS)

J Anim Sci, 1993 Mar, 71(3), 779 - 87
Influence of Aspergillus oryzae fermentation extract on forage intake, site of digestion, in situ degradability, and duodenal amino acid flow in steers grazing cool-season pasture; Caton JS et al.; Ten ruminally and duodenally cannulated (326 +/- 28 kg) and four esophageally fistulated (394 +/- 23 kg) steers grazing cool-season pasture throughout the growing season were used to evaluate the influence of Aspergillus oryzae fermentation extract (AO) supplementation on intake, forage nutrient utilization, and duodenal amino acid flow . Steers grazed a predominantly smooth brome (Bromus inermis L.) pasture, and measurements were taken in three periods (June, July, and August) . Steers were dosed daily at 0700 via the ruminal cannula with AO (2 g of AO per steer daily; DM basis) or not supplemented with AO . Each period consisted of 18 d for adaption to AO and 7 d for collection . Forage N was greater, and ADF was lower (P < .10), in June than in July and August . Ruminal pH, ammonia, total VFA concentration, and VFA proportions were not affected (P > .10) by AO supplementation . In vitro DM digestibility (percentage) and forage OM intake (grams/kilogram of BW) were greater (P < .10) for steers supplemented with AO . Ruminal and total tract NDF and ADF digestibilities were lower in June and greater during July (P < .10) in steers supplemented with AO . Total tract percentage of N disappearance was lesser during June and greater (P < .10) during July for steers receiving AO . Total, essential, and nonessential amino acid flows were increased (P < .10) by both AO supplementation and advancing season . In situ rate of ruminal CP degradation was not affected (P < .10) by treatment during any period.(ABSTRACT TRUNCATED AT 250 WORDS)

Am J Gastroenterol, 1993 Mar, 88(3), 420 - 3
Fermentation of the carbohydrate of banana (Paradisiaca sapientum) in the human large intestine; Segal I et al.; Fermentation of dietary fiber and resistant starch is one of the major physiological functions of the human large intestine . The major substrate for fermentation is probably starch . This study assessed the effect of bananas--a carbohydrate with a highly resistant starch content--on breath hydrogen and methane production in methane and nonmethane-producing subjects . The results showed that both groups produced significant quantities of hydrogen after a banana meal, compared with a sucrose control test meal, measured as area under the curve (28 +/- 5.6 vs . 8.1 +/- 1.4 10(3) pm/min, p = 0.008 in methane producers and 39 +/- 15.2 vs . 10.5 +/- 4.1 10(3) ppm/min, p = 0.01 in methane nonproducers) . The rise in breath hydrogen started a half hour after the banana meal and peaked at 3 1/2 h in methane nonproducers, whereas in methane producers, the rise began after 2 h and peaked at 5 h . Methane production was not significantly stimulated by the test meals . This study shows that bananas stimulate fermentation mainly through the production of hydrogen, with minimal effect on methane production . The possible mechanisms for this process are discussed.

Fetal Diagn Ther, 1993 Mar-Apr, 8(2), 74 - 8
Bacterial and fungal contamination of human fetal liver collected transvaginally for hematopoietic stem cell transplantation; Rice HE et al.; Transplantation of fetal hematopoietic stem cells is a new therapy for fetuses diagnosed in utero with inherited disorders . However, prior to transplantation of fetal stem cells, the cells must be free of microbial contamination . In order to investigate the contamination of human fetal liver tissue, we determined the rate and types of bacterial and fungal contamination of human fetal liver tissue collected transvaginally for use in stem cell transplantation by using the US Pharmacopoiea Assay . We found a high rate of contamination with bacteria or fungi (12 of the 14 fetal livers, or 85%) . Non-fermenting gram-negative rods were the predominant contaminants . The high rate of microbial contamination of fetal tissue suggests that techniques for tissue collection need to be improved before fetal stem cells are used for clinical transplantation.

Appl Microbiol Biotechnol, 1993 Mar, 38(6), 770 - 5
High-level production and secretion of a mouse-human chimeric Fab fragment with specificity to human carcino embryonic antigen in Escherichia coli; Shibui T et al.; A high-level secretion system for the production of mouse-human chimeric antibody 21B2 (MHC 21B2) Fab fragment specific for human carcino embryonic antigen (hCEA) in Escherichia coli has been constructed . The genes encoding a light chain and an Fd fragment (a variable region and the CH1 domain of a heavy chain) of a mouse-human chimeric antibody were directly fused to the signal peptide of the E . coli ompF gene sequence . E . coli cells containing expression vectors in which each of the two genes are located downstream of a separate tac promoter were able to secrete the light chain and Fd fragment as two of their major cellular proteins . The signal peptides were efficiently removed from the primary products by post-translational processing, although they formed insoluble aggregates, possibly in the periplasm . In high-cell-density culture experiments using a jar fermentor, the amount of light chain and Fd fragment produced was at levels of up to 2.88 g/l and 1.28 g/l culture, respectively . By optimizing the conditions that encourage correct folding, formation of disulphide bonds, and association of the light chain with the Fd fragment, we have established a procedure that can purify, re-fold, and combine aggregated products to electrophoretically homogeneous Fab fragment with a yield of approximately 47% . Fab fragment produced in this manner shows essentially the same antigen-binding activity and specificity to hCEA as the parental mouse antibody 21B2 (MoAb 21B2).

Appl Microbiol Biotechnol, 1993 Mar, 38(6), 719 - 27
High yield fermentation and purification of Tendamistat disulphide analogues secreted by Streptomyces lividans; Haas-Lauterbach S et al.; In our studies of structure-function correlation of polypeptides we used Tendamistat (TM), an alpha-amylase-inhibitor of Streptomyces tendae, as a model to investigate the influence of different mutants on the expression and secretion of the protein . In addition, we examined the influence of replacing the two disulphide-bridges that stabilize the two-loop structure of the whole protein . The single mutants C27S, C27T, C45A, the double mutants C11A/C27A, C11A/C27S, C11A/C27T, C11A/C27L, C45/C73A and the fourfold mutant C11A/C27A/C45A/C73A were prepared . The mutated TM gene was expressed in S . lividans TK 24, which secretes the active form of the inhibitor into the culture medium . Compared with the wild-type, the double-mutated TM derivatives show an increase in secreted protein by a factor of two to ten . In contrast, the single-mutated inhibitor analogues show the reverse effect . In order to examine the influence of temperature and culture media on the production of protein derivative we used the most unstable C11A analogue . Our expression studies at 10, 19, 28 and 37 degrees C established 19 degrees C as the optimal temperature for production of the protein derivatives . The correlation between the stability and secretion of TM is discussed in the context of our knowledge of protein translocation in bacteria . Based on these experiments we optimized the fermentation parameters, isolated TM analogous on a large scale, and verified them.

Biotechnology (N Y), 1993 Mar, 11(3), 381 - 6
Construction of metabolic operons catalyzing the de novo biosynthesis of indigo in Escherichia coli; Murdock D et al.; The efficient production of the textile dye indigo by fermentation has been a goal since the early 1980's when the first bacterial strains capable of this synthesis were constructed . We report here the development of a recombinant microorganism that directly synthesizes indigo from glucose . This construction involved the cloning and genetic manipulation of at least 9 genes and modifications of the fermentation medium to help stabilize the biosynthetic activity . Directed genetic changes in two operons caused significant increases in reaction rates and in the stability of the catalytic enzymes . This example of whole cell catalysis by a recombinant Escherichia coli represents a novel and environmentally sound approach to the synthesis of a high value specialty chemical.

Biotechnology (N Y), 1993 Mar, 11(3), 349 - 57
Process economics of animal cell and bacterial fermentations: a case study analysis of tissue plasminogen activator; Datar RV et al.; One link in the complex chain of medical economics is the cost of bringing new drugs and biologicals to the market . Advances in recombinant-DNA technology permit production of therapeutically active proteins in effectively unlimited quantities . Nevertheless, each expression system has a characteristic influence on the nature of the product produced and the process required to obtain it . In this case study we compare experiences with recombinant-tissue plasminogen activator (rtPA) produced in Chinese hamster ovary (CHO) cells and in Escherichia coli, with the aim of understanding the roles of some of the parameters that affect process economics . tPA belongs to the group of highly specific serine proteases that convert plasminogen to plasmin, which in turn degrades several protein substrates including fibrin, thus making it an effective thrombolytic agent . The treatment of acute myocardial infarction with such thrombolytic agents can result in early discharge of patients and decreased medical costs . However, there are major differences in the prices of the various available agents . The price of the FDA-licensed tPA product is $2,200 per dose or $22,000 per gram . It is believed that a significant portion of this price relates to manufacturing costs . We examine by way of case study illustration the cost breakdown for the two processes, and highlight important process, design and economic considerations that ultimately define a particular protein product.

Mikrobiol Zh, 1993 Mar-Apr, 55(2), 99 - 104
{The inhibitory action of 6-azacytidine on Mollicutes and its proposed mechanism}; Skripal' IG et al.; 6-Azacytidine (6-AC) is shown to have an inhibitory effect on the Mollicutes of the different systematic position . The growth of type strains of Mollicutes (Acholeplasma laidlawii PG-8, Mycoplasma pneumoniae FH and M . fermentans PG-18) completely ceased in the nutrient medium at concentration of the above substance in it within the range of 125-250 micrograms/ml . 50% inhibiting concentration of 6-AC equaled: for M . fermentans PG-8: 23.43 micrograms/ml; M . pneumoniae FN: 46.8 micrograms/ml; Acholeplasma laidlawii PG-8: 62.5 micrograms/ml . 6-AC concentration 5 micrograms/ml decreased the process of DNA-dependent DNA synthesis in the in vitro system more than by 60% . 6-AC exerted less effect on the DNA-dependent RNA synthesis in the in vitro system: at different concentrations of 6-AC (up to 400 micrograms/ml) RNA synthesis decreased only by 20% . Translation on ribosomes of Mollicutes in the in vitro system completely ceased at 6-AC concentration 100 micrograms/ml . The results obtained indicate that for 6-AC in cells of Mollicutes and, possibly, for other microorganisms there are two targets: ribosomes and DNA-dependent DNA-polymerase . Total effect of blocking of the translation and replication processes by 6-azacytidine causes death of Mollicutes . Since 6-AC has no harmful effect on the human cells, it can be used as an efficient method for treatment of respiratory and urogenital diseases induced by Mollicutes.

J Immunol Methods, 1993 Feb 26, 159(1-2), 229 - 34
Nanogram quantitation of secreted protein in a recombinant yeast fermentation using an immuno-ligand assay; Robinett RS et al.; A liquid-phase immuno-ligand assay has been developed for quantitative determination of recombinant tick anticoagulant protein (rTAP) secreted in yeast fermentations . A polyclonal anti-TAP antibody was labeled with biotin or fluorescein . Labelled antibodies were used in a non-competitive sandwich format to capture rTAP from solution, then reacted with urease-conjugated anti-fluorescein antibody . Detection of the immune complex was by a commercially available silicon-based potentiometric sensor which measures urease activity . Sample throughput was 90 samples per 7 h with a 2 h incubation time . The range of the standard curve was 0.1-10 ng/ml with an assay sensitivity of 0.025 ng/ml . For a mid-range concentration of 1 ng/ml, intraday and interday method precision was determined to be 1.031 +/- 0.061 and 1.077 +/- 0.026 ng/ml, respectively . Typically, spiked samples of 1 microgram rTAP/ml fermentation medium required dilutions of 1/1000 to generate a response in the mid-range of the standard curve . This assay provides a convenient method to quantitate product expression in multiple fermentation samples within 3 h after sampling . In addition, a modified version of the assay was developed which provided accurate results within 1 h of sample acquisition.

Int J Exp Pathol, 1993 Feb, 74(1), 97 - 101
Factors influencing the ability of different mycoplasmas to colonize the genital tract of hormone-treated female mice; Furr PM et al.; Colonization of the genital tract of female mice, mainly BALB/c, by Mycoplasma genitalium, M . pneumoniae and M . pulmonis was enhanced by pretreatment of the mice with progesterone . M . fermentans, M . hominis and M . salivarium, and three serotypes and two untyped strains of Ureaplasma urealyticum colonized under the influence of oestradiol but not progesterone . Mycoplasmas dependent on progesterone were glucose-metabolizing, with strong haemadsorptive and other attachment properties, and possessed a terminal structure . Mycoplasmas dependent on oestradiol were arginine or arginine/glucose metabolizing . Ureaplasmas also required oestradiol . The oestradiol-requiring group appeared to be less cytadsorptive and devoid of a morphological terminal structure . Mycoplasmas that had had multiple passes in media were less able to colonize . This may be one, but not the only, reason for the failure of seven mycoplasmas to colonize under the influence of either hormone . The observations suggest the existence of a receptor mechanism for colonization, progesterone-requiring mycoplasmas being exposed to, and needing, genital tract cells different from those exposed to oestradiol-requiring mycoplasmas.

J Antibiot (Tokyo), 1993 Feb, 46(2), 275 - 9
Three novel polyether antibiotics X-14889A, C, and D from a streptomycete . Taxonomy of the producing organism, fermentation production and biological properties of the antibiotics; Liu CM et al.; Antibiotic X-14889A, C, and D are novel polyether antibiotics related to lysocellin and antibiotic X-14873A . They are produced by a streptomycete isolated from a soil of Wisconsin . The antibiotic X-14889C is active against Gram-positive bacteria and exhibits ionophore property.

J Antibiot (Tokyo), 1993 Feb, 46(2), 265 - 74
BMS-181184, a new pradimicin derivative . Screening, taxonomy, directed biosynthesis, isolation and characterization; Furumai T et al.; BMS-181184 is a new semisynthetic pradimicin derivative with a broad-spectrum antifungal activity . In a search for actinomycetes producing BMS-181184, 4 strains of Actinomadura sp . isolated from soil samples were found to produce the antibiotic under conditions of directed biosynthesis . Among them, Actinomadura sp . AB1236 proved most useful in the production of BMS-181184 when fermented in a medium containing D-serine and D-cycloserine . A minor product isolated from the broth of strain AB1236 was identified as the dexylosyl analog of BMS-181184, which was also obtained by acid hydrolysis of BMS-181184.

J Antibiot (Tokyo), 1993 Feb, 46(2), 251 - 4
AB023, novel polyene antibiotics . I . Taxonomy of the producing organism, fermentation and antifungal activity; Cidaria D et al.; AB023 is a complex of polyene antibiotics produced by an actinomycete, SD581, which was isolated from a Kenyan soil sample . The two main components, pentaene antibiotics AB023a and AB023b, have antifungal activity against some phytopathogenic fungi, particularly against Botrytis cinerea (MIC of 5 micrograms/ml).

J Antibiot (Tokyo), 1993 Feb, 46(2), 247 - 50
Mer-WF3010, a new member of the papulacandin family . I . Fermentation, isolation and characterization; Kaneto R et al.; Mer-WF3010, a new member of the papulacandin family, was isolated from the mycelia of Phialophora cyclaminis Mer-WF3010 (FERM P-11475) . The molecular formula of Mer-WF3010 was determined as C45H60O16.

J Antibiot (Tokyo), 1993 Feb, 46(2), 222 - 8
Pepticinnamins, new farnesyl-protein transferase inhibitors produced by an actinomycete . I . Producing strain, fermentation, isolation and biological activity; Omura S et al.; Pepticinnamins A, B, C, D, E and F, a family of farnesyl-protein transferase (FPT) inhibitors were isolated from the fermentation broth of Streptomyces sp . OH-4652 . These inhibitors were purified from whole broth by extraction with chloroform, followed by silica gel column chromatography, Sephadex LH-20 chromatography and reverse phase HPLC . Among these, pepticinnamin C showed the most potent inhibition (IC50-100 nM).

FEMS Microbiol Lett, 1993 Feb 1, 106(3), 233 - 7
Characterization of mutations that overcome the toxic effect of glucose on phosphoglucose isomerase less strains of Saccharomyces cerevisiae; Gamo FJ et al.; Glucose inhibits growth of yeast phosphoglucose isomerase mutants in permissive media . Mutants insensitive to this effect were isolated by selection on media containing 2% fructose + 2% glucose . A nuclear, monogenic, recessive mutation named rgl was responsible for this phenotype . The mutants isolated belonged to two complementation groups and have been termed rgl1 and rgl2 . When the double mutants were grown on fructose, fermentation of fructose or glucose was similar to that of the parental pgi strain but was not measurable when grown on fructose+glucose . Under these conditions, respiration of glucose and to a lesser extent of fructose was enhanced . The double mutants pgi rgl did not grow on fructose+glucose in the presence of antimycin A or ethidium bromide and their cytochrome oxidase was no longer sensitive to glucose repression . The results are interpreted as an indication that in the double mutants the glucose may be channeled through the pentose phosphate pathway to respiration.

J Dairy Sci, 1993 Feb, 76(2), 514 - 24
Effects of supplemental protein source on intraruminal fermentation, protein degradation, and amino acid absorption; Keery CM et al.; Cannulated steers were used to determine the effects of supplemental soybean meal, heated soybean meal, fish meal, and a combination of fish meal, heated soybean meal, and corn gluten meal on intraruminal protein degradation and absorption of AA from the small intestine . Organic matter digestion in the reticulo-rumen was greater in steers fed diets supplemented with soybean meal, but whole tract digestibility was not affected by protein source . Total and bacterial CP flows to the abomasum were lower in steers fed diets supplemented with fish meal than in steers fed diets supplemented with heated soybean meal or the combination supplement . Dietary CP flow was 33.5% higher in steers fed diets supplemented with heated soybean meal than in steers fed diets supplemented with soybean meal, fish meal, or the combination supplement . Less essential and nonessential AA flowed to the abomasum and were absorbed from the small intestine of steers receiving diets supplemented with soybean meal . Digestibility of small intestine AA was 21.9% lower in steers receiving the soybean meal treatment . Abomasal flows of Met and Thr and absorption of Lys, Met, and Thr were increased in steers fed diets containing heated soybean meal, fish meal, and the combination supplement . These results suggest that the supply of AA deficient in microbial CP (Lys, Met, and Thr) can be increased and that absorbed AA balance can be changed markedly by selection of rumen escape protein supplements.

An Esp Pediatr, 1993 Feb, 38(2), 107 - 12
{Relationship between primary lactose malabsorption and consumption of dairy products}; Escribano Subias J et al.; This study was designed to determine the influence of lactose malabsorption on the consumption of dairy products . We studied 157 children and 43 adults . The Breath-hydrogen test was used to define their level of lactose digestion . The prevalence of lactose maldigesters was 12% . We found a large relationship between the consumption of milk and milk products and age . Malabsorbers consumed more fermented dairy products (ripened cheese and yogurt) than did absorbers (p < 0.05) . Subjects with normal lactose absorption consumed more milk, butter, cream cheese and global lactose than the maldigesters (p < 0.05) . Lactose intolerance, familiar consumption and geographic origins had little influence on an individual's consumption habits.

Appl Environ Microbiol, 1993 Feb, 59(2), 405 - 9
Inhibition of ruminal cellulose fermentation by extracts of the perennial legume cicer milkvetch (Astragalus cicer); Weimer PJ et al.; Cicer milkvetch (Astragalus cicer L.) is a perennial legume used as a pasture or rangeland plant for ruminants . A study was undertaken to determine whether reported variations in its ruminal digestibility may be related to the presence of an antinutritive material . In vitro fermentation of neutral detergent fiber (NDF) of cicer milkvetch by mixed rumen microflora was poorer than was the fermentation of NDF in alfalfa (Medicago sativa L.) . Fermentation of cicer milkvetch NDF was improved by preextraction of the ground herbage with water for 3 h at 39 degrees C . Such water extracts selectively inhibited in vitro fermentation of pure cellulose by mixed ruminal microflora and by pure cultures of the ruminal bacteria Ruminococcus flavefaciens FD-1 and Fibrobacter succinogenes S85 . Inhibition of the cellulose fermentation by mixed ruminal microflora was dependent upon the concentration of cicer milkvetch extract and was overcome upon prolonged incubation . Pure cultures exposed to the extract did not recover from inhibition, even after long incubation times, unless the inhibitory agent was removed (viz., by dilution of inhibited cultures into fresh medium) . The extract did not affect the fermentation of cellobiose by R . flavefaciens but did cause some inhibition of cellobiose fermentation by F . succinogenes . Moreover, the extracts did not inhibit hydrolysis of crystalline cellulose, carboxymethyl cellulose, or p-nitrophenylcellobioside by supernatants of these pure cultures of cellulolytic bacteria or by a commercial cellulase preparation from the fungus Trichoderma reesei . The agent caused cellulose-adherent cells to detach from cellulose fibers, suggesting that the agent may act, at least in part, by disrupting the glycocalyx necessary for adherence to, and rapid digestion of, cellulose.

Biotechniques, 1993 Feb, 14(2), 228 - 33
An autosampler for fermentation; Page WJ et al.; The operation of an autosampler, constructed from a peristatic pump, an interval timer and a fraction collector, for the removal of whole broth fermentation samples is described . The autosampler repetitively removes samples of user-determined size at repetitive time intervals . The sampler is intended for use with low containment fermentations . A comparison of the autosampler and the manual sampler of a fermenter showed good correlation of substrate consumption rates when changes were sizeable and superior results were obtained with the autosampler when the changes were subtle during a typical diauxic fermentation of Azotobacter vinelandii.

J Nutr, 1993 Feb, 123(2 Suppl), 418 - 23
Colon cancer--do the nutritional epidemiology, the gut physiology and the molecular biology tell the same story?
Potter JD.
Colon carcinogenesis models exist at epidemiologic, physiologic and molecular biologic levels . Thinking about the coherence of such models is useful both to inform colon cancer research and because the reasoning process may be generalizable . The consistent epidemiologic risk factors are low vegetable/fiber and high fat/meat/protein intakes . Others include physical activity, alcohol and reproduction . These epidemiologic risk factors appear to map to physiologic variables that provide mechanistic explanations for the associations: higher bile acids, fiber fermentation and effects of specific anticarcinogens found in vegetables . The possibility that the meat/fat association is due to carcinogens or promoters produced in cooked foods adds complexity to the physiologic model . As a link across genetics, physiology and epidemiology, the role of acetylator status is considered . Finally, whether relationships might exist between the epidemiologic/physiologic risk factors and the recently described molecular genetic changes and other colon cancer molecular mechanisms is considered.

Protein Expr Purif, 1993 Feb, 4(1), 52 - 8
A purification method for labile variants of ribonuclease T1; Mayr LM et al.; We present a new procedure for the rapid production of ribonuclease T1 variants with decreased stability which could not be purified in satisfying amounts by the existing methods . The major changes from the established procedures are the following . (i) The cells were grown at 28 degrees C rather than at 37 degrees C . (ii) The entire purification was performed at low temperatures (4 degrees C) . (iii) Materials for chromatography with high flow rates were used to accelerate protein isolation . (iv) The pH was lowered from 7.5 to 6.0, a condition under which RNase T1 is much more stable . The use of this improved procedure allowed the purification of the labile P39G and P73V variants of RNase T1 . By the same technique 300 mg of the wild-type protein could be isolated from 10 liters liquid culture within 3 days . The P39G and the P73V mutations strongly decrease the stability of RNase T1 and the midpoints of the reversible thermal unfolding transition are lowered by 16 and 6 degrees C, respectively, relative to that of the wild-type protein . The decrease in temperature during fermentation and the rapid purification at low temperature and under solvent conditions where the stability of the proteins is high are probably the major reasons for the dramatic increase in yield of these labile variants of RNase T1 . Such an approach should be valuable for the production of recombinant proteins in general.

J Bacteriol, 1993 Feb, 175(3), 870 - 8
Anaerobic regulation of the adhE gene, encoding the fermentative alcohol dehydrogenase of Escherichia coli; Leonardo MR et al.; The regulation of the adhE gene, which encodes the trifunctional fermentative acetaldehyde-alcohol dehydrogenase of Escherichia coli, was investigated by the construction of gene fusions and by two-dimensional protein gel electrophoresis . Both operon and protein fusions of adhE to lacZ were induced 10- to 20-fold by anaerobic conditions, and both fusions were repressed by nitrate, demonstrating that regulation is at the level of transcription . Nitrate repression of phi (adhE-lacZ) expression, as well as of alcohol dehydrogenase enzyme activity, was partly relieved by a mutation in narL . Mutations in rpoN or fnr had no effect on the expression of adhE . Two-dimensional protein gels demonstrated that increases in the amount of adhE protein correlated with increases in enzyme activity, demonstrating that induction was due to synthesis of new protein, not to activation of preexisting protein . When oxidized sugar derivatives such as gluconate or glucuronate were used as carbon sources, the anaerobic expression of phi (adhE-lacZ) was greatly reduced, whereas when sugar alcohols such as sorbitol were used, the expression was increased compared with expression when glucose was the carbon source . This observation suggested that induction of phi (adhE-lacZ) might depend on the level of reduced NADH, which should be highest with sorbitol-grown cells and lowest with glucuronate-grown cells . When phi (adhE-lacZ) was present in a strain deleted for the adhE structural gene, anaerobic expression of phi (adhE-lacZ) was approximately 10-fold higher than in an adhE+ strain . Since the presence of alcohol dehydrogenase would serve to decrease NADH levels, this finding again implies that the adhE gene is regulated by the concentration of reduced NAD . Introduction of a pgi (phosphoglucose isomerase) mutation reduced the anaerobic induction of phi(adhE-lacZ) when the cells were grown on glucose, but had little effect on fructose-grown cells . Pyruvate did not overcome the pgi effect, but glycerol 3-phosphate did, which is again consistent with the possibility that adhE expression responds to the level of reduced NAD rather than to a glycolytic intermediate.

J Antibiot (Tokyo), 1993 Feb, 46(2), 207 - 13
SCH 45752--an inhibitor of calmodulin-sensitive cyclic nucleotide phosphodiesterase activity; Hegde VR et al.; A highly potent inhibitor of calmodulin-sensitive phosphodiesterase (PDE) activity was isolated from the culture broth of an unidentified fungal isolate, SCF-125 . A chemically defined medium was developed for production of this compound . The PDE inhibitor was isolated from the fermentation filtrate by adsorption on a macro-reticular resin and further purified by gel filtration chromatography and reverse-phase HPLC . The major PDE inhibitor was identified as cephalochromin, a bis-naphthopyrone, by spectral data analysis . The compound, SCH 45752, inhibited calmodulin-sensitive PDE activities with IC50 values of 40-47 nM . It inhibited the activities of calmodulin-independent PDE and various protein kinases with higher IC50 values (2-40 microM) . SCH 45752 does not appear to be a calmodulin antagonist . Furthermore, SCH 45752 affects smooth muscle contraction at a concentration of 30 microM; it potentiated the relaxing effect of sodium nitroprusside on carotid artery media contracted by histamine . Thus SCH 45752 is one of the most potent inhibitors of calmodulin-sensitive PDE activity known, and it is capable of exerting a pharmacological effect in at least one intact tissue model.

Eur J Biochem, 1993 Feb 1, 211(3), 697 - 702
Cloning, sequencing and expression of the gene encoding the carboxytransferase subunit of the biotin-dependent Na+ pump glutaconyl-CoA decarboxylase from Acidaminococcus fermentans in Escherichia coli; Bendrat K et al.; 1 . The primary sodium-ion pump glutaconyl-CoA decarboxylase (GCD) from Acidaminococcus fermentans is composed of four subunits: GCDA, the carboxytransferase (65 kDa), GCDB, the carboxylyase (36 kDa), GCDC, the biotin carrier (24 kDa) and GCDD (14 kDa) of unknown function . A genomic library of A . fermentans was screened with an antiserum raised against whole GCD . A clone giving the strongest reaction in an immunoassay contained a 12-kbp genomic fragment from A . fermentans and was analysed further . An oligonucleotide deduced from the N-terminus of GCDA was used for probing the corresponding gene gcdA . It is 1761 bp in length and encodes for a protein of 64.3 kDa . Both partial amino acid sequences obtained from GCDA, the N-terminus as well as an internal tryptic peptide, were detected in the open reading frame (ORF) of gcdA . 2 . Sequencing of the flanking regions revealed three adjacent ORF (ORF1-3) which do not code for any of the peptide sequences known of the other GCD subunits . The ORF downstream of gcdA (ORF3) is followed by hgdA and hgdB coding for 2-hydroxyglutaryl-CoA dehydratase, the preceding enzyme of the pathway of glutamate fermentation . Our results suggest that at least these three genes of the hydroxyglutarate pathway are organised in an operon and that the genes of the other GCD subunits from which peptide sequences are known (GCDB and GCDC) are not located adjacent to gcdA . 3 . gcdA was amplified from genomic DNA using the polymerase chain reaction and cloned into the expression vector pJF118HE . Active GCDA subunit (up to 2.8 nkat/mg protein), catalysing the biotin-dependent formation of crotonyl-CoA from glutaconyl-CoA, was obtained in cell-free extracts of Escherichia coli DH5 alpha by moderately inducing the tac promoter of pJF118HE with 25-100 microM isopropyl-1-thio-beta-D-galactoside . Strong induction (1 mM isopropyl-1-thio-beta-D-galactoside) led to the formation of inclusion bodies from which GCDA could not be reactivated . The apparent Km = 51 mM for free biotin of the expressed GCDA subunit with V = 1.9 nkat/mg protein is similar to that of butanol-treated GCD composed of GCDA and GCDC (apparent Km = 40 mM) . Biocytin was found to be a somewhat better carboxy acceptor for the expressed GCDA subunit (apparent Km = 13 mM; V = 1.0 nkat/mg protein) . 4 . Native GCD and expressed GCDA were treated with 2 mM N-ethylmaleimide showing different kinetics of inactivation: GCD lost half of its activity within 6 min, whereas expressed GCDA required 21 min.

J Nutr, 1993 Feb, 123(2), 244 - 52
Viscosity and fermentability as attributes of dietary fiber responsible for the hypocholesterolemic effect in hamsters; Gallaher DD et al.; The attribute(s) of soluble dietary fibers responsible for cholesterol lowering is currently uncertain . A series of experiments were conducted in which viscosity and fermentability was assessed independently for their effect on plasma and liver cholesterol concentration . Hamsters were divided into four dietary groups and fed diets containing 0.12% cholesterol and 5% fiber as high viscosity hydroxypropyl methylcellulose (HV-HPMC group), low viscosity hydroxypropyl methylcellulose (LV-HPMC group), high viscosity guar gum (HV-GG group) or low viscosity guar gum (LV-GG group) . Hydroxypropyl methylcellulose is essentially nonfermentable, whereas guar gum is highly fermentable . Plasma cholesterol concentrations at 3, 6 and 11 wk and liver cholesterol concentrations at 6 and 11 wk were significantly lower in the HV-HPMC group relative to the LV-HPMC group (P < 0.05) . Intestinal content viscosities of the LV-HPMC and HV-GG groups were similar; consequently, these two groups were compared to examine the independent effect of fermentation . Plasma and liver cholesterol were significantly lower in the HV-GG group compared with the LV-HPMC group at 6 wk (P < 0.05), but not at 3 or 11 wk . Hepatic sterol synthesis rates were not affected by any of the diets . This study shows that greater viscosity of intestinal contents is strongly associated with cholesterol reduction, but that the contribution of fiber fermentation remains uncertain.

Microbiologia, 1993 Feb, 9 Spec No, 76 - 82
{Utilization of molecular techniques for the characterization of wine yeasts and the study of the wine-making process}; Querol A et al.; The study of the fermentation process in the Alicante region allowed us to conclude that adverse climatic conditions could be responsible for deficient wine-making with serious problems arising fermentations, usually causing incomplete fermentation . In order to avoid these problems, we selected a Saccharomyces cerevisiae strain, namely T73, isolated in the same Alicante region, to be used to perform controlled fermentations . The use of selected strains in the wine-making process requires the development of characterization techniques that can clearly differentiate between the inoculated strain and the wild strains present in the musts . In order to differentiate strains present in the wine ecosystems, an extensive survey of different methods of yeast strains identification has been carried out . However, these techniques are very complex to be used in industry . For this reason, we have developed a new, simple, inexpensive and rapid method based on mitochondrial DNA restriction analysis . This technique was applied to the control of wine fermentations conducted by active dry yeasts . This molecular approach allows us to understand the role of the inoculated dry yeast strain and that of the natural S . cerevisiae flora during wine fermentation.

Comp Biochem Physiol Comp Physiol, 1993 Feb, 104(2), 357 - 60
Changes in food intake with ambient temperature alter hindgut fermentation in the damara mole-rat Cryptomys damarensis; Yahav S et al.; 1 . Changes in food consumption and fermentation capacity were examined in mole-rats housed at 23 and 30 degrees C . 2 . At both temperatures animals maintained body mass . Food consumption was lower at the higher temperature and led to a similar decline in caecal mass . 3 . Caecal dry matter content and fermentation efficiency were unaffected by food intake . However, gas production per animal decreased markedly with the reduced food intake . 4 . The drop in fermentation in response to decreased food intake led to a concomitant decrease in heat production . This would be highly advantageous for chthonic rodents residing during summer in warm humid plugged burrows.

J Ind Microbiol, 1993 Feb, 12(2), 99 - 102
The effect of cerulenin on the production of esperamicin A1 by Actinomadura verrucosospora; Lam KS et al.; Addition of cerulenin (0.25-1.0 mM) to cultures of Acinomadura verrucosospora before the onset of esperamicin synthesis inhibited the production of esperamicin A1 by the microorganism . This result indicates that esperamicin A1 is biosynthesized in part by the polyketide pathway . Addition of cerulenin to the cultures during the active production phase led to a net decrease in esperamicin A1 production . The 14C-acetate labeling pattern of esperamicin A1 in the cultures with or without addition of cerulenin at the active production phase also demonstrated the instability of esperamicin A1 in the fermentation . This suggests that esperamicin A1 is unstable and degradation occurs during the active production phase . Addition of the neutral resin Diaion HP-20 (1%) to the fermentation enhanced the production of esperamicin A1 by 53%.

J Ind Microbiol, 1993 Feb, 11(2), 95 - 103
Improvement in the titer of echinocandin-type antibiotics: a magnesium-limited medium supporting the biphasic production of pneumocandins A0 and B0; Tkacz JS et al.; We have developed a liquid fermentation medium for the submerged culture of the fungus, Zalerion arboricola, which supports the rapid production of an echinocandin-type antibiotic, pneumocandin A0 (formerly L-671,329), in yields increased at least 4-fold over those reported previously . The improvements were achieved through medium simplification, substitution of high levels of mannitol for glycerol as the major source of carbon, and restriction of available magnesium . Antibiotic formation in batch cultures with this mannitol-based medium is not confined to the idiophase; rather production appears to be biphasic, with synthesis beginning during growth (i.e., at day 3) and increasing in rate at day 11, well after rapid growth has ended . Accumulation of antibiotic continues beyond 14 days, and by 21 days titers greater than 500 micrograms/ml are attained . For the synthesis of a related compound, pneumocandin B0, by a mutant strain of Z . arboricola, the medium gives similar production kinetics and a titer of 800 micrograms/ml . Although supplementation of the medium with magnesium ions stimulates growth, it decreases titer by preferentially affecting the second phase of antibiotic synthesis . This decline in synthesis in the magnesium-supplemented medium is explained by the depletion of mannitol before the second phase of synthesis can begin . In contrast, mannitol in the magnesium-limited medium is used more slowly with approximately half still available at day 11 to support continued antibiotic formation.

Biotechnology (N Y), 1993 Feb, 11(2), 207 - 12
A novel process for the large-scale purification of recombinant tick anticoagulant peptide using perfusion chromatography; Lehman ED et al.; Tick anticoagulant peptide (TAP) is a 60 amino acid peptide (Mr = 6977, pI = 4.9) found in the saliva of the soft tick Ornithodorous moubata that specifically inhibits blood coagulation factor Xa (fXa) . A recombinant form of TAP (rTAP) secreted by Saccharomyces cerevisiae was purified from 200 liters of fermentation broth with POROS, strong cation exchange (SCX) and reversed-phase high performance liquid perfusion chromatography (RP-HPLC) media (20 microns nominal particle diameter) . The higher linear flow rates and dynamic capacities, as well as low back pressures, obtained with perfusion chromatography media permitted 37.5 g of rTAP to be efficiently captured and significantly enriched from 400 liters of diafiltered fermentation broth (24.3 g yield) with 1.25 liter of SCX media using a low pressure column and peristaltic pump in 4.5 hours . Subsequently, 16.7 g of rTAP obtained from the capture step was purified in a high-resolution mode with the same SCX media, after the media was cleaned and repacked into an 800 ml high-pressure column . By doing multiple rapid cycles at high linear flow rates, preparative-scale high-resolution purification of multi-gram amounts of the peptide was done on this relatively small column in only 10.5 hours . Finally, the peptide was desalted and decolorized on a 200 ml RP-HPLC column of perfusion chromatography media by doing multiple rapid cycles . After lyophilization, 12 g of peptide (46.9% yield) was obtained that was > 96% homogeneous by several analytical criteria and fully active in inhibiting blood coagulation factor Xa (fXa).(ABSTRACT TRUNCATED AT 250 WORDS)

J Biol Chem, 1993 Jan 25, 268(3), 1824 - 9
Cloning and sequencing of a cDNA encoding Saccharomyces cerevisiae carnitine acetyltransferase . Use of the cDNA in gene disruption studies; Kispal G et al.; cDNA encoding for carnitine acetyltransferase (CAT) of yeast S . cerevisiae was isolated by screening a yeast cDNA lambda gt11 library with antibody . The whole coding sequence was obtained from the cDNA and from a YEP 13 DNA clone identified using the cDNA as probe . The coding sequence consists of 670 residues, which amounts to a molecular mass of 77,300 kDa . This cDNA was used successfully to disrupt the gene for the mitochondrial isoenzyme of CAT, which was shown by measuring the enzyme activity and by immunoblot . The acetylcarnitine content of these cells decreased significantly . A search in the PIR protein data base revealed that besides the known carnitine acyltransferases, choline acyltransferases are highly homologous to yeast CAT . The mitochondrial CAT-deficient (CAT-) cells were able to grow on different fermentable and nonfermentable carbon sources, even on acetate at the same rate as the parental strain . In contrast to these, 13C NMR studies revealed significant differences between parental and CAT- cells . In CAT-cells {3-13C}pyruvate was converted mainly to lactate and acetate, whereas in the parental cells alanine and tricarboxylic acid cycle intermediates were found as the main products of pyruvate metabolism beside acetate . These results suggest diminished flux through the pyruvate dehydrogenase complex in the absence of mitochondrial CAT in yeast cells.

FEMS Microbiol Lett, 1993 Jan 15, 106(2), 201 - 4
Mycoplasma cells stimulate in vitro activation of plasminogen by purified tissue-type plasminogen activator; Tarshis M et al.; In an in vitro direct assay with tissue-type plasminogen activator (tPA), plasminogen and the chromogenic substrate S-2251, the ability of Mycoplasma fermentans KL4 to stimulate tPA-mediated activation of plasminogen to plasmin was studied . Mycoplasma cells markedly enhanced the activation of plasminogen by tPA in a concentration-, temperature- and pH-dependent manner . Nonidet P-40 (0.01%), sonication, and freezing and thawing of the cells substantially increased the stimulatory effect of mycoplasma on tPA activity . In contrast, the activation of plasminogen by urokinase was refractory to mycoplasma cells . The mycoplasma-mediated stimulation of tPA activity was prevented by epsilon-aminocaproic acid (EACA), a lysine analogue known to block lysine-binding sites (LBS) in plasminogen and tPA . Among several Mycoplasma fermentans strains tested, incognitus strain demonstrated the highest stimulation activity . These results suggest that mycoplasma cells interact with LBS in tPA and plasminogen to enhance plasminogen activation.

Biochim Biophys Acta, 1993 Jan 15, 1161(1), 19 - 27
Purification and characterization of pyruvate ferredoxin oxidoreductase from the hyperthermophilic archaeon Pyrococcus furiosus; Blamey JM et al.; Pyrococcus furiosus grows optimally at 100 degrees C by carbohydrate fermentation . It is thought to contain a novel tungsten-dependent, NAD(P)-independent glycolytic pathway in which one of the oxidation steps is catalyzed by a tungsten-containing aldehyde ferredoxin oxidoreductase . The enzyme that catalyzes the terminal oxidation step, pyruvate ferredoxin oxidoreductase (POR), has now been purified . POR has a molecular mass of 100 kDa and is comprised of three subunits (45, 31 and 24 kDa) . It lacks tungsten but contains thiamine pyrophosphate (TPP) and two ferredoxin-type {4Fe-4S} clusters per molecule which, by EPR spectroscopy, can be differentiated by their relaxation properties . The enzyme requires CoASH but not TPP for pyruvate oxidation activity and will not use 2-oxoglutarate, phenyl pyruvate or indole pyruvate as substrates . POR is virtually inactive at 25 degrees C and shows a temperature optimum for pyruvate oxidation above 90 degrees C . The apparent Km values for pyruvate, CoASH and P . furiosus ferredoxin at 80 degrees C are 460, 100 and 70 microM, respectively . Carbon monoxide was a potent inhibitor of pyruvate oxidation (apparent Ki = 7 microM) . The half-life of activity (t50%) in air at 25 degrees C was 15 min and the t50% value at 80 degrees C (under anaerobic conditions) was 23 min . Based on molecular comparisons with PORs from mesophilic organisms, it is proposed that P . furiosus POR may represent an ancestral form of a pyruvate-oxidizing enzyme.

Ugeskr Laeger, 1993 Jan 4, 155(1), 30 - 2
{A stink bomb in an office environment . Sick building syndrome with toxic rhinitis after exposure to fusel}; Hein HO et al.; In 1983 WHO, defined "The Sick Building Syndrome" . Various conditions influence the indoor climate, among others the degassing of chemicals . An epidemic of sick building syndrome is described in a two year old office building . The symptoms appeared after exposure to toxic chemicals released by a stink bomb--a form of exposure not previously described in the literature . Gas chromatographic analysis of the content of the stink bomb revealed 22 different chemicals likely to be remains from an alcoholic fermentation process . Twenty-four employees were exposed . A questionnaire investigation of the employees revealed that seven had symptoms related to the exposure . A clinical investigation of those who claimed to have symptoms took place . Six of the seven patients were investigated . They all had toxic rhinitis with bleeding . Owing to an unsystematic procedure it took more than two months before the indoor climate was normalized . The toxic rhinitis and other symptoms gradually decreased over more than four months . In order to minimize potential health damage due to the sick building syndrome, we recommend that experts should be consulted within this particular field.

Arch Tierernahr, 1993, 43(1), 79 - 90
{Ruminal nitrogen metabolism in calves and sheep . 3 . Effect of hay-concentrate ratio in calves}; Boldt E et al.; During the milk feeding period (ca . 55th day of life) and 2 weeks after the milk feeding period (ca . 80th day of life) the influence of a hay quota in the ration (on DM basis) of 6, 10, 14 and 18% in the milk feeding period and of 16, 23, 31 and 37% in the period after milk feeding was tested as to ruminal N metabolization with calves supplied with duodenal re-entrant cannulae . The increase of the hay quota in the ration for ruminating calves reduced as a tendency duodenal NAN passage, its bacterial N-quota, post-ruminal NAN digestibility and, due to a worse utilization of available N for bacterial N-synthesis, bacterial N-synthesis rate . The apparent fermentation of organic matter was, as a tendency, increased with the growing hay quota in the ration.

Vet Med (Praha), 1993, 38(4), 229 - 35
{The effect of cadmium on indicators of rumen fermentation and their levels in biological material in sheep}; Sviatko P et al.; The experiment was carried out with three groups, each consisting of six adult sheep of the Merino breed weighing 40-45 kg, fed with the diet composed of 1 kg of meadow hay and an addition of 0.2 kg of barley meal for 3 weeks before the experiment . The first group - the control - was provided the natural supply 0.09 mg Cd/kg DM of the diet, the supply of Ist experimental group was increased by 5 mg Cd/kg DM and of the IInd experimental group by 10 mg Cd/kg of diet DM in the form of sulphate . The influence of mentioned cadmium doses on levels of volatile fatty acids, their energetic yield and proportion of their energy and energy of methane and bacterial mass from the energy of fermented feed hexose, as well as the total number of infusoria and number of infusoria of Entodinium sp . in the ruminal fluid of sheep with an increased supply of cadmium were examined during seven weeks . In addition to that cadmium contents in the liver, kidneys, muscles, excrements and ruminal fluid was investigated . Obtained results indicate that yet a lower supply of cadmium amounting to 5 mg and 10 mg/kg DM of the sheep diet, had significant negative influence (Tab . I) on the production of isobutiric acid in rumen fluids and decreased significantly (Tab . III) the total counts of infusoria and number of Entodinium sp . infusoria in the rumen fluids of sheep.(ABSTRACT TRUNCATED AT 250 WORDS)

Nahrung, 1993, 37(2), 141 - 6
Effect of rabadi fermentation on phytic acid and in vitro digestibility of barley; Gupta M et al.; Rabadi, an indigenous fermented food, was prepared by mixing cereal flour with buttermilk, allowing it to ferment at 30, 35 and 40 degrees C for 6, 12, 18, 24 and 48 h and cooking the fermented mixture for 0.5 h with continuous stirring . Two types of rabadi were prepared i.e . autoclaved and unautoclaved . In autoclaved type of rabadi cereal flour was mixed with water, autoclaved (0.103 MPa = 15 psi for 15 min), cooled, mixed with buttermilk and fermented . As this type of rabadi was precooked prior to fermentation, hence, the fermented product did not require cooking afterwards, while in unautoclaved rabadi, barley flour and buttermilk were mixed, fermented and then cooked prior to consumption . Phytic acid was reduced drastically at all the temperatures and periods of fermentation in both autoclaved and unautoclaved type of rabadi; greater reduction occurred at higher temperature and duration of fermentation . A significant improvement in the in vitro digestibility of starch and protein was observed; maximum improvement was noticed when fermentation was carried out at 40 degrees C for 48 h in both the types of rabadi . Phytic acid had a significant (P < 0.05) negative correlation with digestibility (in vitro) of proteins and starch of barley flour rabadi.

Schweiz Arch Tierheilkd, 1993, 135(4), 117 - 24
{The "hemorrhagic bowel syndrome" of swine: clinical, pathologo-anatomic and etiopathogenic aspects}; Hani H et al.; In an analysis of autopsy findings from 16,384 pigs (1980-90) 436 cases of haemorrhagic bowel syndrome (HBS) were found (2.66% of autopsies) . In most cases fattening pigs (in the weight of 25-100 kg) were affected . HBS was significantly more frequent in females . Intestinal volvulus was confirmed in 56.2% of all cases of HBS, however by more careful examination between 1988 and 1990 even in 80% of cases . In most cases the degree of torsion was 180 degrees and the direction as seen with the pig lying on its back was anticlockwise . Clinical history as reported by owners revealed limited information: sudden death of one or several pigs within three months, association with whey feeding not uncommon . Significantly more cases of HBS were seen during spring and on mondays . Numerous yeasts could be detected in mucosal impression smears of ileum, colon and caecum . Additional analyses in six farms suffering from big losses due to HBS suggested that several environmental and management factors may be involved pathogenetically: feeding only once a day of excessive amounts of a liquid diet, especially whey (a highly fermentable substrate), poor hygiene of liquid diets (high bacterial counts and yeast concentrations) . In mixed breeding and fattening units, the aforementioned factors could be responsible also for sudden deaths in dry sows caused by colonic bloat often associated with intestinal rupture and torsions of the stomach and/or the spleen.

Vopr Med Khim, 1993 Jan-Feb, 39(1), 45 - 7
{Comparative physico-chemical study of L-lysine-alpha-oxidase from surface and fermenter growth Trichoderma sp.}; Lukasheva EV et al.; Homogeneous preparations of L-lysine-alpha-oxidase were obtained from Trichoderma sp cultivated by using a surface technique and a fermenter set . The homogeneous enzyme preparations were similar in molecular mass, isoelectric point and substrate specificity . There was the single difference in the absorbance spectra, which may occur due to the presence of cofactor FAD in various oxidation states . The findings suggest that cultivation of Trichoderma sp in the fermenter set did not alter properties of L-lysine-alpha-oxidase produced.

Curr Genet, 1993, 23(4), 281 - 9
The growth and signalling defects of the ggs1 (fdp1/byp1) deletion mutant on glucose are suppressed by a deletion of the gene encoding hexokinase PII; Hohmann S et al.; Yeast cells defective in the GGS1 (FDP1/BYP1) gene are unable to adapt to fermentative metabolism . When glucose is added to derepressed ggs1 cells, growth is arrested due to an overloading of glycolysis with sugar phosphates which eventually leads to a depletion of phosphate in the cytosol . Ggs1 mutants lack all glucose-induced regulatory effects investigated so far . We reduced hexokinase activity in ggs1 strains by deleting the gene HXK2 encoding hexokinase PII . The double mutant ggs1 delta, hxk2 delta grew on glucose . This is in agreement with the idea that an inability of the ggs1 mutants to regulate the initiation of glycolysis causes the growth deficiency . However, the ggs1 delta, hxk2 delta double mutant still displayed a high level of glucose-6-phosphate as well as the rapid appearance of free intracellular glucose . This is consistent with our previous model suggesting an involvement of GGS1 in transport-associated sugar phosphorylation . Glucose induction of pyruvate decarboxylase, glucose-induced cAMP-signalling, glucose-induced inactivation of fructose-1,6-bisphosphatase, and glucose-induced activation of the potassium transport system, all deficient in ggs1 mutants, were restored by the deletion of HXK2 . However, both the ggs1 delta and the ggs1 delta, hk2 delta mutant lack detectable trehalose and trehalose-6-phosphate synthase activity . Trehalose is undetectable even in ggs1 delta strains with strongly reduced activity of protein kinase A which normally causes a very high trehalose content . These data fit with the recent cloning of GGS1 as a subunit of the trehalose-6-phosphate synthase/phosphatase complex.(ABSTRACT TRUNCATED AT 250 WORDS)

Reprod Nutr Dev, 1993, 33(1), 43 - 9
Effect of a viable yeast culture on digestibility and rumen fermentation in sheep fed different types of diets; Fiems LO et al.; Five mature wethers fitted with rumen fistulas were fed grass hay and a sugarbeet-pulp-based concentrate or maize silage and a cereal-based concentrate (50/50 digestible organic matter basis), or without with 5 g yeast supplement (Saccharomyces cerevisiae, Biosaf) per day in a latin square design . Diets were given for a 28-d adaptation period, followed by a 10-d collection period to determine digestibility and nitrogen retention data . Afterwards, rumen samples were taken on 3 consecutive days and analysed for volatile fatty acids, pH and ammonia . Digestibility and nitrogen balance were not affected by yeast treatment . Supplementation of yeast increased acetate: propionate ratio, butyrate, isoacids, pH and ammonia . The effects were more pronounced for the maize silage diet . These results demonstrate that the effect of yeast culture on rumen fermentation may depend on the nature of the diet . Living yeast cell number in the rumen fluid rapidly declined when dietary yeast was ceased . Furthermore, yeast cells survived the passage through the digestive tract.

Mikrobiol Zh, 1993 Jan-Feb, 55(1), 12 - 8
{The isolation and purification of a nonspecific DNAse from Mycoplasma fermentans PG-18}; Sitailo SZ et al.; Nonspecific endogenic DNAase has been isolated from biomass of Mycoplasma fermentans PG-18 cells and purified to the homogeneous state . The scheme of isolation consists of purification stages on columns with phosphocellulose, DNA-cepharose CL-8B and phenylcepharose . DNAase was not bound to phosphocellulose, its volume was equal to zero . Then this DNAase was passed through column with DEA-cepharose CL-6B (elution by gradient KCl from 0.1 to 1.8M): enzyme was eluted at KCl concentration in the eluting buffer from 0.1 to 1.2 M . The enzyme was purified to the homogeneous state on column with phenylcepharose (elution by linear gradient of ethylene glycol from 30 to 80%): enzyme was eluted at the concentration of ethylene glycol in the eluting buffer from 43 to 80% . According to data obtained using gel-electrophoresis, under the denaturing conditions molecular mass of enzyme in acrylamide gel was 34 kDa.

Yeast, 1993 Jan, 9(1), 85 - 94
Yeast flocculation: flocculation onset and receptor availability; Stratford M; Flocculent strains of brewing yeast grow and ferment as single cells and flocculate in the stationary phase of growth . The switch from single-celled yeast growth to multi-celled aggregation, flocculation onset, is of critical importance to the brewing industry . Yeast flocculation involves adhesion of surface-lectins on flocculent cells to carbohydrate receptors on neighbouring cell-walls . The presence of carbohydrate receptors, outer-chain mannan side-branches, was monitored throughout growth of flocculent and non-flocculent strains of Saccharomyces cerevisiae, with particular attention to the growth phases where flocculation is normally developed . Receptors were probed by coflocculation with flocculent strains and by aggregation with concanavalin A, a lectin shown to use the same receptors as flocculation . While considerable variation was found in coflocculation and concanavalin A aggregation between strains, little or no change in receptor availability was found throughout the growth of all yeast strains . Yeast cells could easily be coflocculated at any growth stage . It was concluded that receptor availability is not involved in the process of flocculation onset.

Can J Microbiol, 1993 Jan, 39(1), 61 - 9
Changes in the rumen microbial population and its activities during the refaunation period after the reintroduction of ciliate protozoa into the rumen of defaunated sheep; Williams AG et al.; Changes in the microbial populations, their activities, and the ruminal fermentation were monitored for 50 d following the reintroduction of ciliate protozoa into four defaunated sheep . A protozoal population was reestablished successfully in each recipient, using a washed inoculum containing approximately 10(3) cells, although there were between-animal differences in the rates of recolonization and genus establishment . Entodinium spp . predominated in the initial stages of the refaunation period and had an apparent maximal generation time of 9-10 h . Bacterial and fungal numbers did not decline following the reintroduction of protozoa and a small transient increase in the numbers of amylolytic and xylanolytic bacteria and fungal zoospores occurred in the early stages of refaunation when the protozoal population was < 10(5)/g ruminal contents, but these subsequently declined as the protozoa established . Although the fibrolytic bacterial population was lowest in period 3 (> 10(5) protozoa/g), the in sacco ruminal digestion of Lolium perenne hay and polysaccharolytic enzyme activities in the solids-associated populations were either maintained or increased when protozoa were present confirming the important contribution of protozoa to fibre breakdown in the rumen . Significant changes in ruminal microbial activities occurred after protozoal reinoculation but before the rumen had refaunated completely . Arylamidase activities in the liquor-phase population and ruminal ammonia concentrations increased significantly within 48 h of transfaunation; the magnitude of the effects became more pronounced as the protozoal population developed . However, volatile fatty acid formation and ruminal pH were not affected after the reintroduction of protozoa.

Arch Microbiol, 1993, 159(2), 174 - 81
Purification of glutaryl-CoA dehydrogenase from Pseudomonas sp., an enzyme involved in the anaerobic degradation of benzoate; Hartel U et al.; Cell-free extracts of Pseudomonas sp . strains KB 740 and K 172 both contained high levels of glutaryl-CoA dehydrogenase when grown anaerobically on benzoate or other aromatic compounds and with nitrate as electron acceptor . These aromatic compounds have in common benzoyl-CoA as the central aromatic intermediate of anaerobic metabolism . The enzymatic activity was almost absent in cells grown aerobically on benzoate regardless whether nitrate was present . Glutaryl-CoA dehydrogenase activity was also detected in cell-free extracts of Rhodopseudomonas, Rhodomicrobium and Rhodocyclus after phototrophic growth on benzoate . Parallel to the induction of glutaryl-CoA dehydrogenase as measured with ferricenium ion as electron acceptor, an about equally high glutaconyl-CoA decarboxylase activity was detected in cell-free extracts . The latter activity was measured with the NAD-dependent assay, as described for the biotin-containing sodium ion pump glutaconyl-CoA decarboxylase from glutamate fermenting bacteria . Glutaryl-CoA dehydrogenase was purified to homogeneity from both Pseudomonas strains . The enzymes catalyse the decarboxylation of glutaconyl-CoA at about the same rate as the oxidative decarboxylation of glutaryl-CoA . The green enzymes are homotetramers (m = 170 kDa) and contain 1 mol FAD per subunit . No inhibition was observed with avidin indicating the absence of biotin . The N-terminal sequences of the enzymes from both strains are similar (65%).

Arch Microbiol, 1993, 159(2), 109 - 13
Complete oxidation of benzoate and 4-hydroxybenzoate by a new sulfate-reducing bacterium resembling Desulfoarculus; Drzyzga O et al.; A new sulfate-reducer "strain SAX" was isolated from an anaerobic marine sediment {Saxild, Denmark} . The isolate was a gram-negative, motile and non-spore-forming rod which sometimes appeared as a curved rod . Strain SAX differed from all described Desulfovibrio-, Desulfobotulus- and Desulfoarculus-species by the ability to degrade aromatic compounds such as benzoate, 4-hydroxybenzoate and phenol completely to CO2 . Electron donors used included lactate, pyruvate, malate, fumarate, crotonate and butyrate, while pyruvate was fermented in the absence of an external electron acceptor . Sulfate, thiosulfate or sulfite served as electron acceptors with benzoate as the donor, while nitrate and nitrite did not . The sulfate-reducing bacterium required vitamins and NaCl-concentrations of about 20 g/l . The optimum temperature for growth of strain SAX was 30 degrees C and the optimum pH value was 7.3 . The DNA base composition was 62.4 mol% G+C . The strain possessed cytochrome c3, but no desulfoviridin . On the basis of these characteristics and because strain SAX could not be ascribed to any of the existing species therefore assignment as a new species to the genus Desulfoarculus was suggested.

Appl Environ Microbiol, 1993 Jan, 59(1), 290 - 5
Cobalamin-mediated mercury methylation by Desulfovibrio desulfuricans LS; Choi SC et al.; The prominence of sulfate reducers in mercury biomethylation prompted the examination of the methyl carrier and mercury methylation activity of Desulfovibrio desulfuricans LS . There was a low degree of mercury tolerance and a high degree of methylation during fermentative growth; the opposite was true during sulfate reduction . During 2 days of fermentative growth, up to 37% of HgCl2 was methylated at 0.1 micrograms/ml, but only 1.5% was methylated at 10.0 micrograms/ml . Less than 1% of the added HgCl2 was methylated under sulfate-reducing conditions . D . desulfuricans LS radioimmunoassay results were positive for cobalamin . The addition of CoCl2 and benzimidazole to fermentative cultures increased methylation activity . From D . desulfuricans LS grown in the presence of (57)CoCl2, a corrinoid was extracted and purified . High-performance liquid chromatography analysis of the purified extract yielded a single peak with the retention time of cobalamin, and 97% of the (57)Co radioactivity was associated with this peak . Fast atom bombardment and UV and visible spectra of the isolated corrinoid matched those of cobalamin . When methylated with (14)CH3I, the isolated corrinoid methylated Hg(2+) with a 93.9% preservation of (14)C specific activity . We conclude that D . desulfuricans LS methylates mercury via cobalamin (vitamin B12) . Under physiological conditions, the enzymatic catalysis of this reaction is likely.

Appl Environ Microbiol, 1993 Jan, 59(1), 255 - 9
Presence of lactate dehydrogenase and lactate racemase in Megasphaera elsdenii grown on glucose or lactate; Hino T et al.; Activity of D-lactate dehydrogenase (D-LDH) was shown not only in cell extracts from Megasphaera elsdenii grown on DL-lactate, but also in cell extracts from glucose-grown cells, although glucose-grown cells contained approximately half as much D-LDH as DL-lactate-grown cells . This indicates that the D-LDH of M . elsdenii is a constitutive enzyme . However, lactate racemase (LR) activity was present in DL-lactate-grown cells, but was not detected in glucose-grown cells, suggesting that LR is induced by lactate . Acetate, propionate, and butyrate were produced similarly from both D- and L-lactate, indicating that LR can be induced by both D- and L-lactate . These results suggest that the primary reason for the inability of M . elsdenii to produce propionate from glucose is that cells fermenting glucose do not synthesize LR, which is induced by lactate.

J Dairy Sci, 1993 Jan, 76(1), 245 - 54
Carbohydrate and Aspergillus oryzae effects on intake, digestion, and milk production by dairy cows; Sievert SJ et al.; Six multiparous, ruminally cannulated Holstein cows (46 DIM, 584 kg of BW) and 6 primiparous Holstein cows (35 DIM, 506 kg of BW) were used in two 6 x 6 Latin squares with 21-d periods to examine the effects of level of non-fiber carbohydrate, source of fibrous carbohydrate, and Aspergillus oryzae fermentation extract on intake, digestion, and milk production . Treatments were 42 and 36% non-fiber carbohydrate; shelled corn and soybean meal were replaced partially by beet pulp and dried brewers grains or soy hulls and dried brewers grains in 36% non-fiber carbohydrate diets . These three diets then were supplemented with 0 or 3 g/d of A . oryzae . Milk production and composition and DMI were not significantly affected by level or source of carbohydrate, although intake of NDF was significantly higher for 36% non-fiber carbohydrate diets . Total tract apparent digestibilities of ADF and NDF were higher for 36% non-fiber carbohydrate diets . Supplementation with A . oryzae did not significantly affect DMI, milk production, or total tract apparent digestibilities; however, milk fat content was decreased . Partial replacement of corn with fibrous carbohydrate sources, beet pulp and soy hulls, did not adversely affect intake or milk production in early lactation cows fed alfalfa silage-based diets.

J Antibiot (Tokyo), 1993 Jan, 46(1), 11 - 7
Tetronothiodin, a novel cholecystokinin type-B receptor antagonist produced by Streptomyces sp . NR0489 . II . Isolation, characterization and biological activities; Ohtsuka T et al.; A novel cholecystokinin type-B receptor antagonist named tetronothiodin has been isolated by column chromatography and preparative HPLC from the fermentation broth of Streptomyces sp . NR0489 . Tetronothiodin inhibited the binding of CCK8 (C-terminal octapeptide of cholecystokinin) to rat cerebral cortex membranes (CCK type-B receptors) with an IC50 of 3.6 nM, whereas it did not inhibit CCK8 binding to rat pancreatic membranes (CCK type-A receptors) . It also inhibited CCK8 induced Ca2+ mobilization in GH3 cells, a rat anterior pituitary cell line, but was without effect on the basal cytosolic Ca2+ concentration . This finding indicated tetronothiodin was an antagonist of CCK type-B receptors.

J Antibiot (Tokyo), 1993 Jan, 46(1), 1 - 10
Tetronothiodin, a novel cholecystokinin type-B receptor antagonist produced by Streptomyces sp . NR0489 . I . Taxonomy, yield improvement and fermentation; Watanabe J et al.; Streptomyces sp . NR0489 produces tetronothiodin, a novel brain-type cholecystokinin receptor antagonist . This species was differentiated from its related species S . gelaticus, S . griseolus and S . hydrogenans on the basis of their cultural characteristics, such as the utilization of carbohydrates and the presence or absence of various enzymatic activities . We applied the DNA-DNA hybridization method using photobiotin, which proved the genetic difference between the four species mentioned above . The yield improvement effort including single colony isolation, mutation, and protoplast regeneration together with medium optimization resulted in more than an 81-fold increase of the productivity of tetronothiodin as compared to that of the wild type strain.

Cytometry, 1993, 14(1), 70 - 3
Rhodamine 123 fluorescence of immortal hybridoma cell lines as a function of glucose concentration; Borth N et al.; The fluorescence of rhodamine 123 stained cells has been described to specifically reflect the activity of mitochondria . Changes in the intensity of fluorescence observed in stimulated lymphocytes were attributed to an increased glycolytic activity of cells due to increased growth rates . Previously reported changes in mitochondrial activity observed in batch cultures were likewise attributed to changed growth rates . In this study we report that the Rh123 fluorescence of hybridoma cell lines in batch culture more closely correlates to the glucose concentration in the culture supernatant than to growth rates . When cells are transferred into glutamine free medium with defined glucose concentrations ranging from 0 to 3,000 mg/L the mean Rh123 fluorescence adapts to the respective glucose concentration within 6 hours and gives a linear correlation . This can be explained by the previously described dependence of specific glucose consumption rates on glucose availability in the medium . The importance of controlling glucose availability, especially in large scale fermentations, is discussed.

J Clin Microbiol, 1993 Jan, 31(1), 160 - 2
Growth of Helicobacter pylori in media containing cyclodextrins; Olivieri R et al.; We show that solid and liquid media, supplemented only with cyclodextrins and free of blood and its derivatives, support the growth of Helicobacter pylori . These media can be used for primary isolation of the bacteria from biopsy samples, routine laboratory growth, and large-scale industrial fermentation.

Microbios, 1993, 75(303), 95 - 106
Influence of fermentation conditions on specific activity of the enzymes alcohol and aldehyde dehydrogenase from yeasts; Mauricio JC et al.; The effects of anaerobic, semi-aerobic and short aeration fermentation conditions and the addition of ergosterol and oleic acid to musts on the specific activity of alcohol and aldehyde dehydrogenase (ADH and ALDH) from two yeast species, Saccharomyces cerevisiae and Torulaspora delbrueckii, were studied . ADH I biosynthesis only occurred during the first few hours of fermentation . ADH II from S . cerevisiae and ALDH-NADP+ from the two yeast species behaved as constitutive enzymes under all fermentation conditions . ADH II from T . delbrueckii was only synthesized in small amounts, and its activity was always lower than in S . cerevisiae, where it was responsible for the termination of alcoholic fermentation during the steady growth phase.

Arch Tierernahr, 1993, 43(4), 345 - 61
{Comparative studies of the parameters of rumen fermentation and the digestibility of feed rations in cattle and sheep . 1 . Parameters of rumen fermentation}; Jentsch W et al.; The results from 283 studies of rumen liquid, taken by means of oesophagus probe, from different species of cattle (ox, cow, male and female young cattle) and sheep (adult wether) are compared . In the rumen liquid the parts of volatile fatty acids (VFA), total VFA content, pH value and the content of NH3 and urea were analysed . In the cattle's rumen liquid the part of acetic acid is on average 2 Mol-% and the content of total VFA up to 28 mmol/l (middle of the cow--sheep comparisons) higher than in that of wether . The contents of NH3 and urea are lower in cattle than in wether . Relations between the amount of difference of characteristic rumen fluid numbers of cattle and sheep and the crude fibre content of the rations, the live weight of the young cattle and the nutrition level are considered.

Arch Tierernahr, 1993, 43(2), 95 - 116
Digestion of carbohydrates in the pig; Drochner W; A review of carbohydrate digestion in the pig is given . The cascade of digestion in the mouth, stomach, small and large intestine is described . Principles of enzymatic and fermentative digestion according to new results with fistulated animals are discussed . The efficacy and quality of fermentation in the large intestine depending on level and quality of carbohydrates in the diet are demonstrated . Some aspects of energetical efficacy of hindgut digestion are discussed . Dietetic effects of carbohydrates are described.

Arch Tierernahr, 1993, 43(2), 157 - 67
Influence of the ratio between wheat straw and ground barley, ground corn or dried sugar beet pulp on in sacco dry matter degradation of ryegrass and wheat straw, rumen fermentation and apparent digestibility in sheep; Flachowsky G et al.; Castrated male sheep were fed with 5 different rations varying in the straw to concentrate ratio between 100: 0, 75: 25, 50: 50, 25: 75 and 0: 100 . Ground barley, ground corn and dried sugar beet pulp were used as concentrate sources . Chopped winter wheat straw was fed as roughage source . All rations were supplemented with a protein-mineral-vitamin-premix . In sacco dry matter degradability of artificially dried ryegrass, untreated and ammonia treated wheat straw was measured within three rumen fistulated sheep . Nylon bags were incubated for 48 h in the rumen of sheep . Volatile fatty acids of rumen fluid were determined by gas chromatography . Samples were taken via rumen fistula 3 h after morning feeding . Apparent digestibility of organic matter and fibre fractions of total rations were determined within five sheep . Increased concentrate portion decreased in sacco dry matter degradability of incubated roughages . Decrease of dry matter degradability was much higher for ammonia treated (from 55.0 to 22.5%) and untreated straw (from 50.9 to 22.7%) than for ryegrass (from 75.6 to 69.2%), when concentrate increased from 0 to 100% of ration . The highest concentrate portions did not show any increase of degradability of ammonia treated straw . Specific concentrate effects were observed when 75 and 100% concentrate were fed (unphysiological level) . Ground barley as concentrate source decreased rumen pH to a larger extent (down to 5.18) than corn and sugar beet pulp (down to 5.60 and 5.57) . Sheep suffered from rumen acidosis in some cases . Higher concentrate levels increased concentration of total volatile fatty acids of rumen liquid and molar concentration of propionate and butyrate, but decreased acetate . Various concentrate sources showed different influences on parameters of rumen fermentation . Apparent digestibility of organic matter of total rations increased from 52.7 to 86.1% if concentrate portions enhanced from 0 to 100% . High portions of ground barley decreased cellulolytic activity and fibre digestion . On the other hand high levels of sugar beet pulp increased digestibility of crude fibre and neutral detergent fibre.

Arch Tierernahr, 1993, 43(2), 147 - 56
Influence of Rhaponticum carthamoides Wild on the growth of ruminal bacteria in vitro and on fermentation in an artificial rumen (Rusitec); Selepcova L et al.; The fermentation of a basal diet composed of hay and barley (80:20%) was compared with fermentation of three rations in which 5 and 10% of hay and 10% of basal diet were replaced with the above-ground part of Rhaponticum carthamoides Wild in an artificial rumen (Rusitec) . Results of 14 days experiments indicated that the digestibility of dry matter, organic matter, detergent fibre, production of CO2 and methane, NH3-N in effluent and total and individual VFA (mmol/day) were not affected in the process of fermentation of experimental diets in comparison with the basal diet . Addition of Rhaponticum carthamoides did not modify the production, utilization and recovery of metabolic hydrogen, glucose utilization, ATP production, YATP and effectiveness of microbial biomass synthesis expressed in g of microbial N/kg of organic fermented biomass . Water extracts of Rhaponticum carthamoides had no influence on growth parameters of a mixed culture of rumen bacteria . Overall results of this experiment indicated that the above-ground part of Rhaponticum carthomoides fully replaced the 5 and 10% portions of hay or 10% portion of the whole diet.

Br J Nutr, 1993 Jan, 69(1), 233 - 41
Cholecalciferol supplementation alters gut function and improves digestibility in an underground inhabitant, the naked mole rat (Heterocephalus glaber), when fed on a carrot diet; Yahav S et al.; Naked mole rats (Heterocephalus glaber) lead a strictly subterranean existence and appear to be naturally deficient in cholecalciferol (D3) . Oral supplementation with D3 (Ds) led to a 1.8-fold increase in food intake and the associated enlargement (1.4-fold) of the caecum . The effect of Ds, and the concomitant increase in food intake, on caecal fermentation efficiency when animals were fed on a carrot-based diet was determined by measuring the rate of both gas production and short-chain fatty acid (SCFA) production . Microbial-controlled fermentation processes in the caecum were enhanced with Ds when compared with animals not receiving a D3 supplement (Dn) . Both the rates of gas production (Dn 10.76 (SE 0.77), Ds 15.20 (SE 1.77) ml/g dry matter (DM) per h) and SCFA production (Dn 463.0 (SE 33.7), Ds 684.3 (SE 74.8) mumol/g DM per h) increased more than 1.4-fold per g DM caecal substrate . These factors contributed to the higher digestibility of the food in Ds animals . The larger quantity of energy available to D3-replete naked mole rats was not used in anabolic processes, for these animals maintained mass . These findings suggest that metabolic rate in D3-replete animals was elevated . Thus, despite improved gut function, D3-replete animals may be disadvantaged by their higher energy and food requirements in their natural milieu.

Br J Nutr, 1993 Jan, 69(1), 177 - 88
Uniformly 14C-labelled plant cell walls: production, analysis and behaviour in rat gastrointestinal tract; Gray DF et al.; Uniformly 14C-labelled primary cell walls (14C-PCW) were purified from suspension-cultured cells of spinach (Spinacia oleracea L.) grown in a medium containing D-{U-14C}glucose . The approximate polymer composition of the 14C-PCW preparation (% total 14C) was homogalacturonan 30, rhamnogalacturonan 23, xyloglucan 10, other hemicelluloses 3, cellulose 21, lignin 0, 14C-labelled protein < 3 and {14C}starch < 2 . The degree of methyl esterification of the pectic polysaccharides was about 25% . The 14C-PCW contained about 4% O-acetyl and 3% non-volatile ester-linked residues . When tracer levels of these 14C-PCW were fed to rats, only about 18% of the 14C appeared in the faeces; negligible levels of 14C (0.07%) remained in the gut contents 4 d after feeding . Some 14C was present in the carcass . The results show that U-14C-labelled primary cell walls can be purified and radiochemically analysed by the methods developed here, and that primary cell walls are extensively fermented by the gut microflora of the rat.

J Anim Sci, 1993 Jan, 71(1), 18 - 25
Influence of sodium bicarbonate and monensin on utilization of a fat-supplemented, high-energy growing-finishing diet by feedlot steers; Zinn RA et al.; Two feedlot growth performance trials and a metabolism trial were conducted to evaluate the relationship between monensin (MON) and sodium bicarbonate (BICARB) supplementation on utilization of a high-energy diet by finishing steers . Two levels of MON (0 and 33 mg/kg of diet) and two levels of BICARB (0 and .75% DM) were compared in a 2 x 2 factorial arrangement of treatments . The basal diet contained 75% steam-flaked corn, 4% yellow grease, and 12% forage (DM basis) . There were no interactions between supplemental BICARB and MON on feedlot growth performance or characteristics of ruminal and total tract digestion . With either crossbred or Holstein steers there were no treatment effects (P > .10) on ADG, DM intake, feed efficiency, or NE value of the diet . The BICARB did not influence (P > .10) ruminal or total tract digestion of OM, ADF, starch, and N, ruminal pH, or ruminal VFA molar proportions . Monensin decreased (6.6%, P < .10) ruminal OM digestion . However, differences in ruminal digestion were compensated for by increased (3.2%, P < .05) postruminal OM digestion . Effects of MON on total tract digestion of OM, ADF, N, starch and GE were small (P > .10) . Monensin decreased ruminal molar proportions of acetate (5.3%, P > .10) and butyrate (29.4%, P < .05) and increased molar proportions of propionate (16.3%, P < .10) . Coupled with reduced ruminal OM fermentation, the increase in molar proportions of propionate caused a decrease in ruminal methane energy loss and increased diet ME (2.7%, P < .05).(ABSTRACT TRUNCATED AT 250 WORDS)

Yeast, 1993 Jan, 9(1), 95 - 7
QCR9, the nuclear gene encoding a small subunit of the mitochondrial cytochrome bc1 complex, maps to the right arm of chromosome VII in Saccharomyces cerevisiae; Phillips JD et al.; We present here mapping data for QCR9, a nuclear gene encoding a subunit of the ubiquinol-cytochrome c oxidoreductase complex . Deletion of QCR9 results in the inability of cells to grow on grow on-fermentable carbon sources at 37 degrees C . Thus, qcr9 mutants can be scored by growing cells on YPE/G at 37 degrees C, or followed by the URA3 marker, which was inserted when making the qcr9 deletion strain, JDP1 . The location of QCR9 on the right arm of chromosome VII with respect to the previously mapped genes ADE3, SER2 and PET54 is given.

Nahrung, 1993, 37(4), 305 - 20
{The energetic utilization of L-fructose in rats}; Klein M et al.; The energetic utilization of L-fructose (LF) and D-fructose (DF) was investigated by means of indirect calorimetry in a difference trial on 9 male Wistar rats in the live weight range of 250 to 300 g . The daily rations in the two comparable periods with added fructose consisted of 10 g basal diet plus 2.7 g LF or 2.5 g DF . The digestibility and metabolizability of energy of the LF-ration were decreased by about 4 and 6%, resp., in comparison to the DF-ration . The efficiency of total utilization of energy (energy deposition/gross energy) amounted to (7 +/- 3)% (mean +/- SD) for the LF-ration and (10 +/- 3)% for the DF-ration . The lower digestibility of energy of the LF-ration was mainly due to a depression of apparent digestibility of crude protein, crude fat and crude fibre--obviously caused by increased microbial fermentation . With correction of the depression of digestibility the following values of energetic utilization resulted from the difference evaluation for LF and DF, resp.: digestibility (90 +/- 8)% and (100 +/- 6)%, metabolizability (85 +/- 8)% and (102 +/- 5)%, utilization of gross energy for energy deposition (69 +/- 11)% and (86 +/- 11)% and utilization of metabolizable energy (81 +/- 7)% and (84 +/- 11)%, resp.

Folia Microbiol (Praha), 1993, 38(2), 141 - 6
Continuous cultivation of the yeast Saccharomyces cerevisiae at different dilution rates and glucose concentrations in nutrient media; Pejin D et al.; The influence of glucose concentration in nutrient media on the specific growth rate and biomass yield in the course of continuous fermentation of Saccharomyces cerevisiae was investigated . An increase of glucose content in media decreased the specific growth rate and the biomass yield . Glucose concentration had significant effects on protein and phosphate contents of cells . However, an increased glucose concentration increased the fermentative power of S . cerevisiae (SJA-method) . An increase of the dilution rate decreased the cell concentration in the fermentor . Specific growth rate approach the values of the dilution rate . The best agreement has been obtained at a dilution rate of 0.20/h . This dilution rate proved to be most convenient for the investigated microorganism and cultivation conditions (media composition, pH, aeration intensity and temperature) . Biomass yield proved to be decreased by an increase of the dilution rate.

Reprod Nutr Dev, 1993, 33(2), 89 - 98
{Effects of treatments (heat and fermentation by Rhizopus oligosporus sp-T3) of sweet white lupin seeds on certain factors of its nutritional use}; Chango A et al.; For improving the nutritional value and functional properties of sweet white lupin (SWL), a solid fermentation process using Rhizopus oligosporus was developed for the preparation of lupin products . A comparison of the effects of soaking + thermal treatment and fermentation was made from 3 lupin products: non-treated lupin seeds (SWLnt), heated lupin seeds (steamed at 100 degrees C for 30 min) (SWLh), and fermented lupin products (SWLf) from SWLh on chemical characteristics and protein efficiency ratio (PER) in rats . The major effect of soaking and thermal treatment is a loss of protein solubility and available lysine (from 3.02 +/- 0.18 g/16 g N to 2.3 +/- 0.25) . Fermentation leads to a modification, of amino acid composition and to an increase in available lysine compared to heating (2.90 +/- 0.12 g/16 g N) . The nutritional quality of SWLnt is low (PER = 0.83 +/- 0.09), thermal treatment decreases it (0.58 +/- 0.18) and fermentation compensates heating effect (0.74 +/- 0.25) . It is suggested that the modifications of nutritional quality depends on the availability of lysine rather than on the variations of the levels of other amino acids.

J Basic Microbiol, 1993, 33(3), 161 - 7
Fermenter cultivation of intestinal spirochaetes; Borrmann E et al.; We cultivated 6 strains of intestinal spirochaetes in a laboratory fermenter under constant conditions (medium, physical-chemical parameters) in a permanent gas flow . It has been possible to demonstrate that the application of the fermenter technique for the cultivation of spirochaetes is a suitable method which can be easily standardized.

Appl Biochem Biotechnol, 1993 Spring, 39-40, 667 - 85
Production of ethanol from pulp mill hardwood and softwood spent sulfite liquors by genetically engineered E . coli; Lawford HG et al.; Although lignocellulosic biomass and wastes are targeted as an attractive alternative fermentation feedstock for the production of fuel ethanol, cellulosic ethanol is not yet an industrial reality because of problems in bioconversion technologies relating both to depolymerization and fermentation . In the production of wood pulp by the sulfite process, about 50% of the wood (hemicellulose and lignin) is dissolved to produce cellulose pulp, and the pulp mill effluent ("spent sulfite liquor" SSL) represents the only lignocellulosic hydrolysate available today in large quantities (about 90 billion liters annually worldwide) . Although softwoods have been the traditional feedstock for pulping operations, hardwood pulping is becoming more popular, and the pentose sugars in hardwood SSL (principally xylose) are not fermented by the yeasts currently being used in the production of ethanol from softwood SSL . This study assessed the fermentation performance characteristics of a patented (US Pat . 5,000,000), recombinant Escherichia coli B (ATCC 11303 pLOI297) in anaerobic batch fermentations of both nutrient-supplemented soft and hardwood SSL (30-35 g/L total reducing sugars) . The pH was controlled at 7.0 to maximize tolerance to acetic acid . In contrast to the high-performance characteristics exhibited in synthetic media, formulated to mimic the composition of softwood and hardwood SSL (yield approaching theoretical maximum), performance in SSL media was variable with conversion efficiencies in the range of 67-84% for hardwood SSL and 53-76% for softwood SSL . Overlimiting treatment of HSSL, using Ca(OH)2, improved overall volumetric productivity two- to sevenfold to a max of 0.42 g/L/h at an initial cell loading of 0.5 g dry wt/L . A conversion efficiency of 92% (6.1 g/L ethanol) was achieved using diluted Ca(OH)2-treated hardwood SSL . The variable behavior of this particular genetic construct is viewed as a major detractant regarding its candidacy as a biocatalyst for SSL fermentations.

Appl Biochem Biotechnol, 1993 Spring, 39-40, 301 - 22
Effects of pH and acetic acid on glucose and xylose metabolism by a genetically engineered ethanologenic Escherichia coli; Lawford HG et al.; Efficient utilization of the pentosan fraction of hemicellulose from lignocellulosic feedstocks offers an opportunity to increase the yield and to reduce the cost of producing fuel ethanol . The patented, genetically engineered, ethanologen Escherichia coli B (pLOI297) exhibits high-performance characteristics with respect to both yield and productivity in xylose-rich lab media . In addition to producing monomer sugar residues, thermochemical processing of biomass is known to produce substances that are inhibitory to both yeast and bacteria . During prehydrolysis, acetic acid is formed as a consequence of the deacetylation of the acetylated pentosan . Our investigations have shown that the acetic acid content of hemicellulose hydrolysates from a variety of biomass/waste materials was in the range 2-10 g/L (33-166 mM) . Increasing the reducing sugar concentration by evaporation did not alter the acetic acid concentration . Acetic acid toxicity is pH dependent . By virtue of its ability to traverse the cell membrane freely, the undissociated (protonated) form of acetic acid (HAc) acts as a membrane protonophore and causes its inhibitory effect by bringing about the acidification of the cytoplasm . With recombinant E . coli B, the pH range for optimal growth with glucose and xylose was 6.4-6.8 . With glucose, the pH optimum for ethanol yield and volumetric productivity was 6.5, and for xylose it was 6.0 and 6.5, respectively . However, the decrease in growth and fermentation efficiency at pH 7 is not significant . At pH 7, only 0.56% of acetic acid is undissociated, and at 10 g/L, neither the ethanol yield nor the maximum volumetric productivity, with glucose or xylose, is significantly decreased . The "uncoupling" effect of HAc is more pronounced with xylose and the potency of HAc is potentiated in a minimal salts medium . Controlling the pH at 7 provided an effective means of circumventing acetic acid toxicity without significant loss in fermentation performance of the recombinant biocatalyst.

Appl Biochem Biotechnol, 1993 Spring, 39-40, 177 - 89
Production of cellulolytic and xylanolytic enzymes during growth of anaerobic fungi from ruminant and nonruminant herbivores on different substrates; Teunissen MJ et al.; Three anaerobic fungi, two Neocallimastix strains isolated from a ruminant (sheep) and one Piromyces strain isolated from a nonruminant (black rhinoceros), were tested for their ability to ferment a range of substrates . Bagasse, filter paper cellulose, fructose, and wheat straw were good inducers of celluloytic and xylanolytic enzymes . These enzymes were produced constitutively by all three strains, although enzyme activities were generally lower, especially for both Neocallimastix strains, after growth on glucose and other soluble sugars . The isoenzyme patterns of extracellular enzyme preparations of Neocallimastix strains were influenced by the growth substrate.

Microb Pathog, 1993 Jan, 14(1), 57 - 66
One step high yield affinity purification of shiga-like toxin II variants and quantitation using enzyme linked immunosorbent assays; Acheson DW et al.; We have previously purified both shiga-like toxin (SLT) I and II using the toxins' affinity to P1 glycoprotein (P1gp) from hydatid cyst material (HCM) . Binding of these toxins is based on their affinity for terminal Gal alpha 1-->4Gal disaccharide residues present in HCM . Although the binding specificity of SLT-II variants (v) differs from that of STL-II they are reported to recognize Gb3 and should bind to P1gp . Therefore we examined the usefulness of HCM to purify SLT-IIv of porcine (p) and human (h) origin . Toxins were purified from fermenter culture supernatants of Escherichia coli HB101 (pDLW5) (SLT-IIvp), and E . coli DH5 alpha (pJES210) (SLT-IIvh) utilizing HCM . SLT-IIvh and SLT-IIvp consisted of A and B subunits, as determined by SDS-PAGE . We obtained 0.16 mg SLT-IIvp and 0.12 mg SLT-IIvh/I of culture (yields > 65%) . Various capture systems to detect shiga toxin, SLT-II, SLT-IIvp and SLT-IIvh by ELISA were examined . All toxins bound to HCM, and all except SLT-IIvp bound to the monoclonal antibody 4D1 . Only SLT-IIvp bound to the glycolipid Gb4, and only shiga toxin bound significantly to Gb3 . Similarities in the level of Gb4 expression in HeLa 229 (ATCC) and Vero cells may explain the lack of differential cytotoxicity between SLT-IIvp and SLT-IIvh on these cell lines.

Acta Microbiol Bulg, 1993, 30, 51 - 5
Kinetics of the gluconic acid biosynthesis by strain Aspergillus niger 13-73; Tsekova K et al.; The kinetics of gluconic acid biosynthesis of the strain Aspergillus niger 13-73 by submerged cultivation in a medium containing 26% glucose was investigated . The maximum amount of the product was obtained at minimum biomass growth . The yield of the product compared to the theoretical one was 95% and the fermentation period was 42 hours . The results regarding the limitation theory are discussed.

Antonie Van Leeuwenhoek, 1993, 63(3-4), 375 - 81
Kinetics of microbial product formation and its consequences for the optimization of fermentation processes; de Hollander JA; Different types of product formation kinetics are discussed with respect to their significance for fermentation process economics . Microbial products belonging to various classes are formed in a growth-coupled manner . It is often found that the specific rate of product formation increases with the specific growth rate, approaching a maximum at higher growth rates . It is illustrated that for such types of relationship between the product formation rate and the growth rate process conditions are optimal when the specific rate of product formation is about half-maximal.

Antonie Van Leeuwenhoek, 1993, 63(3-4), 353 - 73
Dynamics of microbial growth and metabolic activity and their control by aeration; Kalina V; The optimization of fermentation processes depends to a large extent on the modelling of microbial activity under complex environmental conditions where aeration is an important limiting and control factor . Simple relationships are used to establish the sensitivity of cultures to oxygen stress . Specific limitation coefficients which can be determined in laboratory reactors allow a projection to industrial operation and the definition of appropriate aeration and agitation profiles . Optimum control can be assured on the basis of directly measurable process parameters . This is shown for the case of ethanol production using S . cerevisiae at high cell dry weight concentrations.

Antonie Van Leeuwenhoek, 1993, 63(3-4), 343 - 52
Kinetics of growth and sugar consumption in yeasts; van Dijken JP et al.; An overview is presented of the steady- and transient state kinetics of growth and formation of metabolic byproducts in yeasts . Saccharomyces cerevisiae is strongly inclined to perform alcoholic fermentation . Even under fully aerobic conditions, ethanol is produced by this yeast when sugars are present in excess . This so-called 'Crabtree effect' probably results from a multiplicity of factors, including the mode of sugar transport and the regulation of enzyme activities involved in respiration and alcoholic fermentation . The Crabtree effect in S . cerevisiae is not caused by an intrinsic inability to adjust its respiratory activity to high glycolytic fluxes . Under certain cultivation conditions, for example during growth in the presence of weak organic acids, very high respiration rates can be achieved by this yeast . S . cerevisiae is an exceptional yeast since, in contrast to most other species that are able to perform alcoholic fermentation, it can grow under strictly anaerobic conditions . 'Non-Saccharomyces' yeasts require a growth-limiting supply of oxygen (i.e . oxygen-limited growth conditions) to trigger alcoholic fermentation . However, complete absence of oxygen results in cessation of growth and therefore, ultimately, of alcoholic fermentation . Since it is very difficult to reproducibly achieve the right oxygen dosage in large-scale fermentations, non-Saccharomyces yeasts are therefore not suitable for large-scale alcoholic fermentation of sugar-containing waste streams . In these yeasts, alcoholic fermentation is also dependent on the type of sugar . For example, the facultatively fermentative yeast Candida utilis does not ferment maltose, not even under oxygen-limited growth conditions, although this disaccharide supports rapid oxidative growth.

Crit Rev Microbiol, 1993, 19(3), 137 - 88
Tempeh: a mold-modified indigenous fermented food made from soybeans and/or cereal grains; Hachmeister KA et al.; A variety of indigenous fermented foods exist today; however, tempeh has been one of the most widely accepted and researched mold-modified fermented products . Tempeh is a traditional fermented food made from soaked and cooked soybeans inoculated with a mold, usually of the genus Rhizopus . After fermentation has occurred, the soybeans are bound together into a compact cake by dense cottony mycelium . An important function of the mold in the fermentation process is the synthesis of enzymes, which hydrolyze soybean constituents and contribute to the development of a desirable texture, flavor, and aroma of the product . Enzymatic hydrolysis also may decrease or eliminate antinutritional constituents; consequently, the nutritional quality of the fermented product may be improved . Current technology and new scientific advancements have enabled researchers to examine specific strains of Rhizopus and new substrates such as cereal grains . Because Kansas produces numerous cereal grains, production of a fermented tempeh-like product using wheat, sorghum (milo), oats, rye, barley, corn, and triticale is a definite possibility for generating a Kansas Value-Added Product . In this study, several different tempeh-like products were produced using various cereal grains inoculated with Rhizopus oligosporus NRRL 2549 or R . oligosporus NRRL 2710 . Grains used included hard red winter wheat, triticale, yellow sorghum (milo), and red sorghum (milo) . The grain source as well as the strain of R . oligosporus used influenced the product's appearance, flavor, and patty integrity . Results showed that R . oligosporus NRRL 2549 produced more mycelium at a more rapid rate than did the R . oligosporus NRRL 2710 strain . The combination of red sorghum and R . oligosporus NRRL 2549 yielded a product with good patty texture, aroma, and appearance . Furthermore, the red sorghum fermented product was well suited for slicing . On the other hand, yellow sorghum inoculated with either R . oligosporus NRRL 2549 or R . oligosporus NRRL 2710 failed to produce an organoleptically suitable product . Triticale also was found to be an unacceptable substrate for the production of a tempeh-like product . Although the fermented wheat product had a desirable aroma and flavor, it lacked patty integrity and crumbled when sliced . Further research is needed to evaluate the economic significance and industrial applications of these tempeh-like products.

Microbios, 1993, 76(306), 59 - 66
A simple and efficient continuous culture system for Helicobacter pylori; Ho B et al.; Helicobacter pylori has been successfully maintained in a continuous culture system . The culture was grown in 0.6 litre of brain heart infusion broth with supplements in a 1 litre fermenter with a flow rate of 25 ml/h, an 80% dilution rate and a specific growth rate of 0.06/h . Unlike the typical growth curve which occurred in batch culture, the growth pattern in continuous culture showed a short lag phase following which growth was maintained in exponential phase with > or = 10-fold increase in viability and the pH was stabilised at 6.95 +/- 0.05 . The urease activity remained constant in relation to viability while the urea was completely hydrolysed . The system provides cells with growth characteristics similar to the fresh isolate which are highly adaptable to the in vitro environment . This study shows that continuous culture is a simple and efficient growth system for the cultivation of a 'synchronous' spiral form of H . pylori.

Folia Microbiol (Praha), 1993, 38(5), 383 - 6
Monensin has no effect on growth and metabolism of Megasphaera elsdenii; Marounek M et al.; A rumen strain of Megasphaera elsdenii was grown on glucose and lactate in monensin-free and monensin-supplemented medium (10 mg/L) . Monensin had no effect on growth rate, growth yields, metabolic pattern and composition of cells . Growth yields of dry matter and protein were higher in cultures supplied with glucose than in cultures supplied with lactate . The bacterium compensated the lower gain of energy from fermentation of lactate by rapid utilization of this substrate . Cells grown on glucose contained more saccharide and less protein than lactate-grown cells.

Arch Microbiol, 1993, 160(5), 388 - 96
Characterization of hydrogenosomes and their role in glucose metabolism of Neocallimastix sp . L2; Marvin-Sikkema FD et al.; In the anaerobic fungus Neocallimastix sp . L2 fermentation of glucose proceeds via the Embden-Meyerhof-Parnas pathway . Enzyme activities leading to the formation of succinate, lactate, ethanol, and formate are associated with the cytoplasmic fraction . The enzymes 'malic enzyme,' NAD(P)H:ferredoxin oxidoreductase, pyruvate:ferredoxin oxidoreductase, hydrogenase, acetate:succinate CoA transferase and succinate thiokinase leading to the formation of H2,CO2, acetate, and ATP are localized in microbodies . Thus, these organelles are identified as hydrogenosomes . In addition, the microbodies contain the O2-scavenging enzymes NADH- and NADPH oxidase, while NAD(P)H peroxidase, catalase, or superoxide dismutase could not be detected . In cell-free extracts from zoospores of Neocallimastix sp . L2 the specific activities of hydrogenosomal enzymes as well as the quantities of these proteins are 2- to 6-fold higher than in mycelium extracts . These findings suggest that hydrogenosomes perform an important role--especially in zoospores--as H2-evolving, ATP-generating and O2-scavenging organelles.

Annu Rev Microbiol, 1993, 47, 627 - 58
Enzymes and proteins from organisms that grow near and above 100 degrees C; Adams MW; Microorganisms that can grow at and above 100 degrees C were discovered a decade ago, and about 20 different genera are now known . These so-called hyperthermophiles are the most ancient of all extant life; all but two genera are classified as Archaea . All have been isolated from geothermal heated environments including deep-sea hydrothermal vents . This group includes some methanogenic and sulfate-reducing species, but the majority are strictly anaerobic heterotrophs that utilize complex peptide mixtures as sources of energy, carbon, and nitrogen . Only a few species are saccharolytic . Most of the hyperthermophiles absolutely depend on the reduction of elemental sulfur (S0) to H2S for significant growth, a property that severely limits their large-scale culture in conventional fermentation systems . Consequently, most physiological and metabolic studies have focused on those that can also grow in the absence of S0, including species of the Archaea, Pyrococcus and Thermococcus, and the bacterium Thermotoga . The fermentative pathways for the metabolism of both peptides and carbohydrates in the Archaea appear to depend upon enzymes that contain tungsten, an element seldom used in biological systems . The mechanisms of S0 reduction and energy conservation remain unclear . Enzymes purified from the S0-reducing hyperthermophiles include proteases, amylolytic-type enzymes, hydrogenases, redox proteins, various ferredoxin-linked oxidoreductases, dehydrogenases, and DNA polymerases, some of which are active up to 140 degrees C . However, complete amino acid sequences are known for only a handful of these proteins, and the three-dimensional structure of only one hyperthermophilic protein has been determined . Potential mechanisms by which proteins and various biological cofactors and organic intermediates are stabilized at extreme temperatures are only now beginning to emerge.

Biosens Bioelectron, 1993, 8(6), 339 - 45
Studying the bienzyme reaction with amperometric detection for measuring maltose; Varadi M et al.; If a fermentation process is followed by a change in the concentration of maltose, information on the level of the maltose is important . A new type of sensor was developed for measuring the content of maltose in fermentation broth . The base of the sensor is a thin-layer reactor, in which a protein membrane was chosen for the immobilization of enzymes . To measure maltose, we investigated the influence of enzymes such as alpha-glucosidase (EC 3.2.1.20) and amyloglucosidase (EC 3.2.1.3) on the effectiveness of conversion to glucose . Because amyloglucosidase proved to be more effective, a mixture of amyloglucosidase and glucose oxidase was applied for the determination of maltose . To develop the best measuring technique, the consequences of changes in different parameters, such as the optimal ratio of enzymes, role of pH value and that of the flow rate, were studied . An amperometric measuring cell with Pt-Ag/AgCl-Pt electrodes was used at +600 mV operating potential . The results indicate that the maltose content in different types of fermentation broth can be determined by the new measuring cell in the range of 0.2-4 mM maltose . The cell was successfully tested in the fermentation of brewer's yeast.

Arch Microbiol, 1993, 160(4), 288 - 94
Effects of dilution rate and pH on the ruminal cellulolytic bacterium Fibrobacter succinogenes S85 in cellulose-fed continuous culture; Weimer PJ; The ruminal cellulolytic bacterium Fibrobacter succinogenes S85 was grown in cellulose-fed continuous culture at 22 different combinations of dilution rate (D, 0.014-0.076 h-1) and extracellular pH (6.11-6.84) . Effects of pH and D on the fermentation were determined by subjecting data on cellulose consumption, cell yield, product yield (succinate, acetate, formate), and soluble sugar concentration to response surface analysis . The extent of cellulose conversion decreased with increasing D . First-order rate constants at rapid growth rates were estimated as 0.07-0.11 h-1, and decreased with decreasing pH . Apparent decreases in the rate constant with increasing D was not due to inadequate mixing or preferential utilization of the more amorphous regions of the cellulose . Significant quantities of soluble sugars (0.04-0.18 g/l, primarily glucose) were detected in all cultures, suggesting that glucose uptake was rather inefficient . Cell yields (0.11-0.24 g cells/g cellulose consumed) increased with increasing D . Pirt plots of the predicted yield data were used to determine that maintenance coefficient (0.04-0.06 g cellulose/g cells.h) and true growth yield (0.23-0.25 g cells/g cellulose consumed) varied slightly with pH . Yields of succinate, the major fermentation endproduct, were as high as 1.15 mol/mol anhydroglucose fermented, and were slightly affected by dilution rate but were not affected by pH . Comparison of the fermentation data with that of other ruminal cellulolytic bacteria indicates that F . succinogenes S85 is capable of rapid hydrolysis of crystalline cellulose and efficient growth, despite a lower mu max on microcrystalline cellulose.

Acta Vet Scand Suppl, 1993, 89, 119 - 24
Different forms of rumen dystonia in dairy cows; Sederevicius A et al.; Four naturally occurring main forms of rumen dystonia of alimentary origin were observed in cattle: acidotic conditions; microflora inactivity; acidosis, and alkalosis . The following disturbances in the metabolism of carbohydrates, protein and energy were observed: 1 . Acidotic conditions in rumen--ruminal pH, total and protein nitrogen decreased, whereas the total amount of VFA and the reduction activity of bacteria increased . 2 . Inactivity of rumen microflora--significant changes of pH of rumen fluid were not observed, but the total number and activity of infusoria decreased . Fermentation of glucose, digestibility of cellulose, and reduction activity of bacteria decreased, whereas the amount of non-protein nitrogen increased . 3 . Acidosis--ruminal pH, reduction activity of bacteria, and total number of VFA decreased . The percentage ratio between VFA changed--acetic acid concentration decreased, the concentration of valeric and caproic acids increased . The amount of total and non-protein nitrogen increased . 4 . Alkalosis--ruminal pH increased, reduction activity of bacteria, fermentation of glucose, and concentration of VFA decreased . The amount of total and non-protein nitrogen increased . This investigation of different forms of rumen dystonia of alimentary origin is believed to be useful for the development of more effective treating methods and measures.

J Basic Microbiol, 1993, 33(5), 311 - 21
Investigations of the oxygen supply in Ca-alginate beads and microcapsules loaded with Penicillium raistrickii using a microelectrode; Irrgang S et al.; The oxygen supply of free, Ca-alginate entrapped and microencapsulated mycelia of Penicillium raistrickii i 477 capable of 15 alpha-hydroxylation of 13-ethyl-gon-4-en-3,17-dione was investigated . Using an oxygen microelectrode distinct gradients of oxygen within the Ca-alginate beads as well as the microcapsules were detected . Slope and width of the gradients were investigated in dependence on the kind of immobilization, the culture age and the cell density on or in the carrier as well as the different forms of the oxygen supply in the medium . So it could be shown that large parts of immobilizates, approximately 96% of the diameter of both types, were oxygen-free . In comparison with free mycelia, the lower oxygen supply of the immobilized mycelia led to a metabolic shift to fermentative catabolism.

Int Arch Allergy Immunol, 1993, 102(3), 249 - 58
Characterization of recombinant bet vI, the major pollen allergen of Betula verrucosa (white birch), produced by fed-batch fermentation; Larsen JN et al.; The gene encoding the major allergen, Bet v I, from Betula verrucosa (white birch) pollen was cloned by application of the polymerase chain reaction with double-stranded cDNA as template and specific primers based on the published nucleotide sequence of the gene . The gene was inserted into plasmid pKK223-3 and expressed in Escherichia coli K-12 strain JM105 grown to high cell density in a fermenter using a fed-batch procedure . Ample material was provided for a thorough characterization of the epitope structure of recombinant Bet v I contained in an unpurified soluble lysate . The antibody-binding characteristics of recombinant Bet v I was compared with that of the natural allergen using polyclonal rabbit antibodies raised against Bet v I in crossed immunoelectrophoresis, tandem crossed immunoelectrophoresis, and Western blotting . IgE from a pool of 16 allergic patients' serum was applied in crossed radioimmunoelectrophoresis, Western blotting, and a quantitative luminescence inhibition immunoassay . Well-defined epitopes were assayed by the application of a panel of six murine monoclonal antibodies in a quantitative radio inhibition immunoassay . In all assays the activity of recombinant Bet v I was comparable to that of natural Bet v I, and it is concluded that the epitope structure of recombinant Bet v I closely resembles that of natural Bet v I . This result has important implications for the future use of recombinant tree pollen allergens as a model system for the study of allergenic B and T cell epitopes aiming at improvements in reagents used for the management of allergic disease.

Arch Tierernahr, 1993, 44(4), 369 - 82
{The effect of starch sources barley, maize and potatoes and their ration portions on the nutrient digestibility and energy utilization in ruminants . 4 . Nitrogen metabolism in the rumen}; Voigt J et al.; In 9 experimental periods on four adult bulls (LW 550 kg) fitted with re-entrant cannulae in the proximal duodenum isoenergetic rations were used on feeding level 1.7 with ground barley, ground maize or fresh potatoes as starch sources . The net energy parts of these concentrates in the ration amounted to 50, 25 and 10% . 50 to 80% of the ration DM consisted of dried grass and about 10% of sugar beet pulp . The dried grass supplied on an average 87, 79 and 62% of the feed crude protein . The intake of DM was 7.74 +/- 0.42 (mean +/- SD) kg/d . The energetic efficiency of microbial N synthesis in the rumen (g N/kg organic matter true fermented in the rumen, TFOM) was averaged 16.4 with a range of 10.6 to 21.4 . The microbial efficiency achieved a maximum when the ratio of nitrogen-free extract to crude fibre in the diet was 1.7 and 2.1 with barley, 1.8 with potatoes and 2.1 and 3.3 with corn as starch source . Changes in the microbial efficiency were positively correlated with the rate of passage of non-microbial organic matter from the rumen (g/d) and with the duodenal flow rate (kg digesta/kg DM intake) . The relation to the rate of carbohydrate fermentation in the rumen (in %) and to the amount of TFOM (g/d) was negative . The duodenal flow of microbial N and non-ammonia N (g/d) correlated negatively with the organic matter apparently fermented in the rumen (AFOM) and positively with the non AFOM . The amino acid (AA) profile of the duodenal protein was affected by the starch source . It was concluded that the metabolism of nitrogen in the forestomachs of cattle is affected by the source of starch and the ratio of forage to concentrate . There exists a relationship between both factors . The net synthesis of microbial protein in the rumen is not only the result of substrate fermentation . The passage of non-AFOM from the rumen significantly affects the energetic efficiency of microbial nitrogen synthesis and the duodenal supply of AA.

Arch Tierernahr, 1993, 44(3), 265 - 81
{Effect of the starch sources barley, corn and potatoes and their ration portions on nutrient digestibility and energy utilization in ruminants . 3 . Energy utilization in cattle}; Beyer M et al.; With investigations on the influence of different starch origins (barley, maize and raw potatoes) and different portions of the starch origins in the rations (50, 25 and 10% of the net energy fat, cattle (NEFr) content of the rations) on the energy utilization of rations a contribution was made to the development of the energetic feed evaluation within Rostock NEF-system . The experiments were carried out with fattened oxen using the methods of total metabolism technique and duodenal passage measurement by means of reentrant fistula . The nutrition levels amounted to 1.7 and 1.1 of energy maintenance requirement . The utilization of metabolizable energy for deposition of the 9 rations-including 3 variants of starch origins barley, maize and raw potatoes with parts in the rations of 50, 25 and 10%--was measured as 65, 61 and 59%, 61, 60 and 58% as well as 59, 61 and 55% . The energy maintenance requirement amounted to 526 kJ ME/kg LM 0.75.d . The gradations of energy utilization are caused by the connection between energy concentration and utilization of rations in ruminants . With comparable parts of the rations the different starch sources had no relevant influence on the energy utilization of the rations . Despite a wide range of starch plus water soluble carbohydrates (WSC) intake between 896 and 3426 g/animal.d no correlation between the kind of digestion (fermentative or enzymatic) of starch and WSC and the energy utilization of the rations was measurable, because the part of the ruminal digestion amounted to 86.0 and 97.2% . The result presented for the energy and nitrogen metabolism measurements are in good agreement with results of former experiments with 92 rations.

Arch Tierernahr, 1993, 44(1), 63 - 84
{Comparative studies of the parameters of rumen fermentation and the digestibility of feed rations in cattle and sheep . 2 . The digestibility of feed rations}; Jentsch W et al.; The results from 283 comparisons of digestibility in cattle (ox, cow, male and female young cattle) and sheep (adult wether) are presented . The crude protein content of the applied rations ranged from 90 to 340 and the crude fibre content from 80 to 430 g/kg DM . Within the range of rations with 200-350 g crude fibre per kg DM the differences between adult cattle and wether in the digestibility of energy and organic matter don't exceed 1%-unit (mean -0.5 +/- 2.5), that of crude protein is 5%-units lower in adult cattle than in adult wether . In young cattle digestibility is altogether lower than in wether; in young cattle with 120 to 200 kg live weight 4 to 6 and in more developed cattle 3 to 4 digestibility units for energy . In the metabolizability of the energy in comparison between adult wether and the different animal categories of cattle the difference don't exceed 1.5%-units . Relations between the live weight of cattle, the crude fibre of the rations as well as the nutrition level and the amount of difference of digestibility between cattle and sheep are considered.

Arch Tierernahr, 1993, 44(1), 21 - 7
{The effect of oligosaccharides on piglets}; Bolduan G et al.; Into the starter of weaned piglets 1% lactitol and 0.2% fructo-, isomalto- or galacto-oligosaccharides were added . After an adaptation period of two weeks the piglets were slaughtered 3 hours postprandial . Compared with control animals in the trial groups urea concentrations in the serum and fermentations in the stomach were lowered, stomach emptying rates increased . Higher volumes and contents were measured in the colon, especially in the upper half, and more lactic acid.

Chin J Biotechnol, 1993, 9(2), 123 - 9
Studies on caproic acid fermentation using immobilized cells; Yuan J et al.; Five carriers were tested for immobilizing caproic acid bacteria . The batch experiment results showed that the calcium alginate was the best one of the five immobilized materials . The characteristics of immobilized caproic acid bacteria cells were evaluated using a standard batch fermentation procedure . In the laboratory-scale experiments, the alginate beads could be maintained at least for 8 months with the yield of the caproic acid level about 11 mg/ml . Under optimum conditions, a maximum yield of caproic acid about 15 mg/ml could be obtained . The observed productive acid rate and its yield of immobilized cells appeared to be greater than that of the corresponding free cells suspension . The cell number per volume of immobilized cells was about ten times that of free cells.

Chin J Biotechnol, 1993, 9(2), 109 - 15
Modeling of the last stage of production phase of oxytetracycline fermentation processes; Xu C et al.; In an attempt to disclose the reason why, during the last stage of FBOFP (fed-batch oxytetracycline fermentation processes) its specific production rate in general decreases notably, the authors started with the modeling of the process based on operation data, and thus reached the conclusion that this is due to too low residual nitrogen in the substrate . This inference is quite unacceptable to the current practice of the process operations . It was finally realized that the trouble lies in that our old measurement method of residual nitrogen is misleading . Upon using improved measuring method, it was found that while the total residual nitrogen is plentiful, the available nitrogen notably decreases with time, and thus confirmed the authors' conclusions . Experiments on industrial fermentators showed that the product can be increased by 1%, and the titer reaches 3200 micrograms/ml.

Chin J Biotechnol, 1993, 9(1), 41 - 7
Extended Kalman filter (EKF) application in vitamin C two-step fermentation process; Wei D et al.; Based on kinetic model study of vitamin C two-step fermentation, the extended Kalman filter (EKF) theory is conducted for studying the process which is disturbed by white noise to some extent caused by the model, the fermentation system and operation fluctuation . EKF shows that calculated results from estimated process parameters agree with the experimental results considerably better than model prediction without using estimated parameters . Parameter analysis gives a better understanding of the kinetics and provides a basis for state estimation and state prediction.

Arch Med Res, 1993 Winter, 24(4), 333 - 8
Ethanol consumption during pregnancy and lactation . Changes in the nutritional status of predominantly breastfeeding mothers; Villalpando S et al.; The purpose of this investigation was to study the effects of ethanol, consumed as a mild fermented beverage called "pulque", during pregnancy and lactation on the food intake and some anthropometric indices of body composition of a group of lactating mothers in a town in central Mexico . Thirty two mothers who drank pulque during pregnancy and lactation and 61 non-drinking women with comparable characteristics were evaluated anthropometrically, their dietary and ethanol intake recorded during a 6-month postpartum period . Energy {(8360 +/- 2997 vs . 7156 +/- 2177 J) and protein (52.7 +/- 20.9 vs . 44.6 +/- 16.1 g)} 24-h intake, height, weight, body mass index, arm muscle and fat areas were greater in drinking mothers than in controls . Average total ethanol consumption varied from 0.48 - 0.55 g-1 kg-1.d-1 . Drinking mothers lost weight less frequently . Additional energy provided by pulque might explain such a difference . More precise information about the changes in their body composition and energy balance are in order for confirmation.

Ann Nutr Metab, 1993, 37(6), 311 - 9
Relationship between fermentations and calcium in the cecum of rats fed digestible or resistant starch; Younes H et al.; The present studies were undertaken to investigate the effects of the dietary calcium (Ca) level on the Ca balance and on large intestine physiology in rats fed diets providing carbohydrate as digestible wheat starch (DS) or resistant starch (RS) . Resistant starch was a high-amylose maize starch . The Ca level ranged from a marginally sufficient level (3 g/kg) to a level in excess of nutritional requirements (6 g/kg) . The cecal fermentations were more developed in rats fed RS diets and they were affected by the dietary Ca level, compared to rats fed the DS diets . In rats fed a low Ca RS diet, the cecal fermentations were more acidic than with a high Ca level and there was an accumulation of lactic acid together with depressed concentrations of short-chain fatty acids . There was a considerable accumulation of Ca and phosphate (Pi) in the cecum of rats fed the 6 g/kg level; on the other hand, the concentrations of minerals (Ca, Pi) were very low in the cecum of rats fed the low Ca RS diet . The proportion of soluble Ca in the cecum was markedly enhanced by active fermentations, especially in rats fed the high Ca RS diet (16.3 mmol/l) . In rats fed the RS diet, there was a substantial absorption of Ca from the cecum, which was relatively proportional to the dietary Ca level . The above data suggest that in these rats, Ca absorption in the large intestine made a substantial contribution to the digestive balance, probably at the expense of absorption in the upper part of the intestine.(ABSTRACT TRUNCATED AT 250 WORDS)

Ter Arkh, 1993, 65(11), 31 - 5
{The dynamics of the liver and myocardial enzymes in different forms of diphtheria in adults}; Fokina EG et al.; The authors studied changes in the levels of hepatic and myocardial enzymes in 89 patients with oropharyngeal diphtheria . The forms of the disease were different: carriage of the bacteria, local oropharyngeal diphtheria, toxic and subtoxic disease . Biochemical tests were also performed in 21 patients with lacunar angina . A correlation has been revealed between the intensity of fermentemia, its standing and the severity of the local lesions . Possible usage of biochemical markers is discussed for characterizing toxic diphtheria severity and prognosis of the disease.

Mamm Genome, 1993, 4(7), 368 - 73
Physical mapping of the lysozyme gene family in cattle; Gallagher DS Jr et al.; Amplification of an ancestral lysozyme gene in artiodactyls is associated with the evolution of foregut fermentation in the ruminant lineage and has resulted in about ten lysozyme genes in true ruminants . Hybridization of a cow stomach lysozyme 2 cDNA clone to restricted DNAs of a panel of cow x hamster hybrid cell lines revealed that all but one of the multiple bovine-specific bands segregate concordantly with the marker for bovine syntenic group U3 {Chromosome (Chr) 5} . The anomalous band was subsequently mapped to bovine syntenic group U22 (Chr 7) with a second panel of hybrids representing all 31 bovine syntenic groups . By two-dimensional pulsed-field gel electrophoresis the lysozyme genes on cattle Chr 5 were shown to be clustered on a 2- to 3-Mb DNA fragment, while the lactalbumin gene and pseudogenes that are paralogous and syntenic with the lysozymes were outside the lysozyme gene cluster . Chromosomal fluorescence in situ hybridization of a cocktail of lysozyme genomic clones localized the lysozyme gene cluster to cattle Chr 5 band 23, corroborating the somatic cell assignment.

Teratog Carcinog Mutagen, 1993, 13(2), 75 - 88
Sodium butyrate differentially modulates plasminogen activator inhibitor type-1, urokinase plasminogen activator, and its receptor in a human colon carcinoma cell; Reeder JA et al.; Human colonic epithelium is exposed to varying levels of sodium butyrate, which is derived from the bacterial fermentation of dietary carbohydrate . Sodium butyrate has several effects on colonic tumor cells in vitro, including arrest of cell growth and differentiation . In the present study we have found that, in addition to a reduction in cellular proliferation, sodium butyrate induces the transient expression of plasminogen activator inhibitor type-1 (PAI-1) in the LIM 2405 human colonic tumor cell . Approximately 40% of the PAI-1 secreted is biologically active as judged by the formation of higher molecular weight, SDS-resistant complexes with urokinase plasminogen activator (uPA) . The enhanced PAI-1 biosynthesis was accompanied by an increase in PAI-1 mRNA levels . During the same time period, the amount of secreted uPA remained relatively constant, but the level of cell associated uPA decreased slowly and was accompanied by a decrease in uPA mRNA levels . The uPA receptor is synthesized constitutively by these cells, and was down-regulated at both the protein and mRNA levels in response to sodium butyrate . The results demonstrate that sodium butyrate can alter the balance of components of the plasminogen activator system in a manner which favours net decreased plasminogen activator activity and suggests a role for sodium butyrate in the regulation of extracellular proteolysis.

Mol Biochem Parasitol, 1993 Jan, 57(1), 65 - 71
The effects of oxygen on fermentation in Giardia lamblia; Paget TA et al.; Detailed study of the effects of oxygen on the carbohydrate metabolism of Giardia lamblia revealed that low concentrations of oxygen (< 0.25 microM) produced profound alterations in the carbon balance of this organism . Although this concentration of oxygen could not be detected by mass spectrometry, a marked stimulation of ethanol production was observed . Associated with this was an inhibition of alanine production and oxidation of the intracellular NAD(P)H pool . Higher concentrations of oxygen inhibited ethanol production and further reduced levels of alanine . These results suggest that this stimulation is due to changes in carbon flux . Analysis of cell and medium hydrolysates after the growth of trophozoites in {U-14C}glucose suggests that G . lamblia does not synthesise detectable levels of labelled amino acids, except alanine and to a lesser extent valine, from this sugar . Trophozoites of G . lamblia have both glutamate dehydrogenase and alanine aminotransferase activity . As glutamate is taken up from the medium, it is suggested that glutamate dehydrogenase and alanine aminotransferase cooperate to convert pyruvate to alanine, with the concomitant oxidation of NAD(P)H.

Antonie Van Leeuwenhoek, 1993-94, 64(2), 121 - 35
Genetic organization of Acetobacter for acetic acid fermentation; Beppu T; Plasmid vectors for the acetic acid-producing strains of Acetobacter and Gluconobacter were constructed from their cryptic plasmids and the efficient transformation conditions were established . The systems allowed to reveal the genetic background of the strains used in the acetic acid fermentation . Genes encoding indispensable components in the acetic acid fermentation, such as alcohol dehydrogenase, aldehyde dehydrogenase and terminal oxidase, were cloned and characterized . Spontaneous mutations at high frequencies in the acetic acid bacteria to cause the deficiency in ethanol oxidation were analyzed . A new insertion sequence element, IS1380, was identified as a major factor of the genetic instability, which causes insertional inactivation of the gene encoding cytochrome c, an essential component of the functional alcohol dehydrogenase complex . Several genes including the citrate synthase gene of A . aceti were identified to confer acetic acid resistance, and the histidinolphosphate aminotransferase gene was cloned as a multicopy suppressor of an ethanol sensitive mutant . Improvement of the acetic acid productivity of an A . aceti strain was achieved through amplification of the aldehyde dehydrogenase gene with a multicopy vector . In addition, spheroplast fusion of the Acetobacter strains was developed and applied to improve their properties.

Patol Fiziol Eksp Ter, 1993 Jan-Feb, (1), 19 - 21
{Non-specific fermentemia as a possible cause of postoperative disorders of motor function of the small intestine}; Vasil'ev VN et al.; The authors studied duodenal myoelectric activity and the activity of trypsin, alpha 1-antitrypsin, alpha 2-macroglobulin, alpha-amylase, and kallikrein after 15-minute occlusion of the hepatic portal vein . The correlation was found between the activity of alpha 1-antitrypsin and the phases of the myoelectrical complex . It is concluded that the discharge of pancreatic proteases during an operative trauma may underlie the pathogenesis of postoperative inhibition of intestinal peristalsis.

Chin J Biotechnol, 1993, 9(3), 179 - 88
Mathematical model for citric acid fermentation; Hu J et al.; The kinetics for biomass proliferation, medium consumption and citric acid production in the course of citric acid fermentation were studied, and the mathematical models describing the course of citric acid fermentation were obtained in this paper . Based on the statistical data of experiment, the model was verified, and the model parameters were estimated with the results of the experiment . The results showed that the curves obtained by model calculation fitted with the ones determined by the experiments well, and the models described correctly the course of the citric acid fermentation . This is important for computer application to control the course of fermentation and realize the optimum of fermentation process.

Chin J Biotechnol, 1993, 9(3), 161 - 70
A flow dialysis cell for on-line measurement of glucose in fermentation broth; Zhang X et al.; A plate flow dialysis cell, employing an acetate cellulose ultrafiltration membrane, was designed and tested for applicability to on-line sampling in fermentation . The glucose contained in effluents of both sample stream channel (Channel A) and carrier stream channel (Channel B) was determined with an enzyme electrode flow injection analysis system . Glucose penetration rate was defined as Rp, Rp = Gb/(Ga + Gb), here Ga and Gb are glucose concentrations of effluent of channel A and B respectively . A higher penetration rate was obtained when using phosphate buffer (0.01M) as carrier solution instead of using distilled water . Operating pressure differences, temperature and residential time affected glucose penetration . Under the condition of 0.02MPa pressure differences and 0.23 min of residential time (12.8ml/L), Rp was about 12% in the range of 10-70mM with CV < 4% . When sample stream was yeast broth, the glucose penetration rate Rp was stable for at least 48 hr . Good relationship was observed between on-line and off-line sampling for glucose determination in yeast fermentation, the correlation coefficient r was 0.985.

Scand J Gastroenterol Suppl, 1993, 200, 80 - 6
The role of carbohydrate fermentation in colon cancer prevention; Van Munster IP et al.; Diet is an important factor in the development of colonic cancer . Fibre has been shown to decrease this risk . Part of this protective effect is probably mediated by colonic fermentation . About 10% of starch in the normal diet escapes digestion and absorption in the small bowel, and is therefore called resistant starch . This is a considerably larger source of fermentable substrate than fibre in the diet and could thus contribute significantly to the prevention of this malignancy . Short chain fatty acids, produced during fermentation, reduce colonic pH, affecting the intraluminal concentration of the putative co-carcinogenic secondary bile acids by precipitation, and by inhibition of their enzymatic formation from primary bile acids . The role of secondary bile acids in promoting colonic carcinogenesis is probably mediated by their cytotoxic effect on colonic mucosa, leading to a compensatory increase in proliferation . A hyper-proliferative mucosa, having an enhanced sensitivity to mutagenic substances, is associated with an increased risk of colorectal cancer . Butyrate, one of the short chain fatty acids, could be significant, as it has anti-neoplastic properties in vitro and in vivo . We conclude that fermentation is probably the key factor in the protective effect of fibre on colon carcinogenesis . Furthermore, consumption of resistant starch seems to be another way of stimulating fermentation.

Dakar Med, 1993, 38(1), 49 - 54
{Antihypertensive action of Parkia biglobosa+ (Jacq) Benth seeds in the rat}; Assane M et al.; Hundred white Wistar rats have been used to evaluate the antihypertensive effects of entire seeds and decorticated, fermented seeds of a soudanian plant, Parkia biglobosa . The arterial blood pressure was measured by using bloody method in anesthizied animals . The Pham Huu Chanh method was used to determine type plant's antihypertensive activity . According to the results obtained, in both preparations, adequate doses decrease arterial blood pressure, diastolic more than systolic, but the effect of fermented seeds was more important than the entire seeds . In the two cases, the decrease in blood pressure is greated in hypertensive than in normotensive subjects, and the hypotension induced was well correlated with a bradycardia.

Biotherapy, 1993-94, 7(2), 115 - 23
Enhancement of interferon-beta production with sphingomyelin from fermented milk; Osada K et al.; A fermented milk, Kefir, contains an active substance which enhances IFN-beta secretion of a human osteosarcoma line MG-63 treated with a chemical inducer, poly I: poly C . The active substance in the fermented milk was identified to be sphingomyelin (SpM) by a combined use of a fast atom bombardment mass spectrometry (FAB-MS) and a fast atom bombardment tandem mass spectrometry (FAB-MS/MS) . SpM from fermented milk (F-SpM) was a mixture of four molecular species of SpMs having C21-, C22-, C23- and C24-fatty acids . F-SpM enhanced the IFN secretion 14 times, SpMs from other sources also enhanced moderately (2-3 times) . Sphingosine and lysosphingomyelin also enhanced the activity but ceramide and cerebroside did not.

J Chem Technol Biotechnol, 1993, 58(4), 331 - 6
Aeration and mixing in vortex fermenters; Chisti Y et al.; The overall apparent volumetric gas-liquid mass transfer coefficient (kLa) and the mixing time (t95) were determined in a 240 dm3 vortex aerated fermenter over stirrer speed and air flow ranges of 300-800 rpm and 10-45 normal dm3 min-1, respectively . The mass transfer data obtained in an aqueous salt solution (2.5 kg m-3 NaCl in water) compared well with the measurements in a fermentation medium used in culture of certain microaerophilic bacteria . Over the ranges examined, the gas-liquid mass transfer coefficient depended only on air flow rate; the dependence was linear with flow . Mixing time declined with increasing agitation according to a power-law relationship . The mixing and mass transfer characteristics of the vortex aerated system were compared with that of a 'standard' stirred tank fermenter (27 dm3) . The mixing time variations with respect to agitation rate were remarkably similar for the two types of fermenters examined.

J Chem Technol Biotechnol, 1993, 58(2), 183 - 90
An automatic dehydrogenase-based flow-injection system: application for the continuous determination of glucose and lactate in mammalian cell-cultures; Becker T et al.; A concept for the development of an automatic flow-injection analyzer with integrated dehydrogenase columns and its application in the control of industrial processes is presented . The system is based upon a kernel consisting of a nested-loop injection unit, pumps for the filling of the injection loops and the transport of buffer and values for switching on the one hand between sample and standard solutions and on the other hand between different enzyme columns . A Microsoft Windows 3.x application 'WIN-FIA' controls interactively the whole system and can be easily adapted to a specific solution of an analytical problem . As an example, the flow-injection system was used for the continuous determination of glucose and lactate, using glucose dehydrogenase (GDH) and lactate dehydrogenase (LDH) as indicator enzymes, in a mammalian cell-culture fermentation process . The resulting concentration values are in good agreement with those obtained by discontinuously taken standard spectrophotometric enzyme assays.

Enzyme Microb Technol, 1993 Jan, 15(1), 66 - 71
Uses of beta-galactosidase tag in on-line monitoring production of fusion proteins and gene expression in Escherichia coli; Benito A et al.; A simple method for monitoring and quantifying automatically the production by fermentation of beta-galactosidase fusion proteins, making use of the remaining activity of the beta-galactosidase part, is considered . A hybrid protein carrying the major antigenic domain of foot-and-mouth disease virus C1 joined at the N-terminus of beta-galactosidase has been expressed in Escherichia coli . The yield of the chimeric protein has been monitored by flow injection analysis (FIA) during batch fermentations at laboratory scale, and a high correlation between values of product concentration from FIA and from immunological quantizations has been obtained . Because of the possibility of employing FIA in large-scale experiments, and the high sampling frequency, versatility, and reproducibility offered by this method, we propose FIA as a general, simple, quick, flexible, and reliable instrument for both monitoring the yield of recombinant proteins produced industrially, and performing basic research at laboratory scale.

J Chem Technol Biotechnol, 1993, 58(1), 77 - 9
Utilization of date products in production of oxytetracycline by Streptomyces rimosus; Abou-Zeid AZ et al.; The carbon and nitrogen sources of a synthetic fermentation medium were substituted by equivalent amounts of date-coat sugar extract and date-seed hydrolysate . The addition of 1.0 g dm-3 urea and date-seed lipid into the medium increased the efficacy for antibiotic formation . When the MgSO4, MnSO4, FeSO4 and ZnSO4 components of the medium were replaced by 0.5 g dm-3 date-seed ash, antibiotic output was also increased.

J Ind Microbiol, 1993 Jan, 12(1), 58 - 65
Production kinetics and stability properties of delta(L-alpha-aminoadipyl)-L-cysteinyl-D-valine synthetase from Streptomyces clavuligerus; Kadima TA et al.; Delta-(L-alpha-Aminoadipyl)-L-cysteinyl-D-valine (ACV)-synthetase is a key enzyme that channels primary metabolites to a tripeptide common to cephalosporin and cephamycin biosynthesis in Streptomyces clavuligerus . Time-course studies indicated that the S . clavuligerus ACV-synthetase was stable during the cephamycin C fermentation: the enzyme was produced early in the growth phase and its activity remained high up to 96 h of growth . The detection of crude ACV-synthetase activity in older cultures was best achieved with an assay medium supplemented with 5 mM phosphoenolpyruvate, at lower ATP concentrations . During storage at 4 degrees C, a progressive decrease in the stability of crude ACV-synthetase was observed with increasing culture age . Although a proteinolytic activity with a pH optimum at 8.2 was detected in crude cell-free extracts, no significant variation was observed in its activity with increasing culture age to account for the instability of ACV-synthetase in vitro . Addition of proteinase inhibitors did not improve the stability of the enzyme . However, a stabilization cocktail containing dithiothreitol, MgCl2, the three substrate amino acids, and glycerol increased the stability of the enzyme isolated from cultures grown for 30-40 h, which was shortly after the appearance of antibiotics in the culture fluid . This stabilized enzyme retained half of its initial activity after 6 days at 4 degrees C.

Res Commun Inst Ferment, 1993, (16), 18 - 23
Cross-contamination of cell lines as revealed by DNA fingerprinting in the IFO animal cell bank; Satoh M et al.; For quality control of cell lines, the Institute for Fermentation, Osaka (IFO) animal cell bank recently introduced DNA fingerprinting analysis, which enables verification of cell lines at the individual level, to detect cross-culture contamination . By using this analysis, we found two cases of cross-contamination of cell lines.

Biotechnol Prog, 1993 Jan-Feb, 9(1), 75 - 80
Bioprocess monitoring of dissolved oxygen using a computerized pulsing membrane electrode; Chen J et al.; A membrane oxygen electrode usually suffers from long-term signal deterioration due to environmental factors such as changes in hydrodynamic conditions and alteration of membrane oxygen diffusivity due to fouling . These problems can theoretically be overcome by the use of the same oxygen electrode in a pulsing mode . The effects of stirring rate, viscosity of the culture media, and addition of antifoam agents on the direct reading of this pulsing oxygen electrode were investigated, and the results were compared to the traditional pseudo-steady-state operation of the electrode . With a pulsing period controlled at 1 s and a rest period of longer than 5 min, the transient signal obtained can be quite stable, and it showed minimal interference from various environmental changes . Dissolved oxygen tension of a cephalosporin C fermentation was monitored using both this pulsing and the conventional pseudo-steady-state methods, and their readings were compared to those measured from an off-line newly calibrated oxygen electrode . The reading from the pulsed electrode showed more favorable agreement with that of the off-line measurement . The error encountered in using the conventional method of dissolved oxygen measurement could vary as much as 40% in comparison with the actual dissolved oxygen tension during a fermentation process.

J Chem Technol Biotechnol, 1993, 56(1), 35 - 40
Production of the enzyme dihydrofolate reductase by methotrexate-resistant bacteria isolated from soil; Nigam P et al.; Six bacterial cultures isolated from soil were capable of growing in the presence of methotrexate (MTX) . Two strains, PFR-1 and 3, developed resistance to 500 micrograms cm-3 MTX in the medium and produced elevated levels of the enzyme dihydrofolate reductase (EC 1.5.1.3): 2580 and 2702 U dm-3 compared to the sensitive parent strains (28 and 35 U dm-3) . Isolate PFR-3 showed maximum enzyme production (4950 U dm-3, specific activity 12.56 U mg-1 in flasks and 5737 U dm-3, specific activity 14.80 U mg-1 in 5-dm3 fermenter) during exponential phase of growth (6 h) at 37 degrees C and pH 7.0.

Enzyme Microb Technol, 1993 Jan, 15(1), 2 - 7
Physiological studies related to the immobilization of Penicillium chrysogenum and penicillin production; Mussenden P et al.; Using the production of penicillin by Penicillium chrysogenum as a model system, certain physiological aspects of immobilized and free cell cultures were compared . Reducing the immobilized viable spore loading (from 4 x 10(4) to 2 x 10(3) spores ml-1 gel) and initial bead diameter (from 3.5-4.0 to 1.5-2.0 mm) gave rise to an increase in the penicillin titer from 0.2 to 1.2 g l-1 . Using these conditions in immobilized cell culture the growth phase was prolonged and the duration of expression of the isopenicillin N synthase gene (pcbC) was significantly extended when compared with free cell culture (150 h as opposed to 100 h) . During the period of maximum penicillin production, different penicillin biosynthetic intermediates accumulated in the broth of free and immobilized cell cultures, reflecting a fundamental difference in cell physiology . Although the maximum specific productivity of penicillin production was reduced by immobilization, the average specific productivity increased when compared to free cell fermentation.

Cell Motil Cytoskeleton, 1993, 25(2), 111 - 28
DiOC6 staining reveals organelle structure and dynamics in living yeast cells; Koning AJ et al.; When present at low concentrations, the fluorescent lipophilic dye, DiOC6, stains mitochondria in living yeast cells {Pringle et al.: Methods in Cell Biol . 31:357-435, 1989; Weisman et al.: Proc . Natl . Acad . Sci . U.S.A . 87:1076-1080, 1990} . However, we found that the nuclear envelope and endoplasmic reticulum were specifically stained if the dye concentration was increased or if certain respiratory-deficient yeast strains were examined . The quality of nuclear envelope staining with DiOC6 was sufficiently sensitive to reveal alterations in the nuclear envelope known as karmellae . These membranes were previously apparent only by electron microscopy . At the high dye concentrations required to stain the nuclear envelope, wild-type cells could no longer grow on non-fermentable carbon sources . In spite of this effect on mitochondrial function, the presence of high dye concentration did not adversely affect cell viability or general growth characteristics when strains were grown under standard conditions on glucose . Consequently, time-lapse confocal microscopy was used to examine organelle dynamics in living yeast cells stained with DiOC6 . These in vivo observations correlated very well with previous electron microscopic studies, including analyses of mitochondria, karmellae, and mitosis . For example, cycles of mitochondrial fusion and division, as well as the changes in nuclear shape and position that occur during mitosis, were readily imaged in time-lapse studies of living DiOC6-stained cells . This technique also revealed new aspects of nuclear disposition and interactions with other organelles . For example, the nucleus and vacuole appeared to form a structurally coupled unit that could undergo coordinated movements . Furthermore, unlike the general view that nuclear movements occur only in association with division, the nucleus/vacuole underwent dramatic migrations around the cell periphery as cells exited from stationary phase . In addition to the large migrations or rotations of the nucleus/vacuole, DiOC6 staining also revealed more subtle dynamics, including the forces of the spindle on the nuclear envelope during mitosis . This technique should have broad application in analyses of yeast cell structure and function.

Cytobios, 1993, 73(294-295), 183 - 8
Hybrid construction by fusion of protoplasts of Endomycopsis fibuligera and Saccharomyces cerevisiae; Gautam SP et al.; Protoplasts of an ethanol-producing strain of Saccharomyces cerevisiae (rho-, Cyc R, Ket R) and amylase-producing yeast Endomycopsis fibuligera (rho+, Cyc S, Ket S) were fused, which resulted in starch fermenting hybrids . The fusion frequency was 2 x 10(-7) . The morphological appearance of the hybrids was similar to the petite parent S . cerevisiae strain . The amount of DNA in the hybrid was found to be slightly higher when compared with the individual parental strain.

Arch Tierernahr, 1993, 45(2), 111 - 29
{The influence of oral niacin doses during different dietary protein levels on indexes of rumen fermentation, blood parameters and fattening performance of young bulls}; Flachowsky G et al.; The influence of added niacin (0, 0.5 or 1 g per animal per day) and different crude protein contents (9.2 to 12.0% of DM) or the supply of various N-sources (urea, rape seed meal, soya bean meal, fish meal) were investigated on rumen fermentation, blood parameters, feed intake, weight gain and dry matter (DM) intake per weight gain in three individual feeding experiments with 156 growing bulls weighing between 175 and 300 kg per animal . Niacin supplementation did not significantly influence (P > 0.05) investigated parameters of rumen fermentation and blood . Ruminal propionate concentration increased insignificantly (from 18.9 to 19.5 moles per 100 moles on the average), inorganic P of blood serum somewhat decreased (from 2.98 to 2.82 mmol per 1) when niacin was added (P > 0.05) . Protein level did not significantly influence rumen fermentation and blood parameters except an increased urea concentration in the blood of cattle fed with diets richer in protein . The DM intake of control bulls and niacin supplemented animals amounted to 6.35 and 6.46 kg per animal per day on average . Influence of niacin on DM intake varied in dependence on protein source . The daily weight gain increased from 1003 (control) to 1040 g per animal per day (+ niacin, P > 0.05) . Niacin increased weight gain of bulls of urea (+ 43 g) and rape seed or soya bean meal added rations (+ 60 g per animal per day), but did not influence the weight gain in fish meal added rations . Increased weight gain resulted from ruminal and metabolic effects (about 2/3) as well as enhanced feed intake of bulls (about 1/3) . Feed efficiency mostly improved.

Acta Cient Venez, 1993, 44(5), 307 - 11
{Biomass production enriched in intracellular methionine by a mutant of Saccharomyces cerevisiae}; Albornoz IJ et al.; According with FAO reported data the methionine intracellular content in Saccharomyces cerevisiae is higher than another yeast . For increasing the yeast methionine internal concentration three S . cerevisiae mutant strains were chosen (M2, M4 y M9), obtained by ethionine (0.1 mg/ml) and norleucine (0.33 mg/ml) resistance by Gonzalez Miliani (personal communication) . The resistance levels in culture were modified until selection of a mutant LF-M9 etr norr, which shows resistance to ethionine (6 mg/ml) . Optimal conditions for growth were fixed on shaked flasks and later mutationaly experiments were conducted with nitrosoguanidine (0.5 mg/ml) and U.V . light (240 nm in 9 minutes d = 32 cm) . Mutants obtained were selected on plate replicates and microbiological test, using Escherichia coli 303 (Wollman, met- b1- strr) as the indicating strain . The mutant LF-M9 treo- etr norr, shows an intracellular methionine content 3 times higher than the control strain DSM D273-10B and 1.8 times higher than parental strain M9 . The mutant was cultivated on different agroindustrial wastes and the optimal growth was reached in acid hydrolysates of cassava foliage . Fermentations in 1 litre stirred fermentor were accomplished using these medium and the biomass obtained was 6.3 g of the yeast (dry weight) enriched in methionine per litre of extract.

Eur J Biochem, 1992 Dec 15, 210(3), 823 - 29
Characterization of a biologically active extracellular domain of fibroblast growth factor receptor 1 expressed in Escherichia coli; Bergonzoni L et al.; The functional features of a recombinant fibroblast growth factor (FGF) receptor (FGF-R) were investigated by expressing at high level in Escherichia coli a soluble non-glycosylated form of FGF-R1 . The extracellular domain of the mature protein (XC-FGF-R), comprising the first 356 amino acids, was purified from a large-scale fermentation . After cell lysis, the protein was quantitatively found in the pellet . XC-FGF-R was solubilized using guanidine/HCl and allowed to refold using two dialysis steps . The refolded protein was obtained in a homogeneous form after ammonium sulphate precipitation and gel-filtration chromatography . The soluble receptor had the ability to form a complex with recombinant human basic FGF (rhbFGF) in solution, as demonstrated by immunoprecipitation with anti-(FGF-R) serum . Formation of a rhbFGF/XC-FGF-R complex was visualized by cross-linking experiments . Quantitative binding experiments with the XC-FGF-R immobilized on Affi-Gel resin showed high binding affinity for 125I-bFGF (Kd = 5-10 nM) . Purified XC-FGF-R inhibited binding of 125I-bFGF to its high-affinity receptors on baby hamster kidney cells . These data suggest that glycosylation of the FGF-R is not necessary for its ligand-binding activity . The use of an E . coli expression system resulted in the efficient production of a soluble receptor in a form suitable for ligand/receptor structural studies and screening of new potential agonists and antagonists of angiogenesis . These results indicate that E . coli can be used for the production of complex molecules such as Ig-like receptors.

J Chromatogr, 1992 Dec 11, 584(1), 43 - 57
Rational design of purification processes for recombinant proteins; Leser EW et al.; This paper discusses the elements important for rational design of purification processes for recombinant proteins . Main issues involved in selection of operations and process design are reviewed with particular emphasis on the challenges posed by recombinant proteins . This includes thermodynamic characterization of target protein and main contaminants, use of correlations and of expert knowledge for the development of an expert system for optimization and design (selection) of separation and purification (chromatographic) processes . The main deficiency in accurate information for rational process selection is in that required for high-resolution chromatographic processes . The authors show that a database with detailed information on properties of the main contaminants present in the fermentation streams of usual recombinant protein sources can be integrated to an expert system with an open architecture . This will allow more precise selection of unit operations for the design of protein purification processes.

Nucleic Acids Res, 1992 Dec 11, 20(23), 6227 - 33
Molecular analysis of POP2 gene, a gene required for glucose-derepression of gene expression in Saccharomyces cerevisiae; Sakai A et al.; We have isolated a new mutant of Saccharomyces cerevisiae that exhibits a glucose-derepression resistant (and sucrose-non-fermentor) phenotype . This mutant was obtained by screening for overproduction of alpha-amylase in a strain containing the mouse alpha-amylase gene under the control of the PGK promoter . The mutation designated pop2 (PGK promoter directed over production) . The pop2 mutant overproduced amylase 5-6 fold and displayed several other pleiotropic defects: (1) resistance to glucose derepression, (2) temperature-sensitive growth, (3) failure of homozygous diploid cells to sporulate and (4) reduced amount of reserve carbohydrates . We mapped pop2 to chromosome XIV, distal to lys9 and SUP28, indicating that POP2 is a newly-identified locus . We isolated the POP2 gene from two yeast strains of different genetic backgrounds, S288C and A364A, and determined their nucleotide sequences . The predicted amino acid sequence of the POP2 protein contains three glutamine-rich region, a proline-rich region and a serine/threonine-rich region, characteristic of many transcription factors . Steady state levels of RNA transcribed from the PGK-amylase fusion gene and from endogenous PGK gene in stationary-phase pop2 cells were 5- to 10-fold higher than those observed in wild-type cells, showing that the pop2 mutation affects transcription of the PGK gene transcription.

J Antibiot (Tokyo), 1992 Dec, 45(12), 1914 - 8
Improved production of pentostatin and identification of fermentation cometabolites; Showalter HD et al.; A practical process is described for the large-scale isolation of pentostatin, an adenosine deaminase inhibitor used clinically for the treatment of interferon-refractory hairy cell leukemia . The identities of minor components in the fermentation beer, including 2'-deoxyguanosine, are also reported.

J Antibiot (Tokyo), 1992 Dec, 45(12), 1899 - 906
Dactylocyclines, novel tetracycline derivatives produced by a Dactylosporangium sp . II . Structure elucidation; Tymiak AA et al.; Fermentation of Dactylosporangium sp . (ATCC 53693) produces a mixture of tetracycline derivatives from which several related tetracycline glycosides, the dactylocyclines, were isolated and their structures determined . The most abundant glycoside in initial fermentations was found to be dactylocycline A . Each glycoside proved to be acid sensitive and readily hydrolyzed to a common aglycone, dactylocyclinone . While the aglycone was cross resistant with tetracycline, the dactylocyclines proved active against certain tetracycline-resistant organisms.

J Antibiot (Tokyo), 1992 Dec, 45(12), 1892 - 8
Dactylocyclines, novel tetracycline derivatives produced by a Dactylosporangium sp . I . Taxonomy, production, isolation and biological activity; Wells JS et al.; A screen for antibiotics with activity against tetracycline-resistant microorganisms has led to the isolation of Dactylosporangium sp . (ATCC 53693), a producer of several novel tetracycline derivatives . The major fermentation products, dactylocyclines A and B, were purified and MIC values determined against tetracycline-resistant and tetracycline-sensitive Gram-positive bacteria . The dactylocyclines represent the first naturally occurring tetracycline C2 amides which lack cross resistance with tetracycline.

J Antibiot (Tokyo), 1992 Dec, 45(12), 1853 - 66
Pneumocandins from Zalerion arboricola . I . Discovery and isolation; Schwartz RE et al.; HPLC bioautography of the directed biosynthesis of Zalerion arboricola led to the discovery of pneumocandin B0 (L-688,786), a new antifungal and anti-Pneumocystis carinii lipopeptide . Isolation techniques were developed to separate this component from pneumocandin A0 (L-671,329) in fermentations of a mutant of Zalerion arboricola . A number of related compounds were also isolated, which differ from pneumocandins A0 and B0 in the hydroxylation patterns on the ornithine, homotyrosine, and proline.

J Antibiot (Tokyo), 1992 Dec, 45(12), 1819 - 26
Dethymicin, a novel immunosuppressant isolated from an Amycolatopsis . Fermentation, isolation, physico-chemical properties and biological activities; Ueno M et al.; In the course of screening for immunomodulators inhibiting the mixed lymphocyte culture reaction (MLCR), we found a novel immunosuppressant, dethymicin in mycelium of Amycolatopsis mediterranei MI710-51F6 . From physico-chemical properties and biological activity it is different from immunosuppressants produced by microorganisms such as cyclosporins, FK506 and rapamycin . It inhibited immune responses in vitro and in vivo, and prolonged skin allograft in rats.

J Gen Microbiol, 1992 Dec, 138 ( Pt 12), 2559 - 66
Analysis of transcription and translation of glycolytic enzymes in glucose-limited continuous cultures of Saccharomyces cerevisiae; Sierkstra LN et al.; mRNA steady-state levels and activities of enzymes of intermediary carbon metabolism (hexokinase, phosphoglucoisomerase, phosphofructokinase, glucose-6-phosphate dehydrogenase, phosphoglucomutase) and glucose-regulated enzymes (pyruvate decarboxylase, pyruvate dehydrogenase, invertase, alcohol dehydrogenase) were determined in glucose-limited continuous cultures of an industrial strain of Saccharomyces cerevisiae at different dilution rates (D) ranging from 0.05 to 0.315 h-1 . The activity of most enzymes measured remained constant over this range except for alcohol dehydrogenase I/II which decreased proportionally with increasing dilution rate . A decrease in phosphoglucomutase activity occurred with increasing dilution rate but reached a minimum at D 0.2 h-1 and from thereon remained constant . A decrease in pyruvate decarboxylase activity and a slight decrease in phosphoglucoisomerase activity was observed . At D 0.29/0.315 h-1, at the onset of the Crabtree effect, most glycolytic enzymes remained constant except for pyruvate decarboxylase and glucose-6-phosphate dehydrogenase which increased at D 0.315 h-1 and alcohol dehydrogenase I/II which decreased . The ADHI/II and PDC1 mRNA levels obtained at the different dilution rates were in accordance with the activity measurements . The mRNA level of HXK1 decreased with increasing dilution rates, whereas the transcription of HXK2 increased . Pyruvate dehydrogenase (PDA1) and PGI1 mRNA fluctuated but no significant change could be detected . These results indicate that there is no transcriptional or translational regulation of glycolytic flux between D 0.05 h-1 and 0.315 h-1 except at the branch point between oxidative and fermentative metabolism (pyruvate decarboxylase/pyruvate dehydrogenase) at D 0.315 h-1 . Surprisingly regulation of the Crabtree effect does not seem to involve transcriptional regulation of PDA1.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunol Lett, 1992 Dec, 34(3), 273 - 8
Brief treatment with rapamycin in vivo increases responsiveness to alloantigens measured by the mixed lymphocyte response; Mohacsi PJ et al.; Rapamycin (RPM) is a macrolide fermentation product that prolongs rodent allograft survival more potently and effectively than cyclosporin A (CsA) and FK506 . Experiments in vitro have shown that RPM inhibits lymphoproliferation by mechanisms of action that are different from other immunosuppressants . Much less is known, however, about the effects of RPM on immune cells in vivo compared to other immunosuppressive drugs . Others have shown that in vivo treatment with CsA suppresses the responsiveness of cells in the mixed lymphocyte response (MLR) . Therefore, to investigate the effects of RPM in vivo, rats were treated with RPM and their lymphoid cells used as responder cells in the MLR . We confirmed that the proliferation of cells in the MLR was decreased after treatment with CsA in vivo . In contrast, treatment with RPM in vivo greatly increased the proliferative response to alloantigen in the MLR . These findings show that the effects of RPM and CsA on immune cells in vivo differ . Perhaps the cells proliferating in the MLR after in vivo RPM treatment play a role in the regulation of the immune system that enables this immunosuppressant to prolong allograft survival so effectively in rodents.

J Clin Pathol, 1992 Dec, 45(12), 1075 - 8
Strains of Escherichia coli O157:H8 from human diarrhoea belong to attaching and effacing class of E coli; Scotland SM et al.; AIMS: To determine whether 17 Escherichia coli O157:H8 strains isolated from patients with diarrhoea in the United Kingdom were putative pathogens . METHODS: The strains had been isolated by the use of O157 antiserum, available for the detection of Vero cytotoxin (VT) producing strains of E coli O157 that are usually of flagellar (H) type 7, but may also be non-motile . The strains were examined for VT production, for their ability to adhere to HEp-2 cells, and for hybridisation with several DNA probes that recognise pathogenic properties of E coli . Their ability to ferment sorbitol and to produce beta-glucuronidase was also investigated, as these tests are used to discriminate VT positive O157 strains . RESULTS: The O157:H8 strains did not produce VT . All gave localised attachment to HEp-2 cells, associated with a positive fluorescence-actin staining test, and all hybridised with the E coli attaching and effacing (eae) probe . In addition to the difference in VT production, O157:H8 strains could be distinguished from VT positive O157 strains by their beta-glucuronidase activity, their failure to produce enterohaemolysin, and their lack of hybridisation with the CVD419 probe derived from a plasmid in an O157:H7 strain . CONCLUSIONS: The 0157:H8 strains had in vitro properties characteristic of the class of E coli that causes attaching and effacing lesions in epithelial intestinal cells . They may therefore be considered a putative cause of diarrhoea but their prevalence remains to be established . Several O157:H8 strains failed to ferment sorbitol in agar plates and therefore could be misidentified as VT positive O157 strains . Confirmatory tests for VT production are needed when O157 strains are isolated from faeces.

Biotechnol Appl Biochem, 1992 Dec, 16(3), 275 - 86
Effects of T-2 toxin on ethanol production by Saccharomyces cerevisiae; Koshinsky HA et al.; A trichothecene mycotoxin, T-2 toxin, inhibits several aspects of cellular physiology in Saccharomyces cerevisiae, including protein synthesis and mitochondrial functions . We have studied growth of, glucose utilization by, and ethanol production by S . cerevisiae and show that they are inhibited by T-2 toxin between 20 and 200 micrograms/ml in a dose-dependent manner . At 200 micrograms/ml, T-2 toxin causes cell death . This apparent inhibition of ethanol production was found to be the result of growth inhibition . On the basis of biomass or glucose consumption, T-2 toxin increased the amount of ethanol present in the culture . This suggests that T-2 inhibits oxidative but not fermentative energy metabolism by inhibiting mitochondrial function and shifting glucose catabolism toward ethanol formation . As T-2 toxin does not directly inhibit ethanol production by S . cerevisiae, this system could be used for ethanol production from trichothecene-contaminated grain products.

J Anim Sci, 1992 Dec, 70(12), 3899 - 908
Alternate day supplementation of corn stalk diets with soybean meal or corn gluten meal fed to ruminants; Collins RM et al.; Four experiments were conducted to determine the effect of adding corn gluten mean (CGM) or soybean meal (SBM) at 24- or 48-h intervals to diets based on corn stalks . In each experiment corn stalks was the primary diet ingredient fed to wethers or steers . Monensin was also fed to determine whether its effects on ruminal fermentation would improve the efficiency of N utilization under these conditions . Evaluation criteria included ruminal fermentation characteristics, DM intake and utilization, N balance in sheep, and steer feedlot performance . Ruminal ammonia nitrogen (NH3 N) concentrations measured over time were higher (P < .05) when diets contained SBM . Diet did not influence (P > .10) total VFA concentrations in ruminal fluid . Differences in diurnal shifts in ruminal NH3 N and total VFA due to protein source resulted in diet x hour interactions (P < .05) . Dry matter intake response to protein source and frequency of supplement feeding was variable . Dry matter digestibility and nitrogen digestibility were not affected (P > .10) by protein source or feeding interval . The 48-h interval feeding of CGM was favorable compared with 24-h interval feeding (P < .05) . The opposite response occurred with SBM, resulting in a diet x feeding interval interaction (P < .05) . Nitrogen retention was greater (P < .05) when CGM was fed and with alternate day feeding . Diets that contained CGM supported higher (P < .05) ADG and gain/feed than diets that contained SBM when fed to steer calves . Alternate day feeding of supplements that contained monensin was detrimental to steer performance under the conditions of these experiments . Corn gluten meal is an effective substitute for SBM when alternate day protein supplementation is practiced.

J Clin Microbiol, 1992 Dec, 30(12), 3112 - 6
Evaluation of the RapID ANA II and API ZYM systems for identification of Actinomyces species from clinical specimens; Brander MA et al.; Classification and identification of fermentative actinomycetes are labor-intensive and problematic . In this study, we evaluated the applicability and reliability of the RapID ANA II system (Innovative Diagnostic Systems, Inc., Atlanta, Ga.) and the discriminatory value of the API ZYM system (Societes Analytab Products Inc., La Balme Les Grottes, France) in the identification of Actinomyces-like bacteria by using conventional methods as a reference . Eighty-five strains, including 71 isolates from mixed anaerobic infections and 14 reference strains, were tested . The RapID ANA II system correctly identified all Actinomyces odontolyticus strains and 65% of Actinomyces israelii strains . All Arcanobacterium haemolyticum strains were misidentified as Actinomyces pyogenes . The most common isolates in the study were Actinomyces meyeri-like organisms, 84% of which, however, were aerotolerant . The identification of these aerotolerant strains thus remains unresolved and warrants further studies . New characteristics and changes to the conventional API ZYM enzyme profiles are suggested . The API ZYM enzyme profiles of A . odontolyticus and A . israelii were very similar, the only discriminating enzyme being alpha-fucosidase . In differentiation between A . pyogenes and Arcanobacterium haemolyticum, the production of beta-glucuronidase by the former and the production of acid phosphatase by the latter are suggested as new helpful characteristics for use in clinical laboratories . In summary, the RapID ANA II and API ZYM systems can be used as rapid preliminary methods in the identification of Actinomyces species but accurate identification requires supplementary conventional tests and gas-liquid chromatography.

Biosci Biotechnol Biochem, 1992 Dec, 56(12), 1949 - 54
Purification and primary structure of proteinous alpha-amylase inhibitor from Streptomyces chartreusis; Katsuyama K et al.; A new polypeptide inhibitor, AI-409, that inhibits human salivary alpha-amylase, was purified from a fermentation broth of Streptomyces chartreusis strain No . 409 . This protein consists of a single-chain polypeptide of 78 amino acid residues, and includes two disulfide bridges . The primary structure of AI-409 and the locations of the disulfide bridges were identified by enzymatic digestion and the automatic Edman technique . Enzymatic digestion was done with trypsin, carboxypeptidase Y, and chymotrypsin . One of the disulfide bridges was between Cys(10) and Cys(26), and the other between Cys(44) and Cys(71).

Arch Latinoam Nutr, 1992 Dec, 42(4), 451 - 5
{Nutritional evaluation of rice flour fermented with Rhizopus oligosporus}; Canniatti-Brazaca SG et al.; In order to increase the proteic content of rice meal, fermentation with Rhizopus oligosporus was performed . During fermentation, samples were taken at the times of 0,20,30,40,50,60,70 and 80 hours . These samples were oven dried and further analysed . The amino acid composition of rice meal had lysine and threonine the most limiting ones . After fermentation the lysine content increase and the more limiting were the sulfur amino acids methionine and cystine (76.04%), threonine (91.03%) and lysine (97,04% . With the aim of verifying the biological value of the protein a bioassay was carried out . The fermented rice meal presented a higher digestibility value and the net protein utilization for the fermented rice meal lower than for the non fermented one.

Yeast, 1992 Dec, 8(12), 1077 - 87
Analysis of glucose repression in Saccharomyces cerevisiae by pulsing glucose to a galactose-limited continuous culture; Sierkstra LN et al.; In this study, glucose repression in Saccharomyces cerevisiae was analysed under defined physiological conditions, at both the molecular and physiological levels, by pulsing glucose to a galactose-limited continuous culture . During this pulse of glucose, the galactose feed was kept constant . Directly after the glucose pulse, carbon dioxide production increased while oxygen consumption remained constant, demonstrating that the surplus of glucose had been consumed by means of fermentation . The direct accumulation of galactose in the medium after the glucose pulse indicated that the consumption of galactose had been stopped instantaneously . Galactose uptake experiments revealed that the galactose transporter was still present but apparently was incapable of galactose uptake, which could be due to inhibition of the galactose transporter by glucose . The total concentration of cAMP increased from 5 nmol g-1 at t = 0 to 25 nmol g-1 at t = 1.5 min . After 2 min the concentration of cAMP gradually decreased again to the normal level . Within 2 min after the addition of glucose, the transcription of the GAL genes and SUC2 was inhibited . In addition, the transcription of the HXK1 gene, encoding hexokinase isoenzyme 1, was also inhibited, which demonstrates that the HXK1 gene is regulated at the transcriptional level comparable with invertase.

J Dairy Sci, 1992 Dec, 75(12), 3531 - 8
Sodium bicarbonate and yeast culture effects on ruminal fermentation, growth, and intake in dairy calves; Quigley JD 3rd et al.; Sodium bicarbonate and yeast culture effects on ruminal fermentation, intake, and growth were evaluated in young calves . In trail 1, nine ruminally cannulated Holstein calves averaging 12 wk of age were fed control starter (17% CP) or starters containing 3% sodium bicarbonate or .2% yeast (Saccharomyces cerevisiae) culture in a 3 x 3 Latin square . Calves were fed for ad libitum consumption for 10 d and then at 85% of ad libitum intake to d 14 . Ruminal fluid taken at 0 h postfeeding tended to have higher pH and a greater proportion of acetate when calves were fed sodium bicarbonate, but other ruminal and blood parameters did not differ among treatments . By 4 h after feeding, ruminal VFA had increased to 120.7 mM, molar proportions of individual acids were altered, and blood ketones and VFA increased in treated calves . In trial 2, 42 Jersey calves were fed experimental starters for ad libitum consumption during a 12-wk study . Calves began the study at 3 to 5 d of age . There were no significant effects of yeast culture or sodium bicarbonate on DMI or intake of starter, rates of gain, or feed efficiency . Plasma urea N was reduced when sodium bicarbonate was fed . Both sodium bicarbonate and yeast culture affected blood and ruminal metabolites when calves were limit-fed but did not influence intake or daily gain when calves were fed for ad libitum consumption.

Antibiot Khimioter, 1992 Dec, 37(12), 26 - 8
{Selection of Penicillium chrysogenum--producer of penicillin with several valuable technologic features}; Rusinov SF; The efficiency of the routine methods for improvement of P . chrysogenum providing specific selection by several features with testing one of them was studied . A new highly potent strain of P . chrysogenum producing phenoxymethylpenicillin was isolated . The strain is characterized by a shorter fermentation cycle, lower viscosity of the fermentation broth and capacity for synthesizing 32,600 units/ml of phenoxymethylpenicillin under industrial conditions (in a lactose medium) by the 97th hour of the cultivation in fermenters with energy consumption of 1.3 kW . The increased amylolytic activity of the strain and the decreased viscosity of the fermentation broth provided using of the fermentation media containing 3.5 per cent of corn meal.

Aust J Public Health, 1992 Dec, 16(4), 387 - 96
Evaluating the petrol-sniffing prevention programs of the Healthy Aboriginal Life Team (HALT)
Bryce S, Rowse T, Scrimgeour D.
The evaluation of the Healthy Aboriginal Life Team's (HALT) petrol-sniffing prevention programs at Yuendumu, Kintore and the Pitjantjatjara Lands first required a specification of program outcome--which was not changed in the enumerated prevalence of petrol sniffing, but alteration in parental perceptions of the relevance and effectiveness of families' nurturant authority over recalcitrant youngsters . The evaluation then proceeded by a series of interviews with resident or ex-resident adults (Aboriginal and non-Aboriginal) of Yuendumu, Kintore, Kiwirrkurra, Ernabella, Indulkana and Fregon . Adults articulated their efficacy in different ways in each place . Some favoured the conclusion that HALT had helped them, others clearly identified HALT as an obstacle to or a distraction from the implementation of other preventive and curative community-based action . We discerned a ferment of cultural adjustment in the distribution of authority over children among parents and welfare agencies . We caution against finding in HALT's successes a model procedure for benign interventions into such cultural adjustment.

Semin Cancer Biol, 1992 Dec, 3(6), 383 - 90
Pharmacological probes of Ras function; Gibbs JB; Numerous approaches toward anti-ras drugs are being explored . Efforts range from cell-based assays which screen fermentation products to more structural or mechanism-based in vitro screening and design . For the mechanism-based approaches, extensive research efforts on the function and regulation of the ras oncogene protein have identified potential points of intervention, including protein expression, membrane localization, guanine nucleotide activation, and interaction with effector systems.

Ann N Y Acad Sci, 1992 Nov 30, 672, 510 - 27
New developments in the synthesis of natural and unnatural amino acids; Kamphuis J et al.; Amino acids play an important role in biochemistry and chemistry . They are the building blocks of proteins and play an essential role in the regulation of the metabolism of living organisms . In general, it can be stated that microbial processes (fermentation) are the industrial production methods of choice for large-scale production of naturally occurring proteinogenic L-alpha-H-amino acids, while for the production of synthetic D- and/or L-alpha-H-amino acids, several other methods are highly competitive . At DSM, several routes, i.e., (chemoenzymatic) synthesis, towards L-alpha-H and D-alpha-H-amino acids have been elaborated since the midseventies . A general process for the synthesis of natural as well as synthetic optically pure amino acids has been developed, using an enzymatic kinetic resolution step on racemic amino acid amides as the key step . In this case, both enantiomers of the alpha-H-amino acids are prepared in one single step . This process has been commercialized since 1988 . More recent developments using L- or D-amino peptidases in combination with amino acid amide racemases and an asymmetric transformation concept are discussed.

Ann N Y Acad Sci, 1992 Nov 30, 672, 444 - 50
Preparative enzymatic synthesis of activated neuraminic acid by using a microbial enzyme; Kittelmann M et al.; Using Escherichia coli K-235 as a production strain in a fed-batch fermentation process with an optimized sorbitol/yeast extract medium, we were able to produce 640 U of CMP-Neu5Ac synthetase in 10 l scale (64 U/l) and 9200 U (total enzyme) in 200 l scale (390 U/kg wet weight) . By simple one-step purification procedures, enzyme preparations were obtained that could be used efficiently for the synthesis of CMP-Neu5Ac from CTP and Neu5Ac with over 90% yield, from Neu5Ac, CMP, and ATP or phosphoenolpyruvate by in situ generation of CTP, and from CTP, pyruvate, and ManNAc or GlcNAc by in situ generation of Neu5Ac.

FEBS Lett, 1992 Nov 30, 313(3), 251 - 4
Deletion of subunit 9 of the Saccharomyces cerevisiae cytochrome bc1 complex specifically impairs electron transfer at the ubiquinol oxidase site (center P) in the bc1 complex; Graham LA et al.; Deletion of QCR9, the nuclear gene encoding subunit 9 of the mitochondrial cytochrome bc1 complex in Saccharomyces cerevisiae, results in inactivation of the bc1 complex and inability of the yeast to grow on non-fermentable carbon sources . The loss of bc1 complex activity is due to loss of electron transfer activity at the ubiquinol oxidase site (center P) in the complex . Electron transfer at the ubiquinone reductase site (center N), is unaffected by the loss of subunit 9, but the extent of cytochrome b reduction is diminished . This is the first instance in which a supernumerary polypeptide, lacking a redox prosthetic group, has been shown to be required for an electron transfer reaction within the cytochrome bc1 complex.

J Antibiot (Tokyo), 1992 Nov, 45(11), 1709 - 16
Cochinmicins, novel and potent cyclodepsipeptide endothelin antagonists from a Microbispora sp . I . Production, isolation, and characterization; Lam YK et al.; Cochinmicins I, II, III are novel peptolides produced in submerged-fermentation cultures of Microbispora sp . ATCC 55140 . These closely related compounds are separated by HPLC and are novel competitive endothelin antagonists . Cochinmicins II and III are stereoisomeric to each other . Cochinmicin I is the deschloro analog of cochinmicin III.

Nucleic Acids Res, 1992 Nov 11, 20(21), 5677 - 86
Differentially regulated malate synthase genes participate in carbon and nitrogen metabolism of S . cerevisiae; Hartig A et al.; We have isolated a second gene (MLS1), which in addition to DAL7, encodes malate synthase from S . cerevisiae . Expression of the two genes is specific for their physiological roles in carbon and nitrogen metabolism . Expression of MLS1, which participates in the utilization of non-fermentable carbon sources, is sensitive to carbon catabolite repression, but nearly insensitive to nitrogen catabolite repression . DAL7, which participates in catabolism of the nitrogenous compound allantoin, is insensitive to carbon catabolite repression, but highly sensitive to nitrogen catabolite repression . Results obtained with null mutations in these genes suggest that S . cerevisiae contains at least one and perhaps two additional malate synthase genes.

Gene, 1992 Nov 2, 121(1), 167 - 71
The phenotype of a dihydrofolate reductase mutant of Saccharomyces cerevisiae; Huang T et al.; We have constructed a dihydrofolate reductase mutant (dfr1) of Saccharomyces cerevisiae . The mutant has auxotrophic growth requirements for the C1 metabolites dTMP, adenine, histidine and methionine, similar to those of wild-type (wt) strains grown in the presence of methotrexate (MTX) . However, unlike wt strains treated with MTX, the growth requirements of the dfr1 mutant are not satisfied by exogenous 5-formyltetrahydrofolic acid (FA; folinic acid) in complex (YEPD) medium . This result is surprising, as yeast cells treated with MTX are expected to be phenocopies of dfr1 mutants . The inability of the mutants to metabolize FA suggests that the DFR1 gene product may have a role in folate metabolism in addition to its well-characterized function in the reduction of dihydrofolate . From dfr1 strains, we have isolated secondary mutants whose growth can be supported by FA in YEPD medium . This FA-utilizing phenotype is attributable to recessive mutations which we have designated fou . In addition to their inability to metabolize FA, the dfr1 strains are unable to grow on medium containing the non-fermentable carbon source glycerol, suggesting that the DFR1 gene product is also required for mitochondrial function . In order to overcome this lack of respiratory activity in the dfr1 mutants, we isolated strains containing a dominant mutation, DIR, which allows growth on glycerol in the presence of antifolate drugs . When crossed into dfr1 strains, the DIR mutation conferred respiratory competence . These strains should be useful in a variety of studies on the genetics and biochemistry of folate metabolism in this simple eukaryote.

Environ Health Perspect, 1992 Nov, 98, 199 - 202
Use of breath hydrogen and methane as markers of colonic fermentation in epidemiologic studies: circadian patterns of excretion; Le Marchand L et al.; Fermentation in the large bowel has been postulated to play a protective role against colon cancer . Hydrogen and methane are end products of this fermentation process and are absorbed into the bloodstream and excreted via expired air in the breath . Breath levels of hydrogen and, to a lesser extent, methane correlate strongly with colonic fermentation and may serve as useful biomarkers for this process . In a preliminary study to assess the usefulness of these two markers in epidemiologic studies, we followed the hourly excretion of the two gases in expired alveolar air for 48 hr in 20 healthy subjects, using a Quintron gas chromatograph equipped with a solid-state detector specific for reducing gases . All subjects excreted hydrogen, but 71% did not excrete methane . Possible atmospheric contamination of the samples was corrected for on the basis of breath carbon dioxide levels . A clear circadian pattern of excretion was observed for breath hydrogen, with a decrease during the early morning followed by a progressive increase during the rest of the day . Methane excretion was constant throughout the day . This study shows that four samples collected at convenient times (0600, 1300, 1800, and 2200 hr) are optimal to characterize individuals by their breath excretions of hydrogen and methane during a 24-hr period.

J Nat Prod, 1992 Nov, 55(11), 1582 - 7
A colorimetric microassay for the detection of agents that interact with DNA; Burres NS et al.; A simple microtiter assay for the detection of compounds that bind DNA is described . Agents that displace methyl green from DNA are detected spectrophotometrically by a decrease in absorbance at 630 nm . The feasibility of using the assay for detecting DNA-active compounds in fermentation extracts was assessed, and the activities of reference compounds in the methyl green assay and an ethidium bromide displacement method were compared.

Mol Biochem Parasitol, 1992 Nov, 56(1), 79 - 88
Influence of oxygen on the fermentative metabolism of metronidazole-sensitive and resistant strains of Trichomonas vaginalis; Ellis JE et al.; The microaerophilic protozoon Trichomonas vaginals responds to extracellular changes in oxygen concentration: acetate, lactate, ethanol, H2 and CO2 formation, as well as glucose-depletion rates, are affected . All these variables except ethanol production rates, also differed between clinically metronidazole-sensitive (1910) and resistant (IR78 and CDC85) strains . Most interesting were the greatly increased glucose-scavenging rates of resistant isolates and their low specific activities of hydrogenase and H2 formation rates by comparison with the metronidazole-sensitive strain . Results suggest that all three strains of this parasite are well adapted to the O2 levels prevailing in situ (13-56 microM) . Thus, vaginal oxygen tensions have more pronounced effects on the balances of fermentation products in the resistant strains, and results indicate that these strains may then use hydrogenosomal pathways to their advantage.

AIDS, 1992 Nov, 6(11), 1287 - 92
Serological responses to mycoplasmas in HIV-infected and non-infected individuals; Hakkarainen K et al.; OBJECTIVE: To assess the frequency of mycoplasma infections in HIV-antibody-positive and -negative individuals by studying the serological responses against mycoplasmas, especially Mycoplasma fermentans and M . pirum . DESIGN: An enzyme-linked immunosorbent assay (ELISA) was used to measure immunoglobulin G (IgG) class antibody concentrations against six mycoplasma species in sera of HIV-positive and HIV-negative individuals . METHODS: Serum samples were obtained from 30 HIV-positive individuals (10 asymptomatics, 10 with lymphadenopathy syndrome and 10 with AIDS), 10 HIV-negative partners of HIV-positive individuals and 40 HIV-negative blood donors . Antibodies to M . fermentans strains incognitus and PG18, M . pirum, M . genitalium, M . pneumoniae and M . hominis were assessed by immunoblot or ELISA . Absorbance values were taken as a semiquantitative measurement for antibody concentration and an arbitrary cut-off value (0.8) was set to establish seroprevalence . RESULTS: There was no significant difference in the mean IgG concentrations of any of the six mycoplasmas between HIV-positive and HIV-negative groups . Antibody concentrations were also similar in different clinical phases of HIV infection . Antibody concentrations to different mycoplasma strains were compared with each other to reveal eventual cross-reactions caused by shared antigens; the strongest correlation (r = 0.836) was found between M . fermentans strains incognitus and M . pirum antibody concentrations . The correlation between M . fermentans strains incognitus and PG18 was also significant but weaker (r = 0.522) . No shared antigens between M . fermentans strain incognitus and M . pirum were demonstrated by immunoblot . CONCLUSIONS: Antibodies against M . fermentans type strain PG18, strain incognitus and against M . pirum are detected infrequently and their presence does not correlate with HIV infection per se or with the clinical stage of HIV infection.

J Antibiot (Tokyo), 1992 Nov, 45(11), 1723 - 32
Matlystatins, new inhibitors of typeIV collagenases from Actinomadura atramentaria . I . Taxonomy, fermentation, isolation, and physico-chemical properties of matlystatin-group compounds; Ogita T et al.; During the course of a screening for inhibitors of typeIV collagenases, new metabolites, designated matlystatins, have been isolated from an actinomycete strain, which was identified as a strain of Actinomadura atramentaria . Matlystatins were composed of five congeners, which were separated and purified by n-butanol extraction and chromatography.

J Dairy Sci, 1992 Nov, 75(11), 3056 - 65
Effect of yeast culture supplement on production, rumen fermentation, and duodenal nitrogen flow in dairy cows; Erasmus LJ et al.; Six lactating Holstein cows fitted with rumen and T-type duodenal cannulas were used in a crossover design to examine effects of yeast culture supplement on production parameters, rumen fermentation, and flow of N to the duodenum . Treatments were control and control plus 10 g/d of yeast culture . Dry matter intake was greater, and milk production tended to be higher, for cows supplemented with yeast culture, but milk composition was not affected . Rumen pH was not affected by yeast culture, but peak lactic acid concentration decreased from 1.93 to 1.73 mM . Rumen fluid acetate:propionate ratio, dilution rate (percentage per hour), and ammonia N concentration (milligrams per deciliter) were 2.28, .12, and 10.7 and 2.04, .13, and 9.6 for control cows and for cows supplemented with yeast culture, respectively . Although numbers of fiber-digesting bacteria were not affected by yeast culture, DM disappearance of wheat straw tended to be higher at 12 and 24 h, and CP and ADF digestibilities were greater . Duodenal NAN flow tended to be higher in cows supplemented with yeast culture because of higher bacterial N flow . Duodenal AA profile and flow of Met were significantly affected by yeast culture supplementation . The results suggest that yeast culture may alter the AA profile of bacterial protein.

J Dairy Sci, 1992 Nov, 75(11), 2990 - 3002
Effects of feeding diets containing calcium salts of long-chain fatty acids to lactating dairy cows; Schauff DJ et al.; Four cows were utilized in a 4 x 4 Latin square design to investigate the effects of feeding Ca salts of long-chain fatty acids . Treatments were control diet with 1) no added fat, 2) 3% Ca salts of long-chain fatty acids, 3) 6% Ca salts of long-chain fatty acids, and 4) 9% Ca salts of long-chain fatty acids . Cows were fed chopped alfalfa hay, alfalfa haylage, corn silage, and concentrate (15:22:13:50) on a DM basis . Dry matter intake, energy intake, and ruminal fermentation were not altered greatly until Ca salts of long-chain fatty acids constituted 9% of DMI . Digestibilities of DM, OM, ADF, NDF, and hemicellulose were not affected by treatment . Digestibilities of cellulose, soluble residue, total C18 fatty acids, and total fatty acids followed quadratic patterns . Absorption of N was increased linearly when fat was fed, but digestibility of Ca was decreased linearly . Milk production, CP, and SNF were not altered greatly by inclusion of 3 or 6% Ca salts of long-chain fatty acids in the diet, but inclusion of 9% Ca salts of long-chain fatty acids decreased their production . Calcium salts of long-chain fatty acids increased milk fat percentage and production of fat and FCM when fed as 3 or 6% of the dietary DM but decreased yields of milk fat and FCM when fed as 9% . Calcium salts of fatty acids can be fed to provide up to 6% of the dietary DM without deleterious effects on ruminal fermentation and digestibilities of most nutrients.

J Anim Sci, 1992 Nov, 70(11), 3551 - 61
A net carbohydrate and protein system for evaluating cattle diets: I . Ruminal fermentation; Russell JB et al.; The Cornell Net Carbohydrate and Protein System (CNCPS) has a kinetic submodel that predicts ruminal fermentation . The ruminal microbial population is divided into bacteria that ferment structural carbohydrate (SC) and those that ferment nonstructural carbohydrate (NSC) . Protozoa are accommodated by a decrease in the theoretical maximum growth yield (.50 vs .40 g of cells per gram of carbohydrate fermented), and the yields are adjusted for maintenance requirements (.05 vs .150 g of cell dry weight per gram of carbohydrate fermented per hour for SC and NSC bacteria, respectively) . Bacterial yield is decreased when forage NDF is < 20% (2.5% for every 1% decrease in NDF) . The SC bacteria utilize only ammonia as a N source, but the NSC bacteria can utilize either ammonia or peptides . The yield of NSC bacteria is enhanced by as much as 18.7% when proteins or peptides are available . The NSC bacteria produce less ammonia when the carbohydrate fermentation (growth) rate is rapid, but 34% of the ammonia production is insensitive to the rate of carbohydrate fermentation . Ammonia production rates are moderated by the rate of peptide and amino acid uptake (.07 g of peptide per gram of cells per hour), and peptides and amino acids can pass out of the rumen if the rate of proteolysis is faster than the rate of peptide utilization . The protein-sparing effect of ionophores is accommodated by decreasing the rate of peptide uptake by 34% . Validation with published data of microbial flow from the rumen gave a regression with a slope of .94 and an r2 of .88.

Dtsch Tierarztl Wochenschr . 1992 Nov;99(11):464.
Monensin poisoning in dromedary camels; Mousa HM et al.; Four female fistulated camels (Camelus dromedarius), 4-5 years of age, were each given two grams of 10% monensin intraruminally daily for six days to study the effect of monensin on the rumen fermentation pattern . Signs of toxicity appeared on the sixth day, and included depression, anorexia, muscular weakness, inability to stand, salivation and regurgitation of ruminal contents . On the eighth day, two animals died . The ruminal contents were replaced in the survivors, but they died on the tenth and eleventh day from the start of the experiment.

Am J Physiol, 1992 Nov, 263(5 Pt 1), E1002 - 9
In vivo estimation of lactose hydrolysis in premature infants using a dual stable tracer technique; Kien CL et al.; To investigate their putative capacity for lactose digestion, primed continuous orogastric infusions of {1-13C}glucose and D-{1-13C}lactose were administered on consecutive days to five premature infants (30-31 wk gestation, 15-32 days of age), who were fed by orogastric infusions of human milk or formula . By monitoring the plateau isotopic enrichment of plasma glucose using isotopomers containing the entire derivatized glucose molecule or C-2 through C-6, we were able to distinguish label appearing in the peripheral circulation deriving from unmetabolized glucose from that arising from recycled or fermented glucose (or lactose) . Isotopic enrichment of the C-1 of glucose, corrected for recycling, was then calculated during each tracer infusion, and the fraction of dietary lactose subjected to in vivo hydrolysis was estimated from these values and the respective tracer infusion rates, assuming similar absorptive and metabolic fates of labeled glucose arising from either tracer . This fraction averaged 1.02 +/- 0.16 (SD), suggesting that lactose digestion is efficient by 34-wk postconceptional age.

Am J Gastroenterol, 1992 Nov, 87(11), 1629 - 30
Dysgonic fermenter-3: a bacterium associated with diarrhea in immunocompromised hosts; Heiner AM et al.; We describe two patients with chronic diarrhea associated with dysgonic fermenter-3 (DF-3) infection . One patient had common variable hypogammaglobulinemia and the other hand chronic idiopathic neutropenia and human immunodeficiency virus infection . Specific stool culture techniques were necessary to isolate DF-3 . The organism was sensitive to clindamycin, tetracycline, and trimethoprim-sulfamethoxazole . Antibiotic therapy eradicated the organism and the diarrhea resolved in both patients . DF-3 is a little-recognized organism associated with diarrhea in the immunocompromised patient . It should be suspected when routine evaluation and stool cultures are not diagnostic.

Proc Natl Acad Sci U S A, 1992 Nov 1, 89(21), 10188 - 92
Cloning and expression of an NADP(+)-dependent alcohol dehydrogenase gene of Entamoeba histolytica; Kumar A et al.; Ethanol is the major metabolic product of glucose fermentation by the protozoan parasite Entamoeba histolytica under the anaerobic conditions found in the lumen of the colon . Here an internal peptide sequence determined from a major 39-kDa amoeba protein isolated by isoelectric focusing followed by SDS/PAGE was used to clone the gene for the E . histolytica NADP(+)-dependent alcohol dehydrogenase (EhADH1; EC 1.1.1.2) . The EhADH1 clone had an open reading frame that was 360 amino acids long and encoded a protein of approximately 39 kDa (calculated size) . EhADH1 showed a 62% amino acid identity with the tetrameric NADP(+)-dependent alcohol dehydrogenase of Thermoanaerobium brockii . In contrast, EhADH1 showed a 15% amino acid identity with the closest human alcohol dehydrogenase . EhADH1 contained 18 of the 22 amino acids conserved in other alcohol dehydrogenases, including glycines involved in binding NAD(P)+ as well as histidine and cysteine residues involved in binding the catalytic zinc ion . Like the T . brockii alcohol dehydrogenase, EhADH1 lacked a 23-amino acid stretch present in other alcohol dehydrogenases that includes four cysteines that bind a second noncatalytic zinc ion . An EhADH1-glutathione-S-transferase fusion protein showed the expected NADP(+)-dependent alcohol dehydrogenase and NADPH-dependent acetaldehyde reductase activities . The enzymatic activities of the EhADH1 fusion protein were inhibited by pyrazole and 4-methylpyrazole.

J Nutr, 1992 Nov, 122(11), 2226 - 32
Endogenous allantoin excretion in response to changes in protein supply in sheep; Chen XB et al.; Endogenous allantoin derives from the breakdown of tissue nucleic acids . This study examined the effect of changes in protein supply on endogenous allantoin excretion by sheep . The animals were nourished by infusions of volatile fatty acids into the rumen and casein into the abomasum, thus avoiding ruminal microbial fermentation (i.e., no supply of exogenous nucleic acids) . While a constant energy supply was maintained, the protein supply was altered in one of two ways: 1) changed from 0 to 3000 mg casein-N/kg metabolic weight (W0.75) per day in progressive steps; or 2) completely removed from an initial constant level {500 mg N/(kg W0.75.d)} . With the first alteration, endogenous allantoin excretion was not directly affected by the daily N input or N retention, but was linearly correlated with the cumulative N retention . With the second alteration, allantoin excretion increased (35-145%) on the first day after removal of the protein supply and then fell to a level equivalent to, or lower than, that before protein removal . The results suggest that the changes in endogenous allantoin excretion may reflect remodeling of the metabolic state of the animal during periods when protein supply fluctuates.

FEMS Microbiol Lett, 1992 Nov 1, 77(1-3), 123 - 7
L-lysine repression of penicillin biosynthesis and the expression of penicillin biosynthesis genes acvA and ipnA in Aspergillus nidulans; Brakhage AA et al.; The addition of 0.1 M L-lysine to the fermentation medium reduced the production of penicillin by about 50% in Aspergillus nidulans . To analyse this effect at the molecular level, the expression of the penicillin biosynthesis genes acvA and ipnA, encoding delta-(L-alpha-aminoadipyl)-L-cysteinyl-D-valine synthetase and isopenicillin N synthetase, was studied by using translational fusions with different reporter genes (strain AXB4A, acvA-uidA, ipnA-lacZ fusions; AXB4B, acvA-lacZ, ipnA-uidA fusions) integrated in single copy at the chromosomal argB locus of Aspergillus nidulans . Irrespective of the reporter genes used the expression of acvA and ipnA fusion genes was repressed in L-lysine grown cultures . The expression of a fusion gene of an A . nidulans primary metabolism gene (oliC-lacZ) was not affected by L-lysine.

Appl Microbiol Biotechnol, 1992 Nov, 38(2), 152 - 7
Transformation of vitamin D3 to 1 alpha,25-dihydroxyvitamin D3 via 25-hydroxyvitamin D3 using Amycolata sp . strains; Sasaki J et al.; To enzymatically synthesize active metabolites of vitamin D3, we screened about 500 bacterial strains and 450 fungal strains, of which 12 strains were able to convert vitamin D3 to 1 alpha,25-dihydroxyvitamin D3 {1 alpha,25(OH)2D3} via 25-hydroxyvitamin D3 {25(OH)D3} . The conversion activity was only detected in strains belonging to the genus Amycolata among all the organisms tested . A preparative-scale conversion of vitamin D3 to 25(OH)D3 and 1 alpha,25(OH)2D3 in a 200-1 tank fermentor using A . autotrophica FERM BP-1573 was accomplished, yielding 8.3 mg 25(OH)D3/l culture and 0.17 mg 1 alpha,25(OH)2D3/l culture . A related compound, vitamin D2, could be also converted to 25-hydroxyvitamin D2 and 1 alpha,25-dihydroxyvitamin D2 using the same strain . The cytochrome P-450 of FERM BP-1573 was detected by reduced CO difference spectra in whole-cell suspensions . Vitamin D3 in the culture induced cytochrome P-450 and the conversion activity simultaneously, suggesting that the hydroxylation at C-25 of vitamin D3 and at C-1 of 25(OH)D3 originates from cytochrome P-450.

Appl Microbiol Biotechnol, 1992 Nov, 38(2), 158 - 64
Influence of pH, nitrogen and phosphorus sources on the production of hepatitis B virus pre-S2 antigen by Hansenula polymorpha; de Roubin MR et al.; Experimental design techniques were used to study the influence of the composition of the culture medium on the production of hepatitis B virus pre-S2 antigen by the methylotrophic yeast Hansenula polymorpha . pH, phosphoric acid, ammonium chloride and yeast extract concentrations were selected as experimental factors and their influence was investigated using Central Composite design techniques . The results indicated that antigen yield was maximized at high pH and in a culture medium containing both ammonium chloride and yeast extract . Phosphoric acid was found to have a detrimental effect on antigen production . This study allowed a 50% increase in antigen production in a medium in which the yeast extract concentration was decreased to 32 g/l . These optimal conditions have been confirmed with an octagonal design experiment . Moreover, it was shown that the antigen produced was very stable up to at least 8 days after induction and that the yeast extract concentration could be lowered to 22 g/l without appreciable effect on antigen yield . The increase in antigen production was not due to an increase in cell biomass, since no correlation could be found between these two parameters . The newly defined culture medium should allow a greatly increased antigen production at the fermentor level, at a lower cost and with minimal operational problems.

Appl Microbiol Biotechnol, 1992 Nov, 38(2), 139 - 40
Safe biotechnology (4) . Recommendations for safety levels for biotechnological operations with microorganisms that cause diseases in plants; Frommer W et al.; The Working Party on Safety in Biotechnology of the European Federation of Biotechnology has proposed a classification of microorganisms that cause diseases in plants . In this paper appropriate safety levels are proposed for these classes of microorganisms in order to ensure that research, development and industrial fermentation work with plant pathogens will limit the risk of outbreaks of diseases in crops that could result from work with such microorganisms when they are cultivated in laboratories, glasshouses and biotechnology installations.

J Ind Microbiol, 1992 Nov, 11(1), 7 - 12
Improved processes for the production and isolation of dynemicin A and large-scale fermentation in a 10,000-liter fermentor; Lam KS et al.; Supplementing the culture of Micromonospora chersina sp . nov . No . M956-1 with NaI (0.5 mg/l) enhanced the production of dynemicin A by 35-fold in shake flask culture . Homogeneous dynemicin A was obtained from the whole broth extract by Dicalite chromatography, Sephadex LH-20 chromatography and vacuum liquid chromatography . Gram quantities of dynemicin A were obtained from the fermentation of M . chersina sp . nov . No . M956-1 in a 10,000-liter fermentor.

Comp Biochem Physiol Comp Physiol, 1992 Nov, 103(3), 601 - 4
Comparison of fibre digestion and digesta retention time between nutrias (Myocaster coypus) and guinea-pigs (Cavia porcellus); Sakaguchi E et al.; 1 . Digestibilities of feed, and transit and retention time of fluid and particle digesta marker measured in nutrias (Myocaster coypus) and guinea-pigs (Cavia porcellus) fed on a diet containing 50% alfalfa . 2 . The digestibility of fibre was higher in the nutria, along with the longer retention time of digesta . 3 . The liquid and particle marker were similarly excreted, suggesting no separation mechanism in the gastrointestinal tract of both the animals . 4 . The apparent digestibility of protein in the nutria was superior to the guinea-pig and other small hindgut fermenters, suggesting that the contribution of coprophagy on protein nutrition of nutrias is significant.

Zhonghua Min Guo Wei Sheng Wu Ji Mian Yi Xue Za Zhi, 1992 Nov, 25(4), 209 - 22
Isolation of astaxanthin over-producing mutants of Phaffia rhodozyma and their fermentation kinetics; Fang TJ et al.; Phaffia rodozyma CCRC-21346, CBS-6938, and CBS-5908 were treated with mutagenic agent NTG (N-methyl-N'-nitro-N-nitrosoguanidine) several times, then they were plated onto yeast-malt agar containing beta-ionone as a selective medium . Several isolates had increased astaxanthin content compared with the parental natural isolates . NCHU-FS301, one of the NTG treated strains, produced considerably more astaxanthin (1515.63 micrograms/g yeast) than the parent CBS-6938 (565.08 micrograms/g yeast) . In studying the effects of carbon sources on the red pigment formation, it was found that glucose supported the highest total astaxanthin production (7809.3 micrograms/l) . Yeast extract was the best nitrogen source in supporting the highest total astaxanthin formation (8637.5 micrograms/l) . Beef extract, yeast extract, and potassium nitrate added in an equal ratio as a nitrogen source supported more pigment formation (8052.6 micrograms/l) than the rest of the mixture tested . Using kinetic parameters of specific growth rate (mu) and specific astaxanthin productivity (qp) to judge the association between growth behavior and product formation, the NCHU-FS301 showed more positive growth-associated fermentation type than the parent strain . These astaxanthin-overproducing mutants could be useful for the aquacultural industry in providing a natural source of astaxanthin.

FEMS Microbiol Lett, 1992 Nov 1, 77(1-3), 261 - 7
Oscillatory metabolism of Saccharomyces cerevisiae in continuous culture; Satroutdinov AD et al.; Short-period (40-50 min) synchronized metabolic oscillation was found in a continuous culture of yeast Saccharomyces cerevisiae under aerobic conditions at low-dilution rates . During oscillation, many parameters changed cyclically, such as dissolved oxygen concentration, respiration rate, ethanol and acetate concentrations in the culture, glycogen, ATP, NADH, pyruvate and acetate concentrations in the cells . These changes were considered to be associated with glycogen metabolism . When glycogen was degraded, the respiro-fermentative phase was observed, in which ethanol was produced and the respiration rate decreased . In this phase, the levels of intracellular pyruvate and acetate became minimum, ATP became high and intracellular pH at its lowest level . When glycogen metabolism changed from degradation to accumulation, the respiratory phase started, during which ethanol was re-assimilated from the culture and the respiration rate increased . Intracellular pyruvate and acetate became maximum, ATP decreased and the intracellular pH appeared high . These findings may indicate new aspects of the control mechanism of glycogen metabolism and how respiration and ethanol fermentation are regulated together under aerobic conditions.

J Nutr, 1992 Nov, 122(11), 2257 - 72
Simulation of nutrient digestion, absorption and outflow in the rumen: model evaluation; Neal HD et al.; A mathematical model of the rumen fermentation processes constructed to predict nutrient supply to the host animal was evaluated . Sensitivity analysis on high fiber, starch and protein diets indicated that the model responds appropriately to these types of diets and to changes in parameter values, and revealed that the model is sensitive to the availability of hexose for non-growth microbial processes and to the maximum storage rate of polysaccharides in amylolytic microbes, although sensitivity varied with diet composition . Of the parameters whose values were dependent on diet, the fraction of protozoa in the amylolytic microbial pool and the fluid and solid passage rates needed the most careful estimation . When model predictions of nutrient supply were compared with the experimental observations, those for duodenal flows of neutral detergent fiber, total non-ammonia nitrogen (NAN) and total volatile fatty acid rumen concentration were satisfactory for several feeding strategies . The partition of NAN flow into microbial and non-microbial NAN flow and the molar proportions of volatile fatty acid production and concentration were not predicted well . The representation of the complex interactions between rumen microbial populations and of their effects on the production of specific volatile fatty acids merits further study for an improvement in the prediction of nutrient supply.

J Nutr, 1992 Nov, 122(11), 2239 - 56
Simulation of nutrient digestion, absorption and outflow in the rumen: model description; Dijkstra J et al.; A mathematical model is described that stimulates the digestion, absorption and outflow of nutrients in the rumen . The model consists of 17 state variables, representing nitrogen, carbohydrate, lipid, microbial and volatile fatty acid pools . The flux equations are described by Michaelis-Menten or mass action forms with parameters calculated from the literature . Several specific areas of improvement in representation of rumen processes were reconsidered during model development . These included microbial substrate preference, differential outflow and chemical composition of rumen microbes, recycling of microbial matter within the rumen, uncoupling of fermentation with respect to nitrogen availability, reduced microbial activity at reduced rumen pH and pH-dependent absorption of volatile fatty acids and ammonia . The model was used to examine the effects of the diet on the profile of nutrients available for absorption and was shown to respond appropriately to different intake and nitrogen levels . The validity of the improvements and the predictions of nutrient supply on a variety of dietary inputs are tested in a companion paper.

Med Anthropol, 1992 Nov, 15(1), 41 - 62
Symbolic mediation and commoditization: a critical examination of alcohol use among the Haya of Bukoba, Tanzania; Carlson RG; Low-alcohol-content fermented beverages are thoroughly enmeshed in the social, economic, commensal, and cosmological spheres of life among most peoples of sub-Saharan Africa . This paper describes and analyzes the role of alcoholic beverages as symbolic mediators and commodities among the Haya of northwest Tanzania . Data gathered during field research in 1985-86 are employed to describe the ways in which the Haya portray excessive drinking and the indigenous strategies they use to address frequent drunkenness when it is perceived as a health problem . A central feature of the paper contrasts the role of a cultural schema of four levels of intoxication in processes of symbolic mediation and commoditization, thereby contributing to critical medical anthropological analysis.

Antonie Van Leeuwenhoek, 1992 Nov, 62(4), 273 - 83
Evaluation of two unstructured mathematical models for the penicillin G fed-batch fermentation; Nicolai BM et al.; The mathematical model for the penicillin G fed-batch fermentation proposed by Heijnen et al . (1979) is compared with the model of Bajpai & Reuss (1980) . Although the general structure of these models is similar, the difference in metabolic assumptions and specific growth and production kinetics results in a completely different behaviour towards product optimization . A detailed analysis of both models reveals some physical and biochemical shortcomings . It is shown that it is impossible to make a reliable estimation of the model parameters, only using experimental data of simple constant glucose feed rate fermentations with low initial substrate amount . However, it is demonstrated that some model parameters might be key factors in concluding whether or not altering the substrate feeding strategy has an important influence on the final amount of product . It is illustrated that feeding strategy optimization studies can be a tool in designing experiments for parameter estimation purposes.

Eur J Biochem, 1992 Oct 15, 209(2), 603 - 11
Substrate specificity and properties of the aryl-alcohol oxidase from the ligninolytic fungus Pleurotus eryngii; Guillen F et al.; The production in a 5-1 fermenter of the extracellular enzymes laccase and aryl-alcohol oxidase by the fungus Pleurotus eryngii was studied . The latter enzyme has been purified 50-fold by Sephacryl S-200 and Mono Q chromatography . Purified aryl-alcohol oxidase is a unique flavoprotein with 15% carbohydrate content, a molecular mass of 72.6 kDa (SDS/PAGE) and a pI of 3.9 . The enzyme presents wide specificity, showing activity on benzyl, cinnamyl, naphthyl and aliphatic unsaturated alcohols . Neither activity nor inhibition of veratryl alcohol oxidation was found with saturated alcohols, but competitive inhibition was produced by aromatic compounds which were not aryl-alcohol oxidase substrates, such as phenol or 3-phenyl-1-propanol . From these results, it was apparent that a double bond conjugated with a primary alcohol is necessary for substrate recognition by aryl-alcohol oxidase, and that activity is increased by the presence of additional conjugated double bonds and electron donor groups . Both affinity and maximal velocity during enzymic oxidation of methoxybenzyl alcohols were affected in a similar way by ring substituents, increasing from benzyl alcohol (Km = 0.84 mM, Vmax = 52 U/mg) to 4-methoxybenzyl alcohol (Km = 0.04 mM, Vmax = 208 U/mg) . Aryl-alcohol oxidase presents also a low oxidase activity with aromatic aldehydes, but the highest activity was found in the presence of electron-withdrawing groups.

Int J Sports Med, 1992 Oct, 13 Suppl 1, S89 - 91
Muscle enzymatic composition and metabolic regulation in high altitude adapted natives; Hochachka PW; Quechuas and Sherpas have long attracted the interest of high altitude biology and medicine . From our current knowledge, it appears that three of their most impressive high altitude adaptations are (i) high efficiency performance even in hypobaric hypoxia, (ii) low maximum (aerobic and anaerobic) capacities, and (iii) high endurance (the latter being less well documented, but widely accepted) . Muscle biopsy and enzyme activity measurements clarify the basis for at least some of these adaptations . Firstly, low activity levels of enzymes in oxidative metabolism (comparable to power athletes) predict low VO2max capacities, as previously observed . Secondly, anaerobic glycolytic capacities also are low (comparable to endurance athletes) which explains low anaerobic work capacities . Thirdly, the glycolytic pathway is seemingly organized for carbohydrate oxidation, not fermentation . Because glucose (glycogen) metabolism uses O2 efficiently, the endurance characteristic may arise from coupling carbohydrate-based adenosine triphosphate (ATP) synthesis with efficient pathways of ATP utilization (for high yield of muscle work/ATP).

J Gen Microbiol, 1992 Oct, 138 ( Pt 10), 2235 - 41
Characterization of an anaerobic fungus from llama faeces; Marvin-Sikkema FD et al.; An anaerobic fungus was isolated from llama faeces . Based on its morphological characteristics, polyflagellated zoospores, extensive rhizoid system and the formation of monocentric colonies, the fungus is assigned to the genus Neocallimastix . Neocallimastix sp . L2 is able to grow on several poly-, oligo- and monosaccharides . It differs from other Neocallimastix isolates in its inability to ferment inulin . Neocallimastix sp . L2 requires CO2 for growth . In the presence of 100% CO2 in the gas phase glucose is fermented to H2, CO2, formate, acetate, lactate, succinate and ethanol (33.8, 15.4, 74.3, 69.2, 26.7, 8.2, and 28.7 mmol per 100 mmol glucose, respectively) . Reduced sulphur compounds can be used as sulphur source and ammonium or amino acids as nitrogen source . The temperature range for glucose fermentation is from 37 to 42 degrees C with an optimum of around 38 degrees C . The pH range for glucose fermentation is from pH 6 to pH 8 with a broad optimum between pH 6.5 and pH 7.5 . The zoospores of Neocallimastix sp . L2 contain ribosomal 'globules' and hydrogenosomes . In the kinetosomes of the zoospores spurs, scoops and skirts are visible . In both the rhizoids and the sporangia 'crystal bodies' and hydrogenosomes are present . Mitochondria were not detected in either of these life stages.

J Gen Microbiol, 1992 Oct, 138 ( Pt 10), 2101 - 12
Isolation and characterization of Escherichia coli mutants affected in aerobic respiration: the cloning and nucleotide sequence of ubiG . Identification of an S-adenosylmethionine-binding motif in protein, RNA, and small-molecule methyltransferases; Wu G et al.; We report the isolation and characterization of a mutant of Escherichia coli unable to grow aerobically on non-fermentable substrates, except for very slow growth on glycerol . The mutant contains cytochrome oxidases o and d, and grows anaerobically with alternative electron acceptors . Oxygen consumption rates of cell-free extracts were low relative to activities in an isogenic control strain, but were restored in vitro by adding ubiquinone-1 to cell-free extracts . Transformation with a cloned 2.8 kb ClaI-EcoRV fragment of chromosomal DNA restored the ability of this mutant (AN2571) to grow on succinate and also restored cellular quinone levels in this strain . The plasmid also complemented a previously isolated ubiG mutant (AN151) for aerobic growth on succinate . The nucleotide sequence revealed a 0.7 kb portion of gyrA . Unidirectional nested deletions from this fragment and complementation analysis identified an open reading frame encoding a protein with a predicted molecular mass of 26.5 kDa . This gene (ubiG) encodes the enzyme 2-octaprenyl-3-methyl-5-hydroxy-6-methoxy-1,4-benzoquinone methyltransferase, which catalyses the terminal step in the biosynthesis of ubiquinone . The open reading frame is preceded by a putative Shine-Dalgarno sequence and followed by three palindromic unit sequences . Comparison of the inferred amino acid sequence of UbiG with the sequence of other S-adenosylmethionine (AdoMet)-dependent methyltransferases reveals a highly conserved AdoMet-binding region . The cloned 2.8 kb fragment also contains a sequence encoding the C-terminus of a protein with 42-44% identity to fungal acetyl-CoA synthetases.

J Antibiot (Tokyo), 1992 Oct, 45(10), 1599 - 608
A new anthracycline antibiotic, cinerubin R . Taxonomy, structural elucidation and biological activity; Nakata M et al.; A novel anthracycline antibiotic, cinerubin R, was isolated from the fermentation broth of Streptomyces eurythermus strain H1715MY2 . The structure of cinerubin R was elucidated to be 4"-aculosyl-4'-rhodinosyl-7-rhodosaminyl-epsilon-py rromycinone . Cinerubin R was active against Gram-positive bacteria and inhibited the growth of divergent multi-drug-resistant cells to the same extent as their parental cells.

Vet Microbiol, 1992 Oct, 32(3-4), 375 - 90
Application of dot immunobinding on membrane filtration (MF dot) to the study of relationships within "M . mycoides cluster" and within "glucose and arginine-negative cluster" of ruminant mycoplasmas; Poumarat F et al.; A total of 189 isolates from cattle, sheep and goats, allocated to two groups on biochemical grounds, have been examined by a dot immunobinding membrane-filtration (MF dot) method . Seventy glucose fermenting isolates, showing relationships with the "Mycoplasma mycoides cluster", have been compared by MF dot against polyclonal hyperimmunesera prepared against the following reference strains: M . mycoides subsp . mycoides, small colony type (SC), strain PG1 and large colony type (LC) strain Y Goat; M . capricolum strain California Kid (CK); M . species bovine serogroup 7 strain PG50, and, ovine/caprine serogroup 11 strain 2-D . The isolates fell into 5 main groups: (a) 14 serologically homogeneous isolates similar to subsp . mycoides SC PG1 (b) 4 homogeneous isolates similar to PG50 (c) 14 isolates all serologically similar to Y Goat, but heterogeneously reactive with subsp . capri PG3 and M . capricolum CK antisera (d) 7 isolates serologically similar to subsp . capri PG3, but heterogeneously reactive with subsp . mycoides SC PG1, M . capricolum CK and 2-D antisera (e) 28 isolates strongly reactive with both M . capricolum CK and serogroup 7 PG50 antisera . 119 isolates that were all glucose and arginine negative were also compared by the MF dot method with the reference strains . Most of these could be classified definitely as M . bovis (78 isolates), M . agalactiae (21 isolates) and serogroup 11 (5 isolates) . 13 isolates gave a strong reaction with both M . bovigenitalium and serogroup p11 antisera . 2 isolates showed an unclassifiable pattern . The results confirm that the glucose and arginine-negative cluster strains that reacted with 2-D antiserum, also share serological relationships with the "M . mycoides cluster", albeit with a very heterogeneous pattern.

Scand J Gastroenterol, 1992 Oct, 27(10), 819 - 28
Fructose and related food carbohydrates . Sources, intake, absorption, and clinical implications; Rumessen JJ; It is possible to point out subjects consuming considerable quantities of fructose and sorbitol, and the intake seems to be increasing both from added and natural sources . Studies of the absorption of fructose in animals are inconsistent, and the mechanisms of fructose uptake seem to vary in accordance with the species . In most species fructose absorption takes place by a specific carrier (facilitated transport), but it may be active in the rat . In vitro studies of human intestine are very scarce; there is no evidence of active intestinal fructose transport in the human intestine . By means of hydrogen breath tests, a very low absorption capacity for fructose given as the free monosaccharide has been found in humans . Fructose given as sucrose or in equimolar combinations with glucose is well absorbed, and only fructose in excess of glucose is malabsorbed . On this basis it is hypothesized that two different uptake mechanisms for fructose are present in the human intestine . One of these may be a disaccharidase-related uptake system . Sorbitol ingestion may aggravate malabsorption of fructose given as the monosaccharide; it is not known whether a specific mechanism is involved . In children and adults with functional bowel distress the absorption capacities for fructose may not differ from those of healthy individuals, but malabsorption of fructose and/or sorbitol may be the cause of or aggravate abdominal symptoms . Fructose polymers (fructans) are also subject to increasing nutritional interest . Fructans are not absorbed in the small intestine but are strongly fermented in the large bowel . Fructans may be of potential benefit for large-bowel function and blood glucose regulation.

Plant Foods Hum Nutr, 1992 Oct, 42(4), 351 - 8
Preparation nutritional value and acceptability of barley rabadi--an indigenous fermented food of India; Gupta M et al.; Rabadi fermentation of barley flour-buttermilk mixture (fresh and autoclaved) at 30, 35 and 40 degrees C for 6, 12, 18, 24 and 48 h lowered pH, enhanced titratable acidity and did not change fat and total mineral (Ca, Fe, Cu, Zn, Mn and P) content . Protein content of fermented fresh as well as autoclaved barley flour-buttermilk mixture either decreased or remained unchanges . Rabadi prepared from both types of barley flour at different temperatures and time periods was acceptable; but that which was fermented at 40 degrees C for 48 h was less acceptable in terms of taste.

J Dairy Sci, 1992 Oct, 75(10), 2769 - 75
Evaluation of pearl millet and field peas plus triticale silages for midlactation dairy cows; Messman MA et al.; A mixture of field peas and triticale was planted in spring, harvested as silage, and followed by a double crop of pearl millet, which also was harvested as silage . Eighteen Holstein cows were fed diets based on pea with triticale, pearl millet, or alfalfa plus corn silages . Dry matter digestibility of the pea with triticale diet was higher than for control (71.1 vs . 66.9%), but DM digestibility was not different between control and pearl millet diets . Milk production was not affected by diets containing pea with triticale or pearl millet compared with control diets (25.2, 23.2, and 24.5 kg/d) . Cows fed pea with triticale produced milk with a higher concentration of fat (4.59 vs . 3.35%) and more FCM (27.3 vs . 22.1 kg/d) than those fed the control diet . However, cows fed the control diet gained more BW than those receiving pea with triticale or pearl millet diets . Partitioning of energy between body stores and milk production was different between cows fed pea with triticale and control diets; however, total energy use was not different (32.4 vs . 30.5 Mcal of NE(L)/d) . Differences in energy partitioning may have been caused partly by differences in ruminal fermentation of the respective diets.

J Anim Sci, 1992 Oct, 70(10), 2950 - 8
Performance of feedlot steers fed diets containing laidlomycin propionate or monensin plus tylosin, and effects of laidlomycin propionate concentration on intake patterns and ruminal fermentation in beef steers during adaptation to a high-concentrate diet; Galyean ML et al.; Two hundred eighty-eight beef steers (British x Continental x Brahman) were fed a 90% concentrate diet containing either no ionophore (control), laidlomycin propionate at either 6 or 12 mg/kg of dietary DM, or monensin plus tylosin (31 and 12 mg/kg of DM, respectively) . Neither of the two levels of laidlomycin propionate nor monensin plus tylosin affected (P greater than .10) ADG or feed:gain ratio . Monensin plus tylosin reduced (P less than .01) daily DMI for the 161-d trial period compared with the other three treatments . Laidlomycin propionate at 6 mg/kg increased (P less than .05) DMI relative to the control, laidlomycin propionate at 12 mg/kg, and monensin plus tylosin diets during the 2nd wk of the trial and from d 57 to 84 . Treatments did not affect carcass measurements . In a second experiment, 12 ruminally cannulated steers were fed diets containing no ionophore or laidlomycin propionate at either 6 or 12 mg/kg of DM . Samples were obtained for two consecutive days while the dietary concentrate level was 75%, after which the diet was switched abruptly to 90% concentrate, and samples were collected on several days during a 21-d period . The rate at which steers consumed their daily allotment of feed was not altered markedly by laidlomycin propionate . Likewise, laidlomycin propionate did not affect total ruminal VFA concentrations or proportions . Ruminal concentrations of D-lactate were reduced (P less than .10) by 6 but not by 12 mg/kg of laidlomycin propionate.(ABSTRACT TRUNCATED AT 250 WORDS)

FEMS Microbiol Lett, 1992 Oct 1, 76(1-2), 13 - 7
Characterization of killer-resistant strains of Saccharomyces cerevisiae isolated from spontaneous fermentations; Cansado J et al.; A study of 26 killer-resistant wine strains of Saccharomyces cerevisiae, isolated during spontaneous fermentations in three vineyards in NW Spain, was carried out employing several methods that included a spheroplast-killing assay and analysis of chromosomal DNA patterns by pulse-field agarose electrophoresis . The results showed that 92% of the strains were derivatives of K2 killer toxin producing wine strains isolated from the same fermentations, and that they could be grouped into four different karyotypes . The remaining strains were killer-resistant at cell-wall level and were not related to the others, as was demonstrated by the absence of L and M ds-RNAs and by their different karyotypes.

Gastroenterology, 1992 Oct, 103(4), 1167 - 73
Scintigraphic demonstration of lactulose-induced accelerated proximal colon transit; Barrow L et al.; Although lactulose, a widely used cathartic, is known to increase stool frequency, details of its site of action in the colon are obscure . In the present study a noninvasive scintigraphic technique was used to closely follow the movements of proximal colonic contents . Lactulose, 10-20 mL three times daily, significantly accelerated mean transit through the ascending colon from 12.9 +/- 3.7 to 7.0 +/- 2.5 hours (n = 11; P less than 0.01) . This was associated with the occurrence of mass movements, with six such events seen during lactulose treatment whereas only one was seen during the control study (P less than 0.05) . Lactulose also accelerated movement through the rest of the colon so that at 24 hours after dosing the geometric center of the isotope bolus was distal to that seen during the control study (6.6 +/- 1.2 vs . 4.7 +/- 1.3; n = 11, P less than 0.001) . This model of diarrhea in otherwise normal subjects was subsequently used to study the effects of viscous gels in diarrhea . The viscous and relatively poorly fermented gel ispaghula, 3.5 g three times daily, abolished mass movements and was associated with a small but significant increase in proximal colonic transit time, which increased from 6.1 +/- 2.1 to 7.7 +/- 1.5 hours (n = 8; P less than 0.05) . By contrast, the viscous but readily fermentable gelling agent guar gum, 5 g three times daily, further accelerated the cathartic effect of lactulose, with the mean transit time decreasing from 6.4 +/- 2.3 to 4.7 +/- 1.7 hours (n = 8; P less than 0.05) . The acceleration of proximal colonic transit by lactulose may be a useful model to study diarrhea and its modification by therapy.

FASEB J, 1992 Oct, 6(13), 3153 - 61
Aerobic fermentation of glucose by trypanosomatids; Cazzulo JJ; The consumption of glucose by trypanosomatid protozoa such as Trypanosoma brucei, Trypanosoma cruzi, Leishmania spp., and Crithidia spp . is characterized by the excretion of reduced products such as succinate, pyruvate, ethanol, L-alanine, or lactate (depending on the species) not only in anaerobiosis, but also under aerobic conditions . The "aerobic fermentation" of glucose is accompanied by a complete lack, or even a reversal, of the Pasteur effect . This peculiar catabolism is mediated by a so-far unique compartmentation of the glycolytic enzymes, most of which are placed in an organelle called the glycosome; by an almost complete lack of inhibitory controls at the level of hexokinase and phosphofructokinase; and by a central role of CO2 fixation through the reaction catalyzed by phosphoenolpyruvate carboxykinase . The production of fermentative products seems to be due to a relative inefficiency of the respiratory chain, which lacks NADH dehydrogenase and the first phosphorylation site and preferentially uses succinate as substrate.

Int J Syst Bacteriol, 1992 Oct, 42(4), 542 - 6
Biochemical and chemical studies on strains designated Prevotella intermedia and proposal of a new pigmented species, Prevotella nigrescens sp . nov; Shah HN et al.; A total of 31 strains of Prevotella intermedia were subjected to DNA-DNA hybridization and were characterized by performing physiological tests and by performing a multilocus enzyme analysis, using malate dehydrogenase and glutamate dehydrogenase . All of the strains assigned to P . intermedia fermented glucose and sucrose, hydrolyzed starch but not esculin, and produced indole, acetic, isobutyric, isovaleric, and succinic acids as metabolic end products . The results of DNA reassociation experiments performed with the reference probe permitted separation of the strains into two well-defined homology groups . In addition, strains with DNAs that hybridized with DNA from strain ATCC 25611T (T = type strain) had high levels of peptidase activity and cleaved lipid substrates (4-methylumbelliferyl laurate and 4-methylumbellifelyl elaidate) . Multilocus enzyme electrophoresis revealed two electromorphic profiles, one characteristic of strain ATCC 25611T and the other characteristic of strain ATCC 33563T . We propose that a new species, Prevotella nigrescens, should be created for the genetically distinct group of strains that hybridized with strain ATCC 33563T . Strain ATCC 33563 is designated the type strain of P . nigrescens.

Int J Syst Bacteriol, 1992 Oct, 42(4), 536 - 41
Emended descriptions of Prevotella denticola, Prevotella loescheii, Prevotella veroralis, and Prevotella melaninogenica; Wu CC et al.; During studies of human periodontal disease, a number of bacterial strains were encountered that, on the basis of results of standard biochemical tests, appeared to be Prevotella buccalis, Prevotella denticola, Prevotella melaninogenica, or Prevotella loescheii . However, use of the standard biochemical tests, cellular fatty acid analyses, and the polyacrylamide gel electrophoresis patterns of soluble proteins resulted in conflicting identifications of these strains . The results of tests for cellobiose fermentation, inulin fermentation, and pigment production were responsible for most of the discordant results . Cellular fatty acid analyses in which the Microbial Identification System was used did not differentiate these strains from validly described species, even though separate library entries were created for them . DNA reassociation determinations in which the S1 nuclease procedure was used showed that cellobiose fermentation and pigment production are variable among strains of P . melaninogenica and P . denticola and that fermentation of xylan is not a reliable characteristic for differentiating P . buccalis from Prevotella veroralis . In contrast to previous indications, most strains of P . veroralis do not ferment xylan . These species can be differentiated by DNA-DNA reassociation and by cellular fatty acid analysis, using the Microbial Identification System, but differentiation by currently described phenotypic characteristics is not reliable . Similarly, P . loescheii and the genetically distinct (but closely related) D1C-20 group cannot be distinguished reliably from each other or from P . veroralis, P . denticola, and P . melaninogenica on the basis of currently described phenotypic tests other than cellular fatty acid composition or, for some species, electrophoretic patterns of soluble whole-cell proteins.

Appl Microbiol Biotechnol, 1992 Oct, 38(1), 91 - 3
An expression vector system providing plasmid stability and conditional suicide of plasmid-containing cells; Schweder T et al.; A cloning vector system was constructed on the basis of the pBR322 derivative pEG1 by introducing the whole parB locus of plasmid R1 cloned behind the promoter of the alkaline phosphatase gene (phoA) of Escherichia coli . The parB locus in combination with the phoA promoter ensures both (i) plasmid stabilization due to the post-segregational killing of plasmid-free cells during growth and (ii) killing of the cells induced by the potential environmental signal phosphate limitation . This vector, therefore, appears to be a model system for increasing the stability of recombinant plasmids and for decreasing the potential risks in the application of recombinant bacteria in industrial fermentations.

Appl Microbiol Biotechnol, 1992 Oct, 38(1), 84 - 90
Application of a statistical design to the optimization of culture medium for recombinant interferon-gamma production by Chinese hamster ovary cells; Castro PM et al.; The importance of serum-free medium components on the growth of Chinese hamster ovary (CHO) cells and production of recombinant human interferon(IFN)-gamma was investigated . The complexity of the medium led to the adoption of a statistical optimization approach based on a Plackett-Burman design . From this analysis a set of nutritional components was identified as important for cell growth and recombinant protein production . Glycine was identified as an important determinant of specific growth rate, whereas for cell production bovine serum albumin (BSA), phenylalanine and tyrosine were also identified as important . BSA, sodium pyruvate, glutamate, methionine, proline, histidine, hydroxyproline, tyrosine and phenylalanine were shown to be important for IFN-gamma production . Other medium components, such as insulin, arginine, aspartate and serine produced an inhibitory effect on both cell growth and IFN-gamma production . The effect of the stimulatory nutrients as a whole group was tested by increasing their concentration in the medium . A significant improvement in specific cell growth rate, cell production and IFN-gamma production (up to 45%) was achieved on both shake-flask and fermentor cultures . An increase in the medium concentration of the negative variables had only a small inhibitory effect (approximately 10%) on the same parameters . Analysis of the effects of the group of stimulatory amino acids and BSA on CHO cell growth showed that the effect of the former was independent of BSA.

Trends Biotechnol, 1992 Oct, 10(10), 343 - 8
Image analysis: putting filamentous microorganisms in the picture; Thomas CR; Image analysis can be used to characterize the morphology and simple differentiation of fungi and actinomycetes . It provides a new and powerful tool for the physiologist or fermentation technologist working with filamentous microorganisms.

Appl Environ Microbiol, 1992 Oct, 58(10), 3330 - 6
Determination of fermentable carbohydrate from the upper gastrointestinal tract by using colectomized rats; Monsma DJ et al.; The primary aim of this study was to characterize the carbohydrate that would be supplied to the colon for fermentation under physiological conditions . Colectomized rats were fed fiber-free diets or diets containing 5% (wt/wt) gum arabic . Four (fucose, galactose, glucosamine, and galactosamine) of 11 analyzed sugars accounted for 77% of the total sugar in ileal excreta from colectomized rats fed fiber-free diets . The three sugars in gum arabic, rhamnose, arabinose, and galactose, accounted for 84% of the total sugars in gum arabic ileal excreta . Comparisons of the sugar compositions of the ileal excreta, the water-soluble fractions of the excreta, and three gel filtration fractions of the water-soluble material with those of the water-soluble fraction of rat mucosa, the acetone-soluble fraction of pancreas, and pancreatin suggested that the major source of endogenous carbohydrate is mucin . Gum arabic increased the daily excretion of the four mucin-derived sugars (fucose, galactose, glucosamine, and galactosamine) by the colectomized rats from 473 mumol per day to 634 mumol per day . We conclude that mucin is the major endogenous carbohydrate excreted from the upper gut and that gum arabic increases the amount of this endogenous carbohydrate.

J Dairy Sci, 1992 Oct, 75(10), 2762 - 8
Influence of buffer pH and raw corn starch addition on in vitro fiber digestion kinetics; Grant RJ et al.; The impact was studied of buffer pH (5.8, 6.2, and 6.8) on in vitro digestion kinetics of NDF from alfalfa hay, bromegrass hay, corn silage, and alfalfa and bromegrass hays with raw corn starch added to approximate a ration containing 30% NDF . Ash-free NDF was determined at 0, 6, 12, 18, 24, 30, 36, 48, 72, and 96 h of fermentation . Kinetic parameters were estimated by nonlinear regression using an iteratively reweighted least squares technique . Addition of raw corn starch decreased fiber digestion rate for alfalfa hay and lag for bromegrass hay . Both rate and lag of NDF digestion of all substrates were affected negatively below pH 6.2 . Predicted ruminal NDF digestibilities (as percentage of that at pH 6.8 treatment) declined below pH 6.2 for all forages; addition of starch decreased predicted ruminal NDF digestibility by 23% for both alfalfa and bromegrass hays, even at pH 6.8 . Results suggest that low pH decreases fiber digestion rate and increases lag and that starch accentuates this effect for some substrates.

Eur J Clin Nutr, 1992 Oct, 46 Suppl 2, S77 - 90
Hydrogen and methane breath tests for evaluation of resistant carbohydrates; Rumessen JJ; This review considers in detail the background, principles, techniques, limitations and advantages of the hydrogen and methane breath tests . Resistant food carbohydrates, defined as dietary carbohydrates partly or totally escaping small intestinal assimilation, are fermented in the human colon . This results in production of H2, CH4 and volatile fatty acids . Increased colonic H2 production is a sensitive index of increased carbohydrate fermentation, and a rather constant fraction of the colonic H2 production is excreted by the lungs . It is therefore possible to assess mouth-to-caecum transit times as well as to estimate absorption capacities for several types of resistant carbohydrates by means of H2 breath tests . A prerequisite for correct interpretation is that procedures for determination of H2 concentrations and for breath sampling and storage are carefully validated and standardized . Due to the large interindividual variations of hydrogen excretion, unabsorbable standards should be used . The intraindividual variations of H2 production/excretion and differences in fermentability of different carbohydrate substrates only allow for semiquantitative estimates of malabsorbed amounts of some carbohydrates . Methane breath tests may supplement the information gained from hydrogen measurements, but further evaluations are needed . The hydrogen breath technique is rapid, simple and non-invasive as well as non-radioactive . It may be carried out in a large number of intact individuals under physiological circumstances, and it may be used for studies in children and for field studies . Compared to classical tolerance tests the hydrogen breath test is more sensitive . It is concluded that the hydrogen breath test is a useful tool for investigations of dietary carbohydrates.

Eur J Clin Nutr, 1992 Oct, 46 Suppl 2, S33 - 50
Classification and measurement of nutritionally important starch fractions; Englyst HN et al.; For nutritional purposes, starch in foods may be classified into rapidly digestible starch (RDS), slowly digestible starch (SDS) and resistant starch (RS) . RS may be further divided into three categories according to the reason for resistance to digestion . A method is reported for the measurement of total starch, RDS, SDS, RS and three RS fractions in starchy foods, using controlled enzymic hydrolysis with pancreatin and amyloglucosidase . The released glucose is measured by colorimetry, using a glucose oxidase kit . Values for RDS and SDS in foods obtained by the method reflect the rate of starch digestion in vivo . Values for RS are similar to the amounts of starch escaping digestion in the small intestine of ileostomates, and are a guide to the amounts of starch likely to enter the colon for fermentation . Results are given for a number of starchy foods.

J Am Diet Assoc, 1992 Oct, 92(10), 1239 - 46, 1249
Intestinal fuels: glutamine, short-chain fatty acids, and dietary fiber; Evans MA et al.; In recent years, considerable research has focused on the physiologic effects and clinical uses of three dietary constituents thought to be trophic to the intestinal tract in human beings: glutamine, short-chain fatty acids (SCFAs), and dietary fiber . Glutamine is an important nitrogen-carrying amino acid that may be "conditionally essential" in certain disease states to support the gut barrier and immune function and overall protein use . Colonic irrigations with SCFA preparations have demonstrated enhanced healing of bowel tissue in animals and human beings . Dietary fiber supports bacterial SCFA production, normal stool output, and the gut barrier and immune function . However, optimal fiber doses for various medical conditions are not known, and the risk for gastrointestinal (GI) obstruction, diarrhea, gas, and bloating necessitates careful selection of patients and daily monitoring of fiber tolerance . A review of the current literature indicates that widespread use of glutamine and SCFA additives parenterally and enterally awaits further evidence of safety and efficacy in human beings, establishment of appropriate doses, and advances in formulation technology . Administration of dietary fiber to enhance bowel motility should be considered in long-term tube-fed patients with intact GI function and sufficient fluid tolerance to permit hydration of fiber . Industrywide agreement on fiber analysis methods and labeling standards (eg, fiber fermentability vs solubility) would facilitate selection of enteral products . To streamline studies and optimize research efforts in future clinical trials, standard criteria for evaluating GI function, diarrheagenic factors, and intestinal outcome variables should be established.

Antibiot Khimioter, 1992 Oct, 37(10), 24 - 6
{Effect of inoculum parameters on the specificity of secondary synthesis in cultures producing novobiocin and mycoheptin}; Bezrukova IP et al.; The impact of the vegetative inoculum parameters on specificity of the secondary synthesis in the cultures producing novobiocin and mycoheptin was studied . During the study the fermentation conditions were varied by using the vegetative inoculum differing in the respiration rate after its transfer to the fermentation medium . To show the decisive role of the inoculum parameters in regulation of the specificity of the secondary synthesis, the dynamics of accumulation of certain metabolites forming from glucose along with the main antibiotic and the activity of the key enzymes of the carbohydrate metabolism during the culture growth in the fermentation media were studied . It was found that the specificity of the secondary synthesis with respect to certain metabolites was defined by the intensity of carbohydrate metabolism, i . e . the ratio of the activity of enzymes of glycolysis and the pentosephosphate pathway . In this regard, the inoculum with the maximum respiration rate in an amount of 10 to 20 per cent promoted the highest productivity of the mycelium by the synthesis of novobiocin and mycoheptin while the rate of accumulation of fatty acids, carbohydrates and phenol compounds (for Streptomyces spheroides) and mycopentene (for Streptoverticillium mycoheptinicum) decreased.

Zhongguo Zhong Yao Za Zhi, 1992 Oct, 17(10), 619 - 22, 640
{Anti-inflammatory and analgesic actions of artificial and fermentative Ganoderma sinense (AFGS)}; Wan F et al.; Both AFGS and natural Ganoderma sinense (NGS) have obvious anti-inflammatory and analgesic effects for arthritis in rats induced by carrageenan and the pain reaction in mice induced by hot scalding as well as HAC-induced writhing . AFGS also can reduce the edematous swelling of mice's ears, reduce the capillary permeability of mice skin and obviously inhibit cotton pellets granuloma implanted in rats . It can promote cytophagy capacity of the reticular endothelial cells in mice . No irritation on the gastric mucosa in rats has been observed.

Appl Biochem Biotechnol, 1992 Oct, 37(1), 11 - 7
Protection of Aspergillus niger cellulases by urea during growth on glucose or glycerol supplemented media; Gokhale DV et al.; The cellulase enzymes of Aspergillus niger were found to undergo catabolite repression in the presence of glucose and glycerol accompanied by sudden drop in pH of the fermentation medium below 2.0 . This sudden drop in pH caused inactivation of cellulolytic enzymes produced by Aspergillus niger . The supplementation of nitrogen sources, especially urea, protects A . niger cellulases from inactivation caused by a sudden drop in pH, since urea helped to maintain the pH of the fermentation medium between 3.5 and 4.5 . The role of urea in the protection of cellulase was more prominent when it was used in combination with glycerol (5%).

J Biol Chem, 1992 Sep 15, 267(26), 18298 - 302
Yeast lacking superoxide dismutase . Isolation of genetic suppressors; Liu XF et al.; Null mutants of superoxide dismutase (SOD) in Saccharomyces cerevisiae are associated with a number of biochemical defects . In addition to being hypersensitive to oxygen toxicity, strains containing deletions in both the SOD1 (encoding Cu/Zn-SOD) and SOD2 (encoding Mn-SOD) genes are defective in sporulation, are associated with a high mutation rate, and are unable to biosynthesize lysine and methionine . The sod-linked defect in lysine metabolism was explored in detail and was found to occur at an early step in lysine biosynthesis, evidently at the level of the alpha-amino adipate transaminase . To better understand the role of SOD in cell metabolism, our laboratory has isolated yeast suppressors that have bypassed the SOD defect ("bsd" strains), that is, S . cerevisiae cells lacking SOD, yet resistant to oxygen toxicity . Two nuclear bsd complementation groups have been identified, and both suppress a variety of biological defects associated with sod1 and sod2 null mutants . These results demonstrate that a single gene mutation can alleviate the requirement for SOD in cell growth . Both bsd complementation groups are unable to utilize many non-fermentable carbon sources, suggesting a possible suppressor-linked defect in electron transport.

FEMS Microbiol Lett, 1992 Sep 15, 75(2-3), 213 - 7
Heterotrophic sulfur reduction by Thermotoga sp . strain FjSS3.B1; Janssen PH et al.; Thermotoga sp . strain FjSS3.B1 was able to reduce sulfur to sulfide when grown on a mineral medium with glucose as the sole carbon and energy source . There was no increase in specific growth yield coupled to sulfur reduction, but the specific growth rate, final growth yield, and tolerance of H2 were all increased in the presence of sulfur . At dissolved H2 concentrations, of 550 to 600 mumol/l (at 77 degrees C) growth was not possible unless sulfur was added . Glucose was fermented via the Embden-Meyerhof-Parnas pathway to lactate, acetate, H2 and CO2 (and other unidentified minor products) . The thermodynamic problems associated with the relatively high redox potential electrons from the 1,3-bisphosphoglycerate/glyceraldehyde 3-phosphate couple (E'0 = -350 mV) are overcome by reducing sulfur to sulfide (E'0 = -270 mV) rather than the energetically unfavourable production of H2 (E'0 = -414 mV) . Under high hydrogen partial pressures there was increased production of lactate as an alternative electron sink . The results indicate that sulfur reduction operates primarily as an electron sink rather than as a detoxification reaction or energy-generating mechanism.

Int J Cancer, 1992 Sep 9, 52(2), 286 - 9
Effects of short-chain fatty acids on growth and differentiation of the human colon-cancer cell line HT29; Gamet L et al.; Short-chain fatty acids (SCFAs), namely butyrate, acetate and propionate, originate from the bacterial fermentation of dietary fibers and are the predominant anions present in the large bowel . Our study was carried out to investigate the effects of SCFAs on growth of the human adenocarcinoma cell line, HT29 . The results show that, under our culture conditions, both propionate and butyrate inhibit growth of HT29 cells, whereas acetate has no significant effect . The antiproliferative effect of propionate or butyrate is associated with an inhibition of FCS-induced activation of ornithine decarboxylase (ODC), a key enzyme of polyamine metabolism . Inhibition of growth induced by either propionate or butyrate is not reversed by the addition of putrescine, which reveals that these SCFAs are not acting solely on the ODC/polyamine system . Our data show that propionate and butyrate, unlike acetate, induce an increase in alkaline phosphatase activity, which reflects a more differentiated phenotype than that of untreated control cells . Taken together, our results suggest that propionate, like butyrate, may play an important role in the physiology of the colon and could partially account for the protective effect of dietary fibers with respect to colon carcinogenesis.

J Biol Chem, 1992 Sep 5, 267(25), 18073 - 9
Ultrastructure and pyruvate formate-lyase radical quenching property of the multienzymic AdhE protein of Escherichia coli; Kessler D et al.; The AdhE protein of Escherichia coli is a homopolymer of 96-kDa subunits harboring three Fe(2+)-dependent catalytic functions: acetaldehyde-CoA dehydrogenase, alcohol dehydrogenase, and pyruvate formatelyase (PFL) deactivase . By negative staining electron microscopy, we determined a helical assembly of 20-60 subunits into rods of 45-120 nm in length . The subunit packing is widened along the helix axis when Fe2+ and NAD are present . Chymotrypsin dissects the AdhE polypeptide between Phe762 and Ser763, thereby retaining the alcohol dehydrogenase activity on the NH2-terminal core, but destroying all other activities . PFL deactivation, i.e . quenching of the glycyl radical in PFL by the AdhE protein, was examined with respect to cofactor involvements (Fe2+, NAD, and CoA) . This process is coupled to NAD reduction and requires the intact CoA sulfhydryl group . Pyruvate and NADH are inhibitors that affect the steady-state level of the radical form of PFL in a reconstituted interconversion cycle . Studies of cell cultures found that PFL deactivation in situ is initiated at redox potentials of greater than or equal to +100 mV . Our results provide insights into the structure/function organization of the AdhE multienzyme and give a rationale for how its PFL radical quenching activity may be suppressed in situ to enable effective glucose fermentation.

Curr Genet, 1992 Sep, 22(3), 181 - 9
The UAS(MAL) is a bidirectional promotor element required for the expression of both the MAL61 and MAL62 genes of the Saccharomyces MAL6 locus; Levine J et al.; Maltose fermentation in Saccharomyces yeasts requires one of five unlinked MAL loci: MAL1, 2, 3, 4, or 6 . Each locus consists of three genes encoding maltose permease, maltase and the MAL activator . At MAL6 the genes are called MAL61, MAL62 and MAL63, respectively . Transcription of MAL61 and MAL62 is coordinately induced by maltose and repressed by glucose and this regulation is mediated by the MAL activator . By deletion analysis of the MAL61-MAL62 intergenic region, we show that a 68-basepair region, from base pairs -515 to -582 upstream of the MAL61 start codon, contains a sequence necessary for the maltose-induced expression of MAL61 and MAL62, the UAS(MAL) . This sequence contains two copies of an 11-basepair dyad which may be the active elements of the UAS(MAL) . Using heterologous gene plasmid constructs, we demonstrate that the UAS(MAL) sequence is sufficient for maltose inducibility of MAL62 and that this regulated expression requires a functional MAL activator . Our results suggest that the MAL61-MAL62 intergenic region contains additional distinct elements which function to precisely regulate MAL61 and/or MAL62 expression . Among these are repressing sequences, including a glucose-responsive element located between base pairs -583 and -638, which is partially responsible for mediating glucose-repression of MAL62 expression.

J Bacteriol, 1992 Sep, 174(17), 5526 - 32
GCR3 encodes an acidic protein that is required for expression of glycolytic genes in Saccharomyces cerevisiae; Uemura H et al.; Screening of a mutagenized strain carrying a multicopy ENO1-'lacZ fusion plasmid revealed a new mutation affecting several glycolytic enzyme activities . The recessive single nuclear gene mutation, named gcr3, caused an extremely defective growth phenotype on fermentable carbon sources such as glucose, while growth on respiratory media was almost normal . The GCR3 gene was obtained by growth complementation from a genomic DNA library, and the complemented strains had normal enzyme levels . GCR3 gene was sequenced, and a 99,537-Da protein was predicted . The predicted GCR3 protein was fairly acidic (net charge, -34) . The C-terminal region was highly charged, and an acidic stretch was found in it.

Immunol Lett, 1992 Sep, 34(1), 27 - 30
Mycoplasma fermentans (incognitus strain) induces TNF alpha and IL-1 production by human monocytes and murine macrophages; Gallily R et al.; We have demonstrated that Mycoplasma fermentans (incognitus strain), as well as M . fermentans KL4, PG 18 and IM 1 strains have the ability to activate human peripheral blood monocytes and murine macrophages of two inbred strains to secrete a high level of tumor necrosis factor alpha (TNF alpha) in a dose-dependent manner . Secretion of interleukin-1 (IL-1) was also stimulated following the incubation of human monocytes with the organism . We suggest that cytokine secretion following infection with M . fermentans (incognitus strain) that was detected in AIDS patients may contribute to the pathological manifestations, including cachexia, in this disease.

Shi Yan Sheng Wu Xue Bao, 1992 Sep, 25(3), 283 - 8
{Synthesis cloning and expressions in E coli of human insulin A and B chain genes}; Guo LH et al.; Human insulin A and B chain genes were designed and synthesized by using a rapid and simple method . The synthesized A and B chain genes were cloned separately . The expression (plasmids) pWR 590-HIA and pWR 590-HIB were constructed, and the two plasmids can direct the synthesis of the approximately 590 amino acid-long truncated beta-galactosidases fused to human insulin A or B chains . The fused A or B chain proteins were isolated from the fermented cells and cleaved with BrCN . The resulting mixtures were sulfonated and the sulfonated A and B chains were purified . Human insulin was obtained by using an A and B chain combination method.

J Periodontol, 1992 Sep, 63(9), 768 - 75
Salivary and metabolic factors involved in oral malodor formation; Kleinberg I et al.; Saliva plays a central role in the formation of oral malodor . Such formation has as its basis bacterial putrefaction, the degradation of proteins, and the resulting amino acids by microorganisms . Saliva provides substrates that are readily oxidized and in the process facilitates oxygen depletion . This favors the reduced conditions conducive to production of odoriferous volatiles . At the same time, saliva is a major source of oxygen for the oral bacteria which generally is inhibitory of their formation . The pH is also critical to malodor development; acidity inhibits, whereas neutrality and alkalinity favor malodor production . Since the pH on oral mucosal surfaces where odor formation occurs is largely determined by the fermentative and putrefactive activities of the adhering bacteria, these acid-base processes are necessarily of major regulatory importance . Because oral malodor and periodontitis both involve excessive oral putrefaction, a better understanding of putrefaction could lead to more substantive methods of oral malodor treatment than exists today, as well as identifying new approaches to amelioration of the bacterial attack on the soft tissues leading to the destruction associated with periodontal disease.

J Dairy Sci, 1992 Sep, 75(9), 2463 - 72
Fatty acids, calcium soaps of fatty acids, and cottonseeds fed to high yielding cows; Sklan D et al.; We examined the effects of dietary fat as cottonseed, fatty acids, or calcium soaps of fatty acids in the rations of high yielding lactating cows receiving low forage . Experiments were with isoenergetic, isonitrogenous diets containing equal amounts of forage . Inclusion of up to 510 g/d of fatty acids in the ration enhanced FCM yield . With cottonseed, increased FCM was mainly due to increased fat yield . Dietary fatty acids tended to increase milk in mid and late lactation and to decrease fat percentage . Calcium soaps of fatty acids enhanced FCM, particularly in early lactation . Feeding cottonseed and fatty acids together did not enhance yield . Effects described may be attributed in part to changes in ruminal fermentation in which cottonseed increased acetate concentrations and fatty acids decreased the ratio of acetate and butyrate to propionate and in part to enhanced efficiency of milk yield when fat was included in the ration.

J Int Med Res, 1992 Sep, 20(5), 371 - 80
Vegetable foods in weaning; Agostoni C et al.; Vegetable foods (cereals, non-starchy vegetables, legumes) make a unique nutritional and metabolic contribution during weaning . They provide proteins that are of low biological value individually but whose value can be raised by consuming appropriate combinations: minimal amounts of lipids, mostly essential polyunsaturated fats; complex carbohydrates; and soluble fibre, which are fermented by colonic flora to short-chain fatty acids that have beneficial effects . Insoluble fibre, minerals, trace elements and vitamins are also nutritionally important components of vegetable foods . Vegetable foods lower the calorific density of meals, modulate nutrient and antigen absorption, and promote a physiological copropoiesis . Recent nutritional surveys have shown that 12-month old children eat an excessive amount of animal proteins . Whole cereals and non-starchy vegetables, including whole legumes, should be routinely eaten during weaning to improve nutritional balance and to make children accustom to eating fibre, which has prophylactic properties . The daily intake of fibre should be progressively increased to 5 g during the first year of life.

Appl Environ Microbiol, 1992 Sep, 58(9), 3150 - 6
Metabolic and energetic control of Pseudomonas mendocina growth during transitions from aerobic to oxygen-limited conditions in chemostat cultures; Verdoni N et al.; Several metabolic fluxes were analyzed during gradual transitions from aerobic to oxygen-limited conditions in chemostat cultures of Pseudomonas mendocina growing in synthetic medium at a dilution rate of 0.25 h-1 . P . mendocina growth was glucose limited at high oxygen partial pressures (70 and 20% pO2) and exhibited an oxidative type of metabolism characterized by respiratory quotient (RQ) values of 1.0 . A similar RQ value was obtained at low pO2 (2%), and detectable levels of acetic, formic, and lactic acids were determined in the extracellular medium . RQs of 0.9 +/- 0.12 were found at 70% pO2 for growth rates ranging from 0.025 to 0.5 h-1 . At high pO2, the control coefficients of oxygen on catabolic fluxes were 0.19 and 0.22 for O2 uptake and CO2 production, respectively . At low pO2 (2%), the catabolic and anabolic fluxes were highly controlled by oxygen . P . mendocina showed a mixed-type fermentative metabolism when nitrogen was flushed into chemostat cultures . Ethanol and acetic, lactic, and formic acids were excreted and represented 7.5% of the total carbon recovered . Approximately 50% of the carbon was found as uronic acids in the extracellular medium . Physiological studies were performed under microaerophilic conditions (nitrogen flushing) in continuous cultures for a wide range of growth rates (0.03 to 0.5 h-1) . A cell population, able to exhibit a near-maximum theoretical yield of ATP (YmaxATP = 25 g/mol) with a number of ATP molecules formed during the transfer of an electron towards oxygen along the respiration chain (P/O ratio) of 3, appears to have adapted to microaerophilic conditions.(ABSTRACT TRUNCATED AT 250 WORDS)

Appl Environ Microbiol, 1992 Sep, 58(9), 2866 - 73
Formation of poly(hydroxybutyrate-co-hydroxyvalerate) by Azotobacter vinelandii UWD; Page WJ et al.; Azotobacter vinelandii UWD formed polyhydroxyalkanoate (PHA) copolymers containing beta-hydroxybutyrate and beta-hydroxyvalerate (HV) when grown in a medium containing glucose as the primary C source and valerate (pentanoate) as a precursor . Copolymer was not formed when propionate was added to the glucose medium but was formed when heptanoate, nonanoate, or trans-2-pentenoate was present . Optimal levels of HV were formed when valerate was added at the time of maximum PHA synthesis, although HV incorporation was not dependent on glucose catabolism . HV content in the polymer was increased from 17 to 24 mol% by adding 10 to 40 mM valerate to glucose medium, but HV insertion into the polymer occurred at a fixed rate . Similarly, the addition of valerate to a fed-batch culture of strain UWD in beet molasses in a fermentor produced 19 to 22 g of polymer per liter, containing 8.5 to 23 mol% HV after 38 to 40 h . The synthesis of HV in these cultures also occurred at a fixed rate (2.3 to 2.8 mol% h-1), while the maximum PHA production rate was 1.1 g liter-1 h-1 . During synthesis of copolymer in batch or fed-batch culture, the yield from conversion of glucose into PHA (YP/S) remained at maximum theoretical efficiency (greater than or equal to 0.33 g of PHA per g of glucose consumed) . Up to 45 mol% C source, but the PHA produced amounted to less than 1 g/liter . The combination of 30 mM valerate as a sole C source and 0.5 mM 4-pentenoate increased the HV content in the polymer to 52 mol%.(ABSTRACT TRUNCATED AT 250 WORDS)

Rev Med Panama, 1992 Sep, 17(3), 208 - 13
{Isolation and identification of Gardnerella vaginalis in women with symptoms of bacterial vaginosis}; Leon X et al.; 70 samples of vaginal secretions were collected from women with bacterial vaginosis syndrome, that were attended in Nuevo Veranillo' Health Center . All samples were tested in order to determinate the presence of amine and to Gram'methods stain to observe the morphologic characteristics of the "Clue" cells (epithelial cells with adhered bacteria) . Samples were cultured in a selective media of blood agar in Columbia base with colistine and nalidixic acid, and incubated in an environment of CO2 at 37 degrees C . Tests of oxidase, catalase, glucid fermentation, hippurate hydrolysis and starch hydrolysis were made on the grown colonies . 27 out of 70 samples resulted in positive cultures for Gardnerella vaginalis, 11 to pregnant women and 16 to nonpregnant women; among these, 14 women used some kind of contraceptive methods as DIU or pill.

J Antibiot (Tokyo), 1992 Sep, 45(9), 1409 - 13
Reveromycins, new inhibitors of eukaryotic cell growth . I . Producing organism, fermentation, isolation and physico-chemical properties; Takahashi H et al.; New antibiotics named reveromycins A, B, C and D were isolated as inhibitors of mitogenic activity induced by epidermal growth factor (EGF) in a mouse epidermal keratinocyte . Reveromycins were produced by a soil actinomycete (strain SN-593) which belongs to the genus Streptomyces.

J Antibiot (Tokyo), 1992 Sep, 45(9), 1404 - 8
Nagstatin, a new inhibitor of N-acetyl-beta-D-glucosaminidase, produced by Streptomyces amakusaensis MG846-fF3 . Taxonomy, production, isolation, physico-chemical properties and biological activities; Aoyagi T et al.; Nagstatin, a new inhibitor of N-acetyl-beta-D-glucosaminidase (NAG-ase) was discovered in the fermentation broth of Streptomyces amakusaensis MG846-fF3 . It was purified by chromatography on Dowex 50W, Avicel and Sephadex LH-20 followed by the treatment of active carbon and then isolated as colorless powder . Nagstatin has the molecular formula of C12H17N3O6 . It is competitive with the substrate, and the inhibition constant (Ki) was 1.7 x 10(-8) M.

Gut, 1992 Sep, 33(9), 1249 - 52
Portal and peripheral blood short chain fatty acid concentrations after caecal lactulose instillation at surgery; Peters SG et al.; The major end products of fermentation, short chain fatty acids (acetate, propionate, butyrate) were measured in portal and peripheral venous blood after the caecal instillation of lactulose at surgery in patients undergoing elective cholecystectomy . Blood samples for short chain fatty acid measurement were taken before and at 15 minute intervals up to 60 minutes after caecal instillation of either 20 ml sterile saline or 6.7 g or 10 g lactulose . Fasting concentrations (n = 28) were (mumol/l, mean (SD)); portal acetate 128.0 (70.8), propionate 34.4 (23.3), butyrate 17.6 (18.4); peripheral acetate 67.0 (23.0), propionate 3.7 (1.2), butyrate traces only . After lactulose there was a rapid rise in portal short chain fatty acids with peak concentrations being reached in 15 to 45 minutes . Mean peak concentrations (mumol/l (SD)) after 10 g lactulose were acetate 240.9 (142.2), propionate 39.0 (17.8) and butyrate 26.9 (17.6) . The changes in acetate concentrations seen in portal blood were reflected in peripheral blood acetate measurements . In contrast with portal blood, only small amounts of propionate and traces of butyrate were found in peripheral blood.

Acta Paediatr Suppl, 1992 Sep, 381, 87 - 92
Effect of milk-containing diets on the severity and duration of childhood diarrhea; Lembcke JL et al.; Individual components of milk from humans and other mammalian species may influence the severity, duration, and nutritional outcome of childhood diarrhea in different ways . Nonetheless, empirical data from clinical trials can be used to assess children's responses to specific milk-containing diets . Factors modifying the response to milk include its source, amount, frequency of feeding, type of processing, and accompanying foods, as well as the type and severity of enteric infection and specific characteristics of the host . Whereas breast-fed infants have less severe diarrhea when breast milk is continued rather than interrupted, infants and children fed with non-human milks tend to have more severe illness than those receiving milk-free or lactose-limited formulas or milk-cereal mixtures . Fermentation of milk may reduce the severity of lactose malabsorption, but additional information regarding the efficacy of yogurt in acute, childhood diarrhea is still neededPublication Types:

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