Fermentations

Scand J Gastroenterol, 1998 Nov, 33(11), 1158 - 63
Fructose-sorbitol malabsorption and symptom provocation in irritable bowel syndrome: relationship to enteric hypersensitivity and dysmotility; Evans PR et al.; BACKGROUND: Fructose-sorbitol (F-S) mixtures can provoke symptoms in irritable bowel syndrome (IBS) patients, and a proportion of IBS patients also have enteric hypersensitivity to distension . We hypothesized, therefore, that sugar malabsorption and fermentation to produce hydrogen gas may provoke symptoms to a greater extent in IBS patients hypersensitive to distension than in those patients without such hypersensitivity . Our aims were therefore to compare, in IBS patients, symptoms and breath hydrogen responses after F-S, on the basis of jejunal sensitivity and jejunal motor function . METHODS: Fifteen female IBS patients (44 +/- 15 years) underwent, on separate occasions, 3-h breath hydrogen analyses after ingesting 10 g lactulose and 25 g fructose with 5 g sorbitol . Jejunal sensitivity and motor function were determined by balloon distension and 24-h manometry studies, respectively . Cumulative symptom scores and breath hydrogen production were analysed on the basis of the presence or absence of jejunal hypersensitivity and dysmotility . RESULTS: Four and seven patients had jejunal hypersensitivity for initial perception and pain, respectively . Eleven, nine, and nine patients had jejunal dysmotility for fasting phase 3, phase 2, and fed motor activity, respectively . Of the patients with symptom provocation after F-S (n = 8 within 3 h, n = 12 within 12 h) or with F-S malabsorption (n = 10), the relative proportion did not differ on the basis of the presence or absence of jejunal hypersensitivity or of motor dysfunction . Symptom scores and hydrogen production also were not different in these subgroups . CONCLUSIONS: Although carbohydrate malabsorption can provoke symptoms in some IBS patients, there is no consistent association between such a phenomenon and the presence of either jejunal hypersensitivity or dysmotility.

Appl Microbiol Biotechnol, 1998 Nov, 50(5), 579 - 82
Carbon catabolite repression of invertase during batch cultivations of Saccharomyces cerevisiae: the role of glucose, fructose, and mannose; Dynesen J et al.; When Saccharomyces cerevisiae are grown on a mixture of glucose and another fermentable sugar such as sucrose, maltose or galactose, the metabolism is diauxic, i.e . glucose is metabolized first, whereas the other sugars are metabolized when glucose is exhausted . This phenomenon is a consequence of glucose repression, or more generally, catabolite repression . Besides glucose, the hexoses fructose and mannose are generally also believed to trigger catabolite repression . In this study, batch fermentations of S . cerevisiae in mixtures of sucrose and either glucose, fructose or mannose were performed . It was found that the utilization of sucrose is inhibited by concentrations of either glucose or fructose higher than 5 g/l, and thus that glucose and fructose are equally capable of exerting catabolite repression . However, sucrose was found to be hydrolyzed to glucose and fructose, even when the mannose concentration was as high as 17 g/l, indicating, that mannose is not a repressing sugar . It is suggested that the capability to trigger catabolite repression is connected to hexokinase PII, which is involved in the in vivo phosphorylation of glucose and fructose.

Appl Microbiol Biotechnol, 1998 Nov, 50(5), 545 - 51
Evaluation of cell recycling in continuous fermentation of enzymatic hydrolysates of spruce with Saccharomyces cerevisiae and on-line monitoring of glucose and ethanol; Palmqvist E et al.; The maximum growth rate of Saccharomyces cerevisiae ATCC 96581, adapted to fermentation of spent sulphite liquor (SSL), was 7 times higher in SSL of hardwood than the maximum growth rate of bakers' yeast . ATCC 96581 was studied in the continuous fermentation of spruce hydrolysate without and with cell recycling . Ethanol productivity by ATCC 96581 in continuous fermentation of an enzymatic hydrolysate of spruce was increased 4.6 times by employing cell recycling . On-line analysis of CO2, glucose and ethanol (using a microdialysis probe) was used to investigate the effect of fermentation pH on cell growth and ethanol production, and to set the dilution rate . Cell growth in the spruce hydrolysates was strongly influenced by fermentation pH . The fermentation was operated in continuous mode for 210 h and a theoretical ethanol yield on fermentable sugars was obtained.

J Bacteriol, 1999 Jan, 181(1), 153 - 60
Sequence diversity of flagellin (fliC) alleles in pathogenic Escherichia coli; Reid SD et al.; To study the molecular evolution of flagellin, the protein subunit specifying flagellar (H) antigens, the fliC genes from 15 pathogenic strains of Escherichia coli were amplified by PCR and sequenced . Comparison of fliC sequences of H6 and H7 strains revealed that alleles have a mosaic structure indicating the occurrence of past horizontal transfer of DNA segments between strains . The close similarity of H7 sequences also indicates the exchange of an entire fliC H7 allele between distant clonal lineages . In addition, the ratio of silent substitutions to amino acid replacements suggests that a short segment in the central region of fliC has been under positive selection in the divergence of H6 and H7 alleles . Phylogenetic analysis demonstrates that the fliC sequences of O157:H7 and O55:H7 serotypes are nearly identical and highly divergent from those of E . coli strains expressing H6 and H2 flagellar antigens . A nonmotile clone of sorbitol-fermenting O157 has rapidly accumulated multiple mutations in fliC, presumably as a result of the silencing of flagellin expression.

J Bacteriol, 1999 Jan, 181(1), 40 - 6
Evidence for a chemiosmotic model of dehalorespiration in Desulfomonile tiedjei DCB-1; Louie TM et al.; Desulfomonile tiedjei DCB-1, a sulfate-reducing bacterium, conserves energy for growth from reductive dehalogenation of 3-chlorobenzoate by an uncharacterized chemiosmotic process . Respiratory electron transport components were examined in D . tiedjei cells grown under conditions for reductive dehalogenation, pyruvate fermentation, and sulfate reduction . Reductive dehalogenation was inhibited by the respiratory quinone inhibitor 2-heptyl-4-hydroxyquinoline N-oxide, suggesting that a respiratory quinoid is a component of the electron transport chain coupled to reductive dehalogenation . Moreover, reductive dehalogenation activity was dependent on 1, 4-naphthoquinone, a possible precursor for a respiratory quinoid . However, no ubiquinone or menaquinone could be extracted from D . tiedjei . Rather, a UV-absorbing quinoid which is different from common respiratory quinones in chemical structure according to mass spectrometric and UV absorption spectroscopic analyses was extracted . ATP sulfurylase, adenosine phosphosulfate reductase, and desulfoviridin sulfite reductase, enzymes involved in sulfate reduction, were constitutively expressed in the cytoplasm of D . tiedjei cells grown under all three metabolic conditions . A periplasmic hydrogenase was detected in cells grown under reductive-dehalogenating and pyruvate-fermenting conditions . A membrane-bound, periplasm-oriented formate dehydrogenase was detected only in cells grown with formate as electron donor, while a cytoplasmic formate dehydrogenase was detected in cells grown under reductive-dehalogenating and pyruvate-fermenting conditions . Results from dehalogenation assays with D . tiedjei whole-cell suspensions and cell extracts suggest that the membrane-bound reductive dehalogenase is cytoplasm oriented . The data clearly demonstrate an enzyme topology in D . tiedjei which produces protons directly in the periplasm, generating a proton motive force by a scalar mechanism.

J Biol Chem, 1998 Dec 25, 273(52), 35268 - 72
A toxic fusion protein accumulating between the mitochondrial membranes inhibits protein assembly in vivo; Beilharz T et al.; When overexpressed in Saccharomyces cerevisiae, beta-galactosidase fusion proteins directed to the mitochondria are toxic, preventing growth of yeast cells on non-fermentable carbon sources (Emr, S . D., Vassarotti, A., Garrett, J., Geller, B . L., Takeda, M., and Douglas, M . G . (1986) J . Cell Biol . 102, 523-533) . We show that such fusion proteins interfere with the assembly of respiratory complexes in the mitochondrial inner membrane, without blocking protein translocation . The gene YME1, encoding an ATP-dependent metalloprotease of the mitochondrial inner membrane, acts as a suppressor of this defect; a 3-fold overexpression of Yme1p is sufficient to restore respiratory complex assembly and mitochondrial function . Detailed knowledge of the topology and effect of the toxic beta-galactosidase fusion proteins will permit the identification and characterization of components that control protein sorting and protein assembly within the mitochondrial inner membrane.

J Anim Sci, 1998 Nov, 76(11), 2912 - 20
Fibrolytic enzyme treatment of barley grain and source of forage in high-grain diets fed to growing cattle; Krause M et al.; We conducted a study to determine the effects of treating barley grain with a fibrolytic enzyme mixture on chewing activities, ruminal fermentation, and total tract digestibility in cattle . We also investigated the potential benefits of using barley straw rather than barley silage as a roughage source in high-grain diets for feedlot cattle . Steers were given ad libitum access to one of four diets that consisted of 95% barley-based concentrate and 5% forage (DM basis) . The concentrate was either control or enzyme-treated, and the forage was either barley silage or barley straw . Applying the enzyme mixture onto the barley lowered the concentrations of dietary ADF and NDF . However, it is not certain when this fiber hydrolysis occurred relative to feed consumption because the fiber analyses were conducted after the study was completed . Enzyme treatment of barley increased total tract dietary ADF digestibility by 28% (P<.05) . Acetate-to-propionate ratio tended to decrease, which suggests that enzymes may have increased ruminal starch digestion as a result of enhanced digestion of barley hulls . Replacing silage with straw increased ADF intake (P<.05) and resulted in 1-h/d increase in rumination time (P<.05) . Even though there was no effect of diet on ruminal pH, replacing silage with straw increased ruminal acetate, as a percentage of total VFA, and total tract ADF digestion (P<.01) . This study demonstrates that using a fibrolytic enzyme mixture in high-grain diets that contain mainly barley grain can improve fiber digestion and grain utilization, but the mode of action is unclear . Straw can be used rather than silage to increase the effective fiber content of a high-grain feedlot diet.

J Anim Sci, 1998 Nov, 76(11), 2845 - 52
Nutritional evaluation of two agroindustrial by-products for ducks and pigs; Ragland D et al.; Forty-eight male White Pekin ducks and 24 crossbred barrows (Landrace or Yorkshire sows; PIC Line 355 boars) were used in three experiments to evaluate the nutritional value of two by-products generated from agricultural industries . In each experiment, test ingredients consisted of a dried meat solubles product (DMS) from swine processing facilities and a yeast fermentation product (YFP) from a commercial source . Soybean meal (SBM) with a CP content of 48% served as the control ingredient in the three experiments . Different batches of each by-product were evaluated in the three experiments utilizing an apparent ME (AME) assay for poultry (Exp . 1 and 2) and a digestibility assay for barrows (Exp . 3) . The nitrogen-corrected AME (AMEn) for SBM, DMS, and YFP in Exp . 1 were 2.909, 2.801, and 3.292 kcal, respectively . The AMEn for SBM, DMS and YFP in Exp 2 were 2.809, 3.207, and 3.565 kcal, respectively . In Exp . 3, diets were formulated such that the test ingredients provided the sole source of amino acids in each experimental diet . The AME of SBM, DMS, and YFP in Exp . 3 were 3.844, 2.208, and 3.552 kcal, respectively . Based on the results of the ME assay for poultry, the DMS product compares well to SBM and seems to be suitable for feeding to ducks . The YFP does not seem to be suitable for feeding nonruminant species based on poor ability to support nitrogen retention in both species (-36% and -20% in Exp . 1 and 2, and 20% in Exp . 3).

Appl Biochem Biotechnol, 1998 Jul, 74(1), 43 - 53
Carob pod: a new substrate for citric acid production by Aspergillus niger; Roukas T; The production of citric acid from carob pod extract by A . niger in surface fermentation was investigated . A maximum citric acid concentration (85.5 g/L), citric acid productivity (4.07 g/L/d), specific citric acid production rate (0.18 g/g/d), and specific sugar uptake rate (0.358 g/g/d) was achieved at an initial sugar concentration of 200 g/L, pH of 6.5, and a temperature of 30 degrees C . Other kinetic parameters, namely, citric acid yield, biomass yield, specific biomass production rate, and fermentation efficiency were maximum at pH 6.5, temperature 30 degrees C, and initial sugar concentration 100 g/L . The external addition of methanol into the carob pod extract at a concentration up to 4% (v/v) improved the production of citric acid.

Yeast, 1998 Nov, 14(15), 1355 - 71
Monovalent cation fluxes and physiological changes of Debaryomyces hansenii grown at high concentrations of KCl and NaCl; Thome-Ortiz PE et al.; Debaryomyces hansenii showed an increased growth in the presence of either 1 M, KCl or 1 M NaCl and a low acidification of the medium, higher for the cells grown in the presence of NaCl . These cells accumulated high concentrations of the cations, and showed a very fast capacity to exchange either Na+ or K+ for the opposite cation . They showed a rapid uptake of 86Rb+ and 22Na+ . 86Rb+ transport was saturable, with K(m) and Vmax values higher for cells grown in 1 M NaCl . 22Na+ uptake showed a diffusion component, also higher for the cells grown with NaCl . Changes depended on growth conditions, and not on further incubation, which changed the internal ion concentration . K+ stimulated proton pumping produced a rapid extrusion of protons, and also a decrease of the membrane potential . Cells grown in 1 M KCl showed a higher fermentation rate, but significantly lower respiratory capacity . ATP levels were higher in cells grown in the presence of NaCl; upon incubation with glucose, those grown in the presence of KCl reached values similar to the ones grown in the presence of NaCl . In both, the addition of KCl produced a transient decrease of the ATP levels . As to ion transport mechanisms, D . hansenii appears to have (a) an ATPase functioning as a proton pump, generating a membrane potential difference which drives K+ through a uniporter; (b) a K+/H+ exchange system; and (c) a rapid cation/cation exchange system . Most interesting is that cells grown in different ionic environments change their studied capacities, which are not dependent on the cation content, but on differences in their genetic expression during growth.

J Biol Chem, 1998 Dec 18, 273(51), 34391 - 8
A Mycoplasma fermentans-derived synthetic lipopeptide induces AP-1 and NF-kappaB activity and cytokine secretion in macrophages via the activation of mitogen-activated protein kinase pathways; Garcia J et al.; Mycoplasma lipoproteins have been demonstrated to stimulate monocytic cells and induce proinflammatory cytokine secretion . In this paper, we show that a synthetic analog of the Mycoplasma fermentans membrane-associated lipopeptide macrophage-activating lipopeptide-2 (MALP-2) induces mRNA synthesis and protein secretion of interleukin-1beta and tumor necrosis factor-alpha in human monocytes/macrophages and the murine macrophage cell line RAW 264.7, whereas the nonlipidated counterpart lacks this effect, underscoring the importance of protein acylation for cell activation . Synthetic MALP-2 (sMALP-2) induced the activation of MAPK family members extracellular signal regulated kinases 1 and 2, c-Jun NH2-terminal kinase, and p38 and induced NF-kappaB and AP-1 transactivation in macrophages . Whereas the specific p38 inhibitor SB203580 abrogated both cytokine synthesis and NF-kappaB and AP-1 transactivation in response to MALP-2, the selective MAPK/extracellular signal-regulated kinase-1 inhibitor PD-98059 decreased interleukin-1beta and tumor necrosis factor-alpha production in response to sMALP-2 without affecting the transactivation of NF-kappaB or AP-1 . These results indicate that activation of MAPKs by sMALP-2 is a crucial event leading to the expression of proinflammatory cytokines . Our findings demonstrate that the synthetic analog of MALP-2 reproduces the macrophage stimulation activity found in different fractions of mycoplasmas . Given that MALP-2 has been recently shown to be expressed at the surface of M . fermentans as a molecular entity, sMALP-2 constitutes a valuable surrogate for investigating immunomodulation by these microorganisms and evaluating the role that this activity plays in the development of inflammatory diseases associated with mycoplasma infections.

J Bacteriol, 1998 Dec, 180(24), 6503 - 10
Region of FLO1 proteins responsible for sugar recognition; Kobayashi O et al.; Yeast flocculation is a phenomenon which is believed to result from an interaction between a lectin-like protein and a mannose chain located on the yeast cell surface . The FLO1 gene, which encodes a cell wall protein, is considered to play an important role in yeast flocculation, which is inhibited by mannose but not by glucose (mannose-specific flocculation) . A new homologue of FLO1, named Lg-FLO1, was isolated from a flocculent bottom-fermenting yeast strain in which flocculation is inhibited by both mannose and glucose (mannose/glucose-specific flocculation) . In order to confirm that both FLO1 and Lg-FLO1 are involved in the yeast flocculation phenomenon, the FLO1 gene in the mannose-specific flocculation strain was replaced by the Lg-FLO1 gene . The transformant in which the Lg-FLO1 gene was incorporated showed the same flocculation phenotype as the mannose/glucose-specific flocculation strain, suggesting that the FLO1 and Lg-FLO1 genes encode mannose-specific and mannose/glucose-specific lectin-like proteins, respectively . Moreover, the sugar recognition sites for these sugars were identified by expressing chimeric FLO1 and Lg-FLO1 genes . It was found that the region from amino acid 196 to amino acid 240 of both gene products is important for flocculation phenotypes . Further mutational analysis of this region suggested that Thr-202 in the Lg-Flo1 protein and Trp-228 in the Flo1 protein are involved in sugar recognition.

Arch Tierernahr, 1998, 51(4), 319 - 26
The comparison of in vitro fermentation kinetics estimated by three different methods; Varadyova Z et al.; Three different methods for the estimation of in vitro fermentation kinetics are compared . The glass syringe, flow gasometer and pressure transducer methods were used for measurement of gas production . The rumen fluid from fistulated Merino sheep mixed with McDougall's buffer (1:1) was used as an inoculum and added at an amount of 35 ml into the fermentation vessels containing 0.25 g of meadow hay . The total gas produced was recorded after 12, 24, 36, 48, 60, 72 and 96 h of incubation . Hay dry matter degradability was the same with all three methods and achieved 56.5 to 58.2% . Total volatile fatty acids were significantly lower with the pressure transducer method than with the syringe and flow gasometer method . Lower values of mol% of butyrate and valerate obtained with the flow gasometer and pressure transducer methods in comparison with the syringe were also observed . Total gas production estimated by the flow gasometer method was lower than that stated by the two other methods . With regard to precision of the used methods syringe method was the best followed by the pressure transducer and flow gasometer method . It can be concluded that in spite of some limitations the pressure transducer method used in this experiment can be regarded as suitable for total gas estimation in in vitro rumen fermentation experiments.

Arch Tierernahr, 1998, 51(4), 279 - 91
Influence of dietary concentrate to forage ratio on the development of rumen mucosa in calves; Zitnan R et al.; Effects of structural and non-structural carbohydrates on the development of rumen fermentation and ruminal mucosa in calves were examined during the weaning period . Barley/soybean meal (SBM) group was fed a concentrate starting from 2 weeks of age, whereas alfalfa group received a mixture of concentrate and alfalfa hay in which the proportion of the latter was gradually increased from 20% to 70% between weeks 2 and 9 of age . The total volatile fatty acid concentration in rumen fluid of calves increased with age, but at 9 weeks there were no significant differences between the two diets (barley/SBM group 153 mmol/l, alfalfa group 150 mmol/l) . Rumen papillae at 9 weeks of age, as compared to 6 weeks of age, were longer and fewer in number per square centimetre mucosa, with larger cut surface . This resulted in a higher surface of papillae per square centimetre mucosa at 9 weeks (barley/SBM group 286 mm2/cm2, alfalfa group 245 mm2/cm2) than at 6 weeks of age (barley/SBM group 217 mm2/cm2, alfalfa group 198 mm2/cm2) . At 9 weeks of age, the pH (barley/SBM 5.0, alfalfa 5.7), the acetate to propionate ratio (barley/SBM 2.2, alfalfa 3.2) as well as the length of the papillae in the ventral ruminal sac (barley/SBM 1.96 mm, alfalfa 2.37 mm) were increased in the alfalfa group when compared to the barley/SBM group (P < 0.1) . In the former group, the proportion of butyrate revealed significantly increased values at 4 and 6 weeks of age . In animals of the barley/SBM group at 9 weeks of age, characteristic protrusions with proliferated thick epithelium occurred on the papillae and increased the surface for absorption . On the epithelium (Stratum corneum) desquamating cells with parakeratosis could be observed . In the alfalfa group the papillae of the ventral ruminal sac were longer, without protrusions . The morphotypes of the adhering rumen microflora differed between the groups . It can be concluded that feeding greater amounts of non-structural carbohydrates increases the surface for absorption of the rumen epithelium in calves . The absence of hyperkeratosis and rumenitis in the barley/SBM group indicated that there is no reason to limit high starch diets in the early weaning period of calves.

Proc Natl Sci Counc Repub China B, 1998 Oct, 22(4), 159 - 65
The effects of starch and protein degradation rates, hay sources, and feeding frequency on rumen microbial fermentation in a continuous culture system; Chen CY et al.; Six continuous culture fermenters were used in three experiments to study the effects of dietary starch and protein degradability combination, hay sources, and feeding frequency on fermentation by rumen microorganisms . Experiments 1 and 2 used a 3 x 2 factorial design in which six diets were formulated to contain low (LS), medium (MS), or high starch degradability (HS) in combination with low (LP) or high protein degradability (HP) . The dietary combinations were (1) LS + HP, (2) LS + LP, (3) MS + HP, (4) MS + LP, (5) HS + HP, and (6) HS + LP . In experiment 1, pangola was used as the hay source, and in experiment 2, alfalfa hay was used . In experiment 3, two starch degradabilities (LS, MS) and two hay sources (alfalfa, A; pangola, P) were combined with two feeding frequencies (2 X/d, 12 X/d) . The dietary combinations were (1) LS + A + 12 X/d, (2) MS + A + 12 X/d, (3) LS + A + 2 X/d, (4) MS + A + 2 X/d, (5) LS + P + 12 X/d, and (6) MS + P + 12 X/d . A CRD design was used for experiment 3 . Two rumen-cannulated Holstein cows fed alfalfa hay ad lib were used as donors of rumen fluid for all experiments . Each period was 6 d in length, with 5 d for adaptation and 1 d for sampling . In experiments 1 and 2, the effects of starch degradability on the composition of rumen microorganisms were significant . The MS or HS with HP had the highest total bacterial and protozoal density (P < 0.05) . As for VFA, pH and nitrogen products, the effects of starch and protein degradability were not significant . There was no interaction between starch and protein degradability on most of microbial composition (ammonia-N, microbial nitrogen) . In experiment 3, 12 X/d feeding frequency (MS + A + 12 X/d vs . MS + A + 12 X/d) resulted in higher pH, which tended to increase bacterial and protozoal density and starch and protein digestibilities . Different hay sources altered the starch and protein synchronization effect on the ammonia-N concentration (mg/dl) and non-ammonia N content (% DM) in the continuous culture system.

Antonie Van Leeuwenhoek, 1998 May, 73(4), 321 - 5
Metabolic characterization of Kloeckera apiculata strains from star fruit fermentation; Romano P et al.; A total of 37 strains of Kloeckera apiculata was isolated during the spontaneous fermentation of star fruit must . Each strain was differentiated from the others on the basis of its capacity to produce acetaldehyde, ethyl acetate, higher alcohols, acetoin and acetic acid . All the strains were characterized by the low production of higher alcohols and the high production of ethyl acetate, whereas consistent differences in the production of acetaldehyde, acetoin and acetic acid served to differentiate star fruit apiculate strains into six different phenotypes, present at different stages of the fermentation process . The metabolic strain diversity found can be interpreted as a natural consequence of environmental conditions, which influenced the frequency and selection of specific apiculate strains . From the biotechnological point of view the different metabolic biotypes represent an important source of strains for potential use as starter cultures for star fruit fermentation.

Eur J Cancer, 1998 Jun, 34(7), 1105 - 10
Flow cytometric analyses of the specific activation of peripheral blood mononuclear cells from healthy donors after in vitro stimulation with a fermented mistletoe extract and mistletoe lectins; Stein GM et al.; Immunostimulatory properties of mistletoe extracts derived from Viscum album L . (VAL) are well described, demonstrating activation especially of T, T-helper cells and monocytes/macrophages . In order to characterise in detail the communication between different cell populations, we studied mistletoe-induced expression of co-stimulatory signals and their ligands by flow cytometry . Peripheral blood mononuclear cells (PBMC) from 15 healthy controls were incubated for 7 days with a fermented VAL extract . VAL significantly upregulated the expression of the co-stimulatory molecule B7.1 (CD80) on monocytes/macrophages, but not B7.2 (CD86) . No significant changes in the expression of either molecules on B cells could be found, suggesting that only monocytes/macrophages act as antigen presenting cells (APCs) in this in vitro system . Purified mistletoe lectins, components of most VAL extracts were also analysed, but did not induce similar responses of monocytes/macrophages . The receptor for B7 molecules, CD28, but not CTLA-4 (CD152), was also found to be significantly enhanced on CD4+ cells after VAL simulation . There was no evidence for activation of a B cell response via the CD40/CD40L pathway . Our data support the concept that stimulation by VAL extracts induces a specific T-helper cell reaction with monocytes/macrophages acting as APCs and purified lectins do not exert the same effects.

FEMS Immunol Med Microbiol, 1998 Nov, 22(3), 241 - 6
Detection of Mycoplasma salivarium and Mycoplasma fermentans in synovial fluids of temporomandibular joints of patients with disorders in the joints; Watanabe T et al.; Thirty-six synovial fluid samples of temporomandibular joints were obtained from 33 patients with pain and anterior disk displacement (closed lock) in the joints . DNAs were prepared from the samples and amplified by a PCR-based assay specific for Mycoplasma salivarium or Mycoplasma fermentans . Of the 36 samples, five (14%), three (8%), and 19 (53%) were positive for M . salivarium, M . fermentans and both, respectively.

Ukr Biokhim Zh, 1998 Jul-Aug, 70(4), 84 - 8
{Content of components of the renin-angiotensin-aldosterone system of blood plasma of healthy children in the early neonatal period}; Voloshin AN et al.; The dynamics of the renin and angiotensin converting ferment activity and of the aldosterone concentration in the plasma of blood by healthy newborn full-term in the first week of the life after the birth was determined . The normative values of the studied indexes were obtained . The researches have shown the considerable functional tension of the renin-angiotensin-aldosterone system, that has a very important signification for optimal course of adaptation and anabolic processes by the children at the very beginning of the postnatal development.

Ukr Biokhim Zh, 1998 Jan-Feb, 70(1), 68 - 74
{Biotransformation of lignocellulse by the fungi Pleurotus floridae (Fries) Kummer and Phellinus igniarius (Linnearus:Fries) Quelet--the pathogens of white rot in trees}; Dombrovs'ka OM et al.; The peculiarities of lignocellulose biotransformation by white-rot fungi Pleurotus floridae and Phellinus igniarius during their solid-state fermentation of wastes of oil-bearing crops processing has been studied . The dynamics of oil-bearing crops processing wastes bioconversion has been studied . It has been marked that P . floridae utilized 20% cellulose and lignin during 9 weeks and 40% lignin and 30% cellulose during all period of fermentation (19 weeks) . The fungus P . igniarius utilized mainly cellulose (40% cellulose and 24% lignin in 19 weeks) . Lignin-degradative capacity of P . floridae (KL = 0.57) and P . igniarius (KL = 0.34) has been quantitatively estimated . The degradation of plant biopolimers corresponded to the production of ligninolytic (laccase, Mn(2+)-dependent peroxidase,) and cellulolytic (CMC-cellulase) enzymes . The component and isoenzyme content of ligninolytic enzyme complex of fungi Pleurotus floridae and Phellinus igniarius has been determined.

Ukr Biokhim Zh, 1998 Jan-Feb, 70(1), 63 - 8
{Protective effect of cresacin in D-galactosamine-induced acute experimental hepatitis}; Korda MM; Antioxidant properties of cresacin were studied on the model of galactosamine hepatitis and on the isolated liver cells of white male rats . It has been shown, that cresacin in a dose of 20 mg/kg effectively inhibits the processes of lipid peroxidation induced by hepatotoxin . Cresacin also normalized some components of fermentative and non-enzymatic antioxidant system . In particular the indexes of the activity of superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and the level of reduced glutathione, total phospholipids and ascorbic acid was increased for certain . In vitro, on the isolated hepatocytes, cresacin showed the dose-dependent antioxidant effect . This fact is confirmed by its property to inhibit the speed of formation of the malonic dialdehyde in the incubation medium.

Onderstepoort J Vet Res, 1998 Jun, 65(2), 87 - 95
Three new species of ciliated Protozoa from the hindgut of both white and black wild African rhinoceroses; Van Hoven W et al.; This report deals with the effect of the mode of feeding of the hindgut-fermenting herbivorous rhinoceros on the species of Protozoa fermenting the ingesta, as demonstrated by the proposed three new species of ciliated Protozoa: Didesmis synciliata differing from D . ovalis in having syncilia in place of simple cilia, Blepharoconus dicerotos being twice the size of B . cervicalis, and Blepharosphaera ceratotherii being one third the size of B . intestinalis . The findings are in line with the biological tenet that in herbivores the composition of the diet is the major factor determining the composition of the digestive organisms.

Am J Clin Nutr, 1998 Dec, 68(6), 1276 - 83
Production rate of acetate during colonic fermentation of lactulose: a stable-isotope study in humans; Pouteau E et al.; BACKGROUND: Breath tests are currently used to qualitatively assess colonic fermentation; no quantitative estimations are available for healthy subjects . OBJECTIVE: This study describes a stable-isotope-dilution method to measure acetate production quantitatively from colonic bacterial fermentation . DESIGN: Six volunteers received a primed, constant, intravenous infusion of {1-13C}acetate at a rate of 1.01 +/- 0.04 micromol x kg(-1) x min(-1) for 7 h . They ingested 20 g pure lactulose after 1 h of the tracer infusion . Expired air and arterialized venous blood were sampled every 15 min . RESULTS: Before lactulose intake, the breath-hydrogen concentration was 7 +/- 2 ppm and the plasma acetate concentration and isotopic enrichment were 141 +/- 14 micromol/L and 14.8 +/- 1.4 moles percent excess, respectively . Whole-body acetate turnover was 6.0 +/- 0.7 micromol x kg(-1) x min(-1) . After lactulose ingestion, maximum breath hydrogen and acetate concentrations reached 63 +/- 15 ppm (P = 0.004) and 313 +/- 25 micromol/L (P = 0.002), respectively, whereas {13C}acetate enrichment decreased to 9.9 +/- 1.3 moles percent excess (P = 0.03) . Whole-body acetate turnover increased to 9.8 +/- 1.5 micromol x kg(-1) x min(-1) and later decreased almost to baseline values . Colonic lactulose fermentation yielded 140 +/- 12 mmol acetate over 6 h, representing 86% of the production based on stoichiometric equations . CONCLUSION: This new method provides a quantitative estimate of colonic carbohydrate fermentation via evaluation of acetate production.

Eur J Clin Nutr, 1998 Nov, 52(11), 790 - 5
Retrograded high-amylose corn starch reduces cholic acid excretion from the small bowel in ileostomy subjects; Langkilde AM et al.; OBJECTIVE: To study the short-term effect of resistant starch (RS) from retrograded high-amylose corn starch (HACS) on the excretion of bile acids and nutrients from the small bowel in humans . DESIGN: Seven healthy ileostomists were given a controlled, constant diet during three days . On days 2 and 3, 100 g/d of one of two test-products--drum-dried ordinary corn starch and autoclaved retrograded HACS, providing 5 and 39 g RS/d, respectively--was given, in random order . Ileostomy effluents were collected for 24 h per day and analysed for wet weight, dry weight, energy, bile acids and nutrients . SETTINGS: In-patient study at the metabolic ward, Department of Clinical Nutrition, Sahlgrenska University Hospital, Goteborg . RESULTS: Consumption of retrograded HACS caused (1) a 42% lower mean excretion of cholic acid (P = 0.024); (2) a 42% lower mean wet weight concentration of bile acids (P < 0.001); (3) a 70% increased excretion of dry weight (P = 0.001); and (4) a 41% increased excretion of energy (P= 0.036) compared with consumption of drum-dried ordinary corn starch . CONCLUSION: The reduced ileal excretion and concentration of cholic acid would be protective regarding colon cancer risk in addition to the increased fermentation substrate provided by RS and other energy-yielding components.

EMBO J, 1998 Dec 1, 17(23), 7002 - 8
Sip4, a Snf1 kinase-dependent transcriptional activator, binds to the carbon source-responsive element of gluconeogenic genes; Vincent O et al.; The carbon source-responsive element (CSRE) mediates transcriptional activation of the gluconeogenic genes during growth of the yeast Saccharomyces cerevisiae on non-fermentable carbon sources . Previous studies have suggested that the Cat8 protein activates the expression of CSRE-binding factors . We show here that one of these factors is Sip4, a glucose-regulated C6 zinc cluster activator which was identified by its interaction with the Snf1 protein kinase . We present genetic evidence that Sip4 contributes to transcriptional activation by the CSRE and biochemical evidence that Sip4 binds to the CSRE . Binding was detected in electrophoretic mobility shift assays with both yeast nuclear extracts and a bacterially expressed Sip4 fusion protein . Evidence suggests that Sip4 also activates the expression of other CSRE-binding proteins . Finally, we show that Cat8 regulates SIP4 expression and that overexpression of Sip4 compensates for loss of Cat8 . We propose a model for activation by the CSRE in which Sip4 and Cat8 have related functions, but Cat8 is the primary regulator because it controls Sip4 expression.

Clin Tech Small Anim Pract, 1998 Nov, 13(4), 211 - 6
Interventional nutrition for gastrointestinal disease; Hickman MA; Nutritional intervention plays a key role in the successful management of gastrointestinal disease . This article focuses on several novel areas of nutritional intervention that are becoming increasingly important in gastrointestinal disease, including short-chain fatty acids, omega-3 polyunsaturated fatty acids and glutamine . Short-chain fatty acids are the principal end-products of bacterial fermentation of dietary fibers and have profound effects on normal intestinal cell metabolism and proliferation . Short-chain fatty acids have the potential to improve overall intestinal health, stimulate intestinal healing, and decrease intestinal inflammation . Omega-3 fatty acids, from dietary sources or supplements, may also be useful in decreasing intestinal inflammation and in preventing intestinal cancer . Finally, glutamine also may play an important role in the nutritional management of gastrointestinal disease.

Biotechnol Prog, 1998 Nov, 14(6), 890 - 6
Pretreatment for cellulose hydrolysis by carbon dioxide explosion
Zheng Y, Lin H, Tsao GT.
Cellulosic materials were treated with supercritical carbon dioxide to increase the reactivity of cellulose, thereby to enhance the rate and the extent of cellulose hydrolysis . In this pretreatment process, the cellulosic materials such as Avicel, recycled paper mix, sugarcane bagasse and the repulping waste of recycled paper are placed in a reactor under pressurized carbon dioxide at 35 degreesC for a controlled time period . Upon an explosive release of the carbon dioxide pressure, the disruption of the cellulosic structure increases the accessible surface area of the cellulosic substrate to enzymatic hydrolysis . Results indicate that supercritical carbon dioxide is effective for pretreatment of cellulose . An increase in pressure facilitates the faster penetration of carbon dioxide molecules into the crystalline structures, thus more glucose is produced from cellulosic materials after the explosion as compared to those without the pretreatment . This explosion pretreatment enhances the rate of cellulosic material hydrolysis as well as increases glucose yield by as much as 50% . Results from the simultaneous saccharification and fermentation tests also show the increase in the available carbon source from the cellulosic materials for fermentation to produce ethanol . As an alternative method, this supercritical carbon dioxide explosion has a possibility to reduce expense compared with ammonia explosion, and since it is operated at the low temperature, it will not cause degradation of sugars such as those treated with steam explosion due to the high-temperature involved.

Syst Appl Microbiol, 1998 Aug, 21(3), 340 - 5
The fermenting bacterium Malonomonas rubra is phylogenetically related to sulfur-reducing bacteria and contains a c-type cytochrome similar to those of sulfur and sulfate reducers; Kolb S et al.; Malonomonas rubra is a microaerotolerant fermenting bacterium which can maintain its energy metabolism for growth by decarboxylation of malonate to acetate . 16S rRNA sequence analysis revealed that M . rubra is closely related to the cluster of mesophilic sulfur-reducing bacteria within the delta subclass of the Proteobacteria, with the fermenting bacterium Pelobacter acidigallici and the sulfur reducers Desulfuromusa kysingii, D . bakii and D . succinoxidans as closest relatives . The cells contain high amounts (up to 12% of the total cell protein content) of a c-type cytochrome which is present mainly (> 60%) in the cytoplasm and to minor parts in the periplasm (> 20%) and associated with the membrane fraction (> 10%), independent of the growth substrate . This cytochrome is a tetraheme cytochrome of 13,700 Da molecular mass with a midpoint redox potential of -0.210 V.M . rubra does not reduce sulfur or ferric iron compounds . Since this cytochrome appears not to be involved in the energy metabolism it is concluded that it is a remnant of sulfur-reducing ancestors of this bacterium, without a conceivable physiological function in its present energy metabolism.

Plant Foods Hum Nutr, 1998, 52(2), 133 - 40
Physicochemical properties and garification (gari yield) of selected cassava cultivars in Rivers State, Nigeria; Achinewhu SC et al.; Gari was processed from six different cassava cultivars TMS 3575, TMS 3044, hormone treated variety (HTV), TMS 30555, TMS 40944 and TMS 30572 . Chemical analyses of the gari samples showed pH values of: 4.0, 4.0, 3.9, 3.6, 3.4, 3.6 and total titratable acidity of 0.99, 0.99, 0.98, 0.85, 0.96, 0.85 (% lactic acid) for TMS 3575, 3044, HTV, 30555, 30572, and 40944 respectively . Physical characteristics of the samples showed the swelling index of 264.5%, 223.5%, 364.0%, 321.3%, 241.3% and 232.7%, water absorption capacity of 1.0 ml/g, 0.8, 1.5, 1.9, 1.7, 1.9 ml g(-l) sample, relative bulk density of 0.29, 0.30, 0.15, 0.17, 0.15 (g/cm3) and gari yield of 34%, 21%, 33%, 24%, and 23%, for cultivars, TMS 3575 (2), 3044, HTV, 30555, 30572, 40944 respectively . Sensory evaluation showed a significant difference (p < 0.05) in quality and overall acceptability among the samples while Tukey test showed a difference (p<0.05) between HTV and between 3575 and 3044 . The cassava pulp from the cultivars and their corresponding gari had HCN content (mg/100 g) ranging from 7.9 to 9.3 for pulp and 1.1 to 1.5 for gari, respectively . The 72 hours fermentation period reduced the HCN in all cultivars by 85%, which is considered to be a safe level for human consumption.

Biosens Bioelectron, 1998 Oct 15, 13(9), 1023 - 8
H+ISFET-based biosensor for determination of penicillin G; Liu J et al.; A biosensor based on an H+ ion sensitive field effect transistor (H+(-)ISFET) and penicillin G acylase has been developed . The response time of the sensor to different concentrations of penicillin G was 30 s . In a 20 mM phosphate buffer at pH 7.0, the linear range of the calibration curve was from 0.5 to 8 mM . The coefficients of variation for three samples with 20 repeated measurements were below 5% . Stability of the sensor could reach about 6 months and more than 1000 runs were performed without a significant decrease of the output value . The sensor was tested for measurement of the penicillin G content in penicillin fermentation both . Forty samples with low and high concentrations of penicillin G were chosen for the correlation test . The values assayed by the sensor method were compared with the values assayed by HPLC method, the correlation coefficient (r) was 0.9944 and the regression equation was y = 1.034X - 2083.7, respectively . The different measuring methods are discussed in the text.

J Dairy Sci, 1998 Nov, 81(11), 3063 - 74
The use of fiber concentrations for ration formulation; Varga GA et al.; Dairy cattle require fibrous feedstuffs in the diet . However, defining the fiber requirements requires knowledge of many interacting components within the diet as well as how the feed is allocated and processed . To meet the demands of high producing dairy cows for energy, diets consist of large quantities of concentrates and high quality forages containing relatively low amounts of fiber . However, to maintain normal rumen function and milk fat percentage, a large portion of the fiber needs to come from forage . Current National Research Council recommendations are a minimum of 25 to 28% dietary neutral detergent fiber, 75% of which is supplied from forage . Chemical measures of fiber alone are not adequate for ration balancing; fiber varies in its effectiveness at stimulating chewing . This variation is greater when feeds contain high amounts of by-products in place of forages . The effectiveness in stimulation of chewing of fiber is variable as the particle size and retention times of indigestible and digestible fiber vary . Currently, little information exists about the fiber requirements of the cow from immediately postcalving until peak lactation . Early lactation cows are clearly more limited by physical fill than are cows in mid and late lactation . Rations based on nonforage fiber sources (> 45% neutral detergent fiber on a dry matter basis) are being evaluated for early lactation cows . Information is needed to determine the variation in the amount of fermentation acids produced, chewing activity, and amount of saliva secreted as these all contribute to the physical effectiveness of fiber.

Indian J Exp Biol, 1998 Aug, 36(8), 816 - 9
Agar immobilized yeast cells in tubular reactor for ethanol production; Nigam JN et al.; Saccharomyces cerevisiae cells were immobilized in agar gel and used in a tubular reactor for conversion of cane molasses to ethanol at 30 degrees C, pH 4.5 . Reactor was used in a continuous operation to test the operational stability and ethanol productivity . After 100 days of continuous fermentation at a dilution rate of 0.67 hr-1, some deactivation of cells was observed, but ethanol productivity was recovered by reactivating the cells by sparging air intermittently . It was found that intermittent reactivation during continuous operation was very important for satisfactory performance of the reactor . During operation, gel beads maintained their rigidity . Maximum ethanol concentration (94.9 g/L) was obtained with a feed containing 255 g/L reducing sugar, at a dilution rate of 0.2 hr-1 . Maximum volumetric productivity (79.5 g ethanol /L/hr), specific ethanol productivity (0.58 g ethanol/g cells/hr), specific sugar uptake rate (1.12 g sugar/g cells/hr) and ethanol yield coefficient (0.43 g ethanol/g sugar) were obtained with a feed containing 195 g/L reducing sugar at a dilution rate of 1.33 hr-1.

J Med Entomol, 1998 Nov, 35(6), 967 - 76
Laboratory and field evaluations of oviposition responses of Aedes albopictus and Aedes triseriatus (Diptera: Culicidae) to oak leaf infusions; Trexler JD et al.; Organic infusions created by fermenting white oak (Quercus alba L.) leaves in water were evaluated as sources of attractant odorants and contact oviposition stimulants for gravid Aedes albopictus (Skuse) and Aedes triseriatus (Say) . Infusions were bioassayed in the laboratory by giving single females a choice of ovipositing in 1 container with infusion and 7 containers with water . Ae . albopictus laid significantly more eggs in containers with infusion, regardless of concentration (dilutions ranging from 10 to 100%) or age (fermentation periods of 7, 28, 60 d), than in containers holding water . The largest proportion of eggs (76.8%) was deposited in response to a 60% concentration of 7-d-old infusion . In contrast, Ae . triseriatus exhibited variable oviposition responses but generally deposited the largest number of eggs in only a few concentrations of older age infusions . In binary "sticky screen" bioassays, there was no difference between the numbers of females attracted to infusion or water, indicating that oviposition responses to infusion were mediated by contact chemostimulants rather than by attraction to odorants . Oviposition responses to infusions by field populations of Ae . albopictus and Ae . triseriatus in Raleigh, NC, were evaluated with pairs of oviposition traps, one containing infusion and the other containing water . Generally, Ae . albopictus laid significantly more eggs in ovitraps containing infusion regardless of its age (7, 28, and 60 d old) or the mass of leaves fermented (126 g = 1x or 504 g = 4x) than in water . In contrast, Ae . triseriatus deposited an equivalent number of eggs in traps containing water or 1x, 80% infusion regardless of its age; however, the oviposition response to ovitraps containing 4x, 7-d-old, 50% infusion was significant . Placement of an automobile tire behind an ovitrap did not increase the number of Ae . albopictus eggs laid in ovitraps containing 4x, 7-d-old, 50% infusion or water relative to ovitraps without a tire . Our research indicates that baiting ovitraps with oak leaf infusion would increase the sensitivity of surveillance efforts for Ae . albopictus and Ae . triseriatus.

Appl Environ Microbiol, 1998 Dec, 64(12), 4891 - 6
Expression of active human tissue-type plasminogen activator in Escherichia coli; Qiu J et al.; The formation of native disulfide bonds in complex eukaryotic proteins expressed in Escherichia coli is extremely inefficient . Tissue plasminogen activator (tPA) is a very important thrombolytic agent with 17 disulfides, and despite numerous attempts, its expression in an active form in bacteria has not been reported . To achieve the production of active tPA in E . coli, we have investigated the effect of cooverexpressing native (DsbA and DsbC) or heterologous (rat and yeast protein disulfide isomerases) cysteine oxidoreductases in the bacterial periplasm . Coexpression of DsbC, an enzyme which catalyzes disulfide bond isomerization in the periplasm, was found to dramatically increase the formation of active tPA both in shake flasks and in fermentors . The active protein was purified with an overall yield of 25% by using three affinity steps with, in sequence, lysine-Sepharose, immobilized Erythrina caffra inhibitor, and Zn-Sepharose resins . After purification, approximately 180 microgram of tPA with a specific activity nearly identical to that of the authentic protein can be obtained per liter of culture in a high-cell-density fermentation . Thus, heterologous proteins as complex as tPA may be produced in an active form in bacteria in amounts suitable for structure-function studies . In addition, these results suggest the feasibility of commercial production of extremely complex proteins in E . coli without the need for in vitro refolding.

J Nat Prod, 1998 Nov, 61(11), 1379 - 82
Quanolirones I and II, two new human cytomegalovirus protease inhibitors produced by Streptomyces sp . WC76535; Qian-Cutrone J et al.; Two new naphthacenequinone glycosides, quanolirones I (1) and II (2) were isolated, together with the known compound galtamycin from the fermentation broth of Streptomyces sp . WC76535 . The structures 1 and 2 were established by analysis of their spectroscopic data and by comparison of their data to those of galtamycin . Compounds 1, 2, and galtamycin showed inhibitory activity against HCMV protease with IC50 values of 14, 35, and 52 microM, respectively.

Lett Appl Microbiol, 1998 Nov, 27(5), 243 - 6
Design and evaluation of malolactic enzyme gene targeted primers for rapid identification and detection of Oenococcus oeni in wine; Zapparoli G et al.; Rapid identification and detection of Oenococcus oeni was achieved by species-specific PCR . Two primers flanking a 1025 bp region of the O . oeni gene encoding the malolactic enzyme were designed . The expected DNA amplificate was obtained only when purified DNA from O . oeni was used . The identity of PCR product was confirmed by nested PCR and restriction analysis . Within 8 h, 10(3) cfu ml-1 of oenococci were detected in fermenting grape must containing 10(7) yeast cells, whereas the detection limit in wine was 10(4) cfu ml-1 . The rapidity and reliability of the PCR procedure established suggests that the method may be profitably applied in winery laboratories for quality control.

J Appl Microbiol, 1998 Nov, 85(5), 779 - 89
Dynamics of indigenous and inoculated yeast populations and their effect on the sensory character of Riesling and Chardonnay wines; Egli CM et al.; To study the impact of yeast populations on wine flavour and to better understand yeast growth dynamics, wines were produced by the (i) indigenous microflora, (ii) vigorous yeast starter EC1118 and (iii) slowly fermenting yeast Assmannshausen . Sensory analysis revealed that wines differed depending on the fermentation type . However, these yeast-related differences did not exceed the varietal character . Both added starter cultures clearly dominated the Saccharomyces population from the middle of fermentation onwards . The starter cultures differed in their repression of indigenous non-Saccharomyces yeast . EC1118 limited growth of non-Saccharomyces yeasts more strongly than Assmannshausen . Sulphite addition further repressed growth of non-Saccharomyces yeasts . On completion, more than one Saccharomyces strain was present in each fermentation, with the largest variety in the non-inoculated and the smallest in the EC1118-inoculated fermentation . Results from the two genetic assays, karyotyping, and PCR using delta-primers were not fully equivalent, limiting the usefulness of delta-PCR in studies of native Saccharomyces yeasts.

J Food Prot, 1998 Nov, 61(11), 1515 - 7
Growth and oil production of Apiotrichum curvatum in tomato juice; Akindumila F et al.; The lipid-accumulating yeast Apiotrichum curvatum ATCC 20509 (formerly Candida curvata D) grew in shake flask culture in freshly prepared tomato juice or tomato pulp; growth was improved when the medium was supplemented with sucrose and a basal salts mixture . Under controlled conditions in the fermentor, biomass and oil production reached a maximum at 96 h, compared with 130 h in shake flasks . Biomass production increased with the addition of 0.3% (wt/vol) urea to the juice, but decreased with the addition of 0.5% (wt/vol) yeast extract or Casamino Acids . The total amount of lipid produced and the percent of intracellular oil per cell dry weight were greatest in juice supplemented with 0.3% urea.

J Biotechnol, 1998 Oct 19, 65(1), 69 - 80
Bioprocess monitoring: an optical biosensor for rapid bioproduct analysis; Gill A et al.; The use of an optical biosensor for rapid bioproduct analysis is described . The biosensor, which is sensitive to changes in the concentration of bioproduct at its biologically active surface, has been shown to provide concentration data within 10 s of sample addition to the device . This has been achieved through the use of linear regression analysis to extract information from the early part of the biosensor interaction profiles . The system has been used to monitor both the production and purification of antibody fragments expressed during batch fermentation of recombinant Escherichia coli . Data obtained using the biosensor have been used to provide real-time profiles describing the location of antibody fragments during bioprocessing . Biosensor data have also been compared with those obtained from ELISA, the traditional method of retrospective analyses of samples collected during bioprocessing.

Int J Syst Bacteriol, 1998 Oct, 48 Pt 4, 1383 - 7
Syntrophobacter fumaroxidans sp . nov., a syntrophic propionate-degrading sulfate-reducing bacterium; Harmsen HJ et al.; A syntrophic propionate-oxidizing bacterium, strain MPOBT, was isolated from a culture enriched from anaerobic granular sludge . It oxidized propionate syntrophically in co-culture with the hydrogen- and formate-utilizing Methanospirillum hungateii, and was able to oxidize propionate and other organic compounds in pure culture with sulfate or fumarate as the electron acceptor . Additionally, it fermented fumarate . 16S rRNA sequence analysis revealed a relationship with Syntrophobacter wolinii and Syntrophobacter pfennigii . The G + C content of its DNA was 60.6 mol%, which is in the same range as that of other Syntrophobacter species . DNA-DNA hybridization studies showed less than 26% hybridization among the different genomes of Syntrophobacter species and strain MPOBT . This justifies the assignment of strain MPOBT to the genus Syntrophobacter as a new species . The name Syntrophobacter fumaroxidans is proposed; strain MPOBT (= DSM 10017T) is the type strain.

Int J Syst Bacteriol, 1998 Oct, 48 Pt 4, 1205 - 12
Pseudoalteromonas tunicata sp . nov., a bacterium that produces antifouling agents; Holmstrom C et al.; A dark-green-pigmented marine bacterium, previously designated D2, which produces components that are inhibitory to common marine fouling organisms has been characterized and assessed for taxonomic assignment . Based on direct double-stranded sequencing of the 16S rRNA gene, D2T was found to show the highest similarity (93%) to members of the genus Pseudoalteromonas . The G + C content of D2T is 42 mol%, and it is a facultatively anaerobic rod and oxidase-positive . D2T is motile by a sheathed polar flagellum, exhibited non-fermentative metabolism and required sodium ions for growth . The strain was not capable of using citrate, fructose, sucrose, sorbitol and glycerol but it utilizes mannose and maltose and hydrolyses gelatin . The molecular evidence, together with phenotypic characteristics, showed that this bacterium which produces an antifouling agent constitutes a new species of the genus Pseudoalteromonas . The name Pseudoalteromonas tunicata is proposed for this bacterium, and the type strain is D2T (= CCUG 26757T).

Int J Syst Bacteriol, 1998 Oct, 48 Pt 4, 1197 - 204
Entomoplasma freundtii sp . nov., a new species from a green tiger beetle (Coleoptera: Cicindelidae); Tully JG et al.; A mollicute (strain BARC 318T) isolated from gut tissue of a green tiger beetle (Coleoptera: Cicindelidae) was found by dark-field microscopy to consist of non-helical, non-motile, pleomorphic coccoid forms of various sizes . In ultrastructural studies, individual cells varied in diameter from 300 to 1200 nm, were surrounded by a cytoplasmic membrane and showed no evidence of cell wall . The organisms were readily filterable through membrane filters with mean pore diameters of 450 and 300 nm, with unusually large numbers of organisms filterable through 200 nm pore membrane filters . Growth occurred over a temperature range of 15-32 degrees C with optimum growth at 30 degrees C . The organism fermented glucose and hydrolysed arginine but did not hydrolyse urea . Strain BARC 318T was insensitive to 500 U penicillin ml-1 and required serum or cholesterol for growth . It was serologically distinct from all currently described sterol-requiring, fermentative Mycoplasma species and from 12 non-sterol-requiring Mesoplasma species, 13 non-sterol-requiring Acholeplasma species and 5 previously described sterol-requiring Entomoplasma species . Strain BARC 318T was shown to have a G + C content of 34 mol% and a genome size of 870 kbp . The 16S rDNA sequence of strain BARC 318T was compared to 16S rDNA sequences of several other Entomoplasma species and to other representative species of the genera Spiroplasma and Mycoplasma, and to other members of the class Mollicutes . These comparisons indicated that strain BARC 318T had close phylogenetic relationships to other Entomoplasma species . On the basis of these findings and other similarities in morphology, growth and temperature requirements and genomic features, the organism was assigned to the genus Entomoplasma . Strain BARC 318T (ATCC 51999T) is designated the type strain of Entomoplasma freundtii sp . nov.

Biosens Bioelectron, 1998 Oct 1, 13(7-8), 875 - 80
Development of a biosensor for monitoring of glycerol during alcoholic fermentation; Compagnone D et al.; A biosensor for the measurement of glycerol in FIA was constructed using covalently immobilized glycerokinase and glycerol-3-phosphate oxidase in conjunction with a Pt based hydrogen peroxide probe . Different immobilization strategies have been studied including random and asymmetric immobilization onto a polymeric support and immobilization onto two different membranes . The latter resulted in the best configuration for batch measurement . The most effective configuration for measurement in FIA was the immobilization of glycerokinase in a glass beads reactor coupled with glycerol-3-phosphate oxidase on a preactivated Immobilon AV membrane kept at the electrode surface . Using a 250-microliter injection loop, 3 mmol ATP(Mg+2) in 0.1 M borate buffer pH 8.5 and a flow rate of 0.5 ml/min, a linear response in the 2 x 10(-6)/10(-3) mol/l range and a detection limit of 5 x 10(-7) mol/l were obtained for glycerol . Lifetime of the glycerol-3-phosphate membrane was extended up to 1 month by storage in the working buffer containing 1% DEAE-dextran and 5% lactitol . More than 350 samples can be assayed with this system . The biosensor was used to monitor off-line glycerol production during alcoholic fermentations carried out at different pHs and temperatures.

Vopr Pitan, 1998, (4), 5 - 8
{Proteolysis of immunoglobulins--biologically-active supplement in a fermented milk in gastrointestinal system of rats}; Gmoshinskii IV et al.; There was studied a possibility of immunochemical specificity conservation in immunoglobulins ingested with a bolus of experimental fermented milk formula . Adult rats received intragastrically 4 ml of studied formula supplied with gamma-globulin fraction of normal serum . Concentration was measured of IgG, IgA and IgM in gastric and intestinal content and in feces 1, 2 and 30 hours later the ingestion by radial immunodiffusion and ELISA . At two hours of digestion up to 25.7% of IgG could be recovered from gastrointestinal tract in immunoprecipitated form . IgA and IgM macromolecules degraded in the intestinal lumen with significantly higher rate . Only trace amounts of IgG were revealed in feces . Molecular weight of immunoprecipitated IgG in distal intestinal compartment was equal to 50 kD according gel filtration data . This corresponds to large breakdown fragments of Fab or Fc type . It was concluded that this fragments could stimulate in non-specific manner some kinds of immunocompetent lymphocytes of intestinal tract.

J Med Microbiol, 1998 Nov, 47(11), 983 - 6
Use of PCR to detect mycoplasma DNA in respiratory tract specimens from adult HIV-positive patients; Cultrera R et al.; The polymerase chain reaction (PCR) was evaluated retrospectively for its ability to detect Ureaplasma urealyticum and Mycoplasma spp . in respiratory tract specimens obtained from adult patients with AIDS . Mycoplasma DNA was detected in specimens from 12 of 84 patients . Of the 107 specimens tested, 13 and seven positive PCR results were obtained with the genus- and species-specific oligonucleotide primers used, respectively, in two different steps . With the latter, one sample was positive for U . urealyticum plus M . hominis, another for M . fermentans plus M . salivarium, and five others were positive for M . salivarium . The unexpected detection of U . urealyticum DNA in respiratory secretions from an adult AIDS patient suggested that this urogenital mycoplasma could have a role in determining or exacerbating respiratory tract infections in the HIV-positive population, but that its low rate of isolation could be related to the frequent failure of methods used currently to detect mycoplasmas.

Biodegradation, 1998, 9(2), 113 - 8
Alcohol and acid formation during the anaerobic decomposition of propylene glycol under methanogenic conditions; Veltman S et al.; Intermediates formed during the anaerobic decomposition of propylene glycol under methanogenic conditions were studied using a serum bottle technique . The pathway is similar to the anaerobic decomposition of ethylene glycol as previously reported . For both compounds, the decomposition is believed to proceed via an initial disproportionation of the glycol to form equal molar amounts of the volatile fatty acid and normal alcohol of the same chain length . In the case of ethylene glycol, disproportionation results in the formation of acetate and ethanol, while disproportionation of propylene glycol produces propionate and n-propanol . Following disproportionation, the alcohols produced from glycol fermentation are oxidized to their corresponding volatile fatty acid with the reduction of protons to form hydrogen . Ethanol and propionate oxidation to acetate proceeds via a well-established syntrophic pathway that is favorable only under low hydrogen partial pressures . Subsequent degradation of acetate proceeds via acetoclastic methanogenesis with the production of carbon dioxide and methane . Despite the production of hydrogen in the initial steps of glycol degradation, both compounds are completely degradable under the methanogenic conditions tested in this study.

Electrophoresis, 1998 Oct, 19(14), 2474 - 8
Off-line quantitative monitoring of plasmid copy number in bacterial fermentation by capillary electrophoresis; Breuer S et al.; Capillary electrophoresis (CE) is an effective instrumental alternative to conventional slab gel electrophoresis in the determination of plasmid copy number during recombinant protein formation processes . This analytical setup provides efficient separation of different species of linearized plasmid molecules and quantification by UV detection . Both fused silica and gel-filled capillaries are assessed with respect to peak resolution and reproducibility . The application of coated capillaries eliminates the electroosmatic flow to a large extent, resulting in excellent separation of DNA fragments . The application of UV detection enables the analysis of linearized plasmid DNA with a conventional laboratory CE device . All investigated plasmids show good peak resolution due to their significant differences in molecular size, which is essential for sufficient separation of individual DNA molecules.

Eur J Haematol, 1998 Oct, 61(4), 250 - 4
Intestinal permeability in patients with acute myeloid leukemia; Sundstrom GM et al.; Intestinal permeability was studied in patients with acute myeloid leukemia (AML) before, during and after chemotherapy . Intestinal permeability was determined by the lactulose (La)/mannitol (Ma) absorption test in 16 adult patients with de novo AML . The hydrogen breath test was used to disclose bacterial fermentation of the test substances in the small intestine . The permeability was found significantly increased (p<0.02) in the patients before induction chemotherapy treatment . During induction treatment and throughout the cytopenic period the intestinal permeability was constantly and significantly increased, compared with controls . In patients with abnormally increased permeability, no increase in hydrogen breath test result was noted . From our results it can be concluded that increased intestinal permeability is present in AML patients before commencing chemotherapy . Factors other than chemotherapy would seem to be more important regarding the occurrence of intestinal disturbances in these patients.

J Antibiot (Tokyo), 1998 Sep, 51(9), 845 - 51
3-amino-5-hydroxybenzoic acid in antibiotic biosynthesis . XI . Biological origins and semisynthesis of thionaphthomycins, and the structures of naphthomycins I and J; Hooper AM et al.; Fermentations of Streptomyces sp . E/784 produce low levels of the novel C-30 alkylthio-substituted ansamycin antibiotics naphthomycins J (9) and I (10), in addition to the more abundant C-30 hydroxylated analogues actamycin (1) and naphthomycin D (2) and C-30 chlorinated analogues naphthomycins H (3) and A (4) . The addition of N-acetyl-L-cysteine to the fermentation medium substantially increases the production of the thionaphthomycins J and I at the expense of their chloro analogues H and A . Other thiols and thiol progenitors are similarly utilised, including N-acetyl-L-cysteine methyl ester which affords the known naphthomycin F (8) and its novel 2-demethyl homologue (7) . The formation of thioansamycins from chloroansamycins and thiols in vivo is probably non-enzymic since similar conversions can be effected in vitro.

J Antibiot (Tokyo), 1998 Sep, 51(9), 837 - 44
Inhibition of fungal sphingolipid biosynthesis by rustmicin, galbonolide B and their new 21-hydroxy analogs; Harris GH et al.; The mode of action of the known antifungal macrolides rustmicin (1) and galbonolide B (2) has been determined to be the inhibition of sphingolipid biosynthesis . A large scale fermentation and isolation process was developed for production of large quantities of rustmicin . New 21-hydroxy derivatives of both compounds were isolated from pilot scale fermentations and were also produced by biotransformation of rustmicin and galbonolide B.

J Antibiot (Tokyo), 1998 Sep, 51(9), 823 - 8
Fattiviracin A1, a novel antiherpetic agent produced by Streptomyces microflavus Strain No . 2445 . I . Taxonomy, fermentation, isolation, physico-chemical properties and structure elucidation; Uyeda M et al.; A novel antiherpetic agent, fattiviracin A1, was isolated from the culture broth of strain No . 2445 identified as Streptomyces microflavus . It was purified through 1-butanol extraction, column chromatographies on Diaion HP-10 and silica gel and HPLC using a reverse phase column . The structure of fattiviracin A1 was determined by several spectroscopic experiments and chemical degradations . It is a new macrocyclic diester consisting of four D-glucose units and two (C24 and C33) hydroxy fatty acids . It is closely related to cycloviracins B1 and B2, but differs from these known compounds in both the length of its side chain and the sugar moiety.

J Infect, 1998 Jan, 36(1), 79 - 84
Antibodies to mycoplasma fermentans in HIV-positive heterosexual patients: seroprevalence and association with AIDS; Horowitz S et al.; There are conflicting reports concerning the prevalence of Mycoplasma fermentans in HIV-positive patients and its association with AIDS . Serum antibodies to M . fermentans were measured by a modified immunoblotting technique in 48 HIV-positive heterosexual patients and in 30 HIV-negative heterosexual controls . Antibodies to M . fermentans were detected in 19 (40%) of HIV-positive patients and in three (10%) of the HIV-negative controls (P = 0.01) . The prevalence of antibodies to Mycoplasma hominis and to Ureaplasma urealyticum was similar in both groups . In the HIV-positive group, 16/19 (84%) M . fermentans-positive patients developed AIDS, compared to eight of 29 (28%) M . fermentans-negative patients (P = 0.0004) . The HIV-positive patients with antibodies to M . fermentans had a lower CD4+ cell count and a higher prevalence of antibodies to the other mycoplasma tested (P = 0.007 and P = 0.03, respectively), as compared to the patients without antibodies to M . fermentans . These findings may suggest that the presence of antibodies to M . fermentans indicate an opportunistic infection . Of the 19 M . fermentans-positive patients, 11 were positive on the first examination, and eight became positive during the follow-up period . Seven out of these eight patients developed antibodies to M . fermentans before the development of AIDS . Therefore, the possibility exists that M . fermentans might influence the development of AIDS.

J Int Med Res, 1998 Aug-Sep, 26(4), 171 - 80
Red-wine polyphenols and inhibition of platelet aggregation: possible mechanisms, and potential use in health promotion and disease prevention; Halpern MJ et al.; An extract from red-wine grape fermentation, ANOX has been developed as a source of red-wine polyphenols, which are thought to inhibit several of the pathogenic pathways that lead to cardiovascular disease . New data indicate that this extract has a significantly greater effect than either red wine or red-wine powder on the inhibition of platelet aggregation in vitro . Based on this data, about 300 - 500 mg of the extract is equivalent to the daily dose of red-wine polyphenols that appears to protect against cardiovascular disease . The possible synergistic effect of red-wine polyphenols with vitamin C, their vasorelaxing activity and their possible role in preventing over-crosslinking of connective tissues (premature ageing) are considered . The extract contains standardized amounts of the whole spectrum of polyphenolic compounds found in red wine and may provide a valuable reference substance in clinical investigations of the physiological actions of plant polyphenols; its potential use in functional nutrition and preventive medicine is also discussed.

Am J Surg, 1998 Oct, 176(4), 384 - 9
The physiology of ileo-anal pouch function; Levitt MD et al.; Even excellent clinical function after ileo-anal pouch construction is associated with a variety of physiological abnormalities . Small bowel intestinal motility is essentially normal but the ileal reservoir serves to markedly suppress the ileal motor response both to progressive distension by intestinal contents and to transmitted myoelectrical complexes . As a result, the healthy pouch can accommodate a large volume of intestinal content before the rising baseline pressure and the appearance of large isolated contraction waves produce an urge to defecate . Evacuation in the normal pouch patient is rapid and highly efficient and is achieved by means of the Valsalva maneuver without any evidence of significant intestinal propulsion . External anal sphincter function is fully preserved but internal anal sphincter function is significantly impaired in the immediate postoperative period . Recovery occurs over the next 6 to 12 months but is often incomplete . Bacterial overgrowth in the pouch and prepouch ileum is almost universal and results in the premature deconjugation of primary bile salts and accumulation of secondary bile salts within the pouch . These produce morphologic changes in the ileal mucosa, and their excretion in pouch effluent gradually depletes the bile salt pool . Anerobic organisms also bind with vitamin B12 and the vitamin B12-intrinsic factor complex, resulting in subtle but measurable reductions in vitamin B12 levels in pouch patients . Finally, anerobic fermentation of mucus and undigested carbohydrate results in excessive quantities of short chain fatty acids within the pouch lumen . The clinical significance of these substances is unclear, but they may have an adverse action on both ileal mucosal and smooth muscle function . In essence, however, the pouch surgeon can maximize the likelihood of good clinical function by constructing a large capacity pouch, by avoiding surgery in patients with clearly deficient anal sphincter mechanisms, and by careful attention to pouch-anal anastomotic technique.

Arq Gastroenterol, 1998 Apr-Jun, 35(2), 132 - 7
Use of undiluted whole cow's milk is effective for the routine treatment of children with acute diarrhea and severe dehydration; Sperotto G et al.; A comparison is made between two groups of children aged 1-24 months and admitted to a teaching University Hospital due to acute diarrhea and severe dehydration . One group (n = 119) received a diluted cow's milk formula and the other (n = 109) a full-strength formula . Duration of diarrhea was similar: In the group that received full-strength milk weight gain was greater during diarrhea (5.03 vs . 1.80 g/kg/day, P < 0.01) and during the hospital stay (5.39 vs . 2.33 g/kg/day, P < 0.001) . Weight for height z-scores and weight for height as percentage of median improved during the hospital stay only in the group that received the full-strength formula . Full-strength cow's milk seems to be an adequate routine regimen even for children with acute diarrhea that must be treated for severe dehydration . In developing countries diarrhea and dehydration are a disease of small children . As rates of exclusive breast feeding are low, mainly in the urban setting, cow's milk is the main and sometimes the only food available . Lactose-free formulae are priced out of reach of the poor people and in Latin America there is no accepted tradition for use of fermented milk products . Our study is an indication that use of undiluted cow's milk may be effective for the routine treatment of acute diarrhea in children that must be treated as inpatients due to severe dehydration.

West Afr J Med, 1998 Jul-Sep, 17(3), 153 - 6
Effect of acute dietary fibre supplementation on colonic pH in healthy volunteers; Naaeder SB et al.; Dietary fibre and undigested starch are fermented to short chain fatty acids by colonic bacteria with acidification of the colon . It has been suggested that acidification of the colon by these fatty acids inhibits bacterial metabolism, but this concept has been disputed . The aim of this study was to investigate the short term effect of a dietary fibre load on colonic metabolism . Colonic pH and breath hydrogen was measured in healthy omnivorous British male volunteers following ingestion, in turn and at weekly intervals, of 15g lactulose, wheat bran biscuits, oat bran biscuits and ispaghula husk . All the test meals caused a reduction in caecal pH and an increase in breath hydrogen production . The changes were greatest with lactulose . Lactulose and wheat bran caused acidification of the right and left colon whereas oat bran and ispaghula husk caused acidification of mainly the right colon . An inverse correlation between right colonic pH and breath hydrogen was observed in only the oat bran study . This study has demonstrated the ability of dietary fibre to lower right colonic pH and to increase breath hydrogen excretion . The changes were greater with soluble fibre than with insoluble fibre but the change in luminal pH was persistent all round the colon with insoluble fibre.

J Wildl Dis, 1998 Oct, 34(4), 797 - 800
Duodenal volvulus in free-living green turtles from coastal United Arab Emirates; Hasbun CR et al.; Post-mortem examinations performed during May and August of 1997 on three free-living green turtles (Chelonia mydas) in the United Arab Emirates revealed that all had stomachs full of fresh seagrass (approximately 99% of the total ingesta) and presented with a duodenal volvulus involving a length of approximately 100 cm . Duodeni appeared empty and necrotic with diffuse purple-black mucosa . No apparent signs of obstruction by foreign objects, acute endoparasitism, or other disorders were observed . In all cases, duodenal volvulus was diagnosed, the cause of which may have been dietary in origin . The rise in water temperature, with an associated rise in the temperature of seagrass, thus enhancing the over-fermentation of ingesta with the subsequent liberation of excessive amounts of gas was the probable cause of volvulus formation . Ingestion of foreign bodies and physical movement also are discussed as causes of digestive disorders . It is recommended that handlers should avoid 360 degrees rotation when overturning turtles onto their carapaces.

Biochem Biophys Res Commun, 1998 Nov 9, 252(1), 29 - 33
Gpr1p, a putative G-protein coupled receptor, regulates glucose-dependent cellular cAMP level in yeast Saccharomyces cerevisiae; Yun CW et al.; How cells monitor the availability of nutrition and transduce signals is a fundamental, unanswered question . We have found that Gpr1p, a recently identified G-protein (Gpa2p) coupled receptor in yeast Saccharomyces cerevisiae, regulate the cellular cAMP level in response to glucose . The glucose-induced higher cAMP level found in the strain with GPA2 in multicopy plasmid decreased by deletion of GPR1 gene . A transient increase of cAMP in response to glucose was not observed in a Deltagpr1 mutant strain and this defect was complemented and restored by introducing GPR1 gene with YCp vector . Gpr1p was also required for the increase of cAMP in response to other fermentable sugars . Both membrane proximal regions o the third cytosolic loop in Gpr1p, which has been shown to be important for coupling to G-proteins, were also required for glucose-induced transient increase of cAMP . Our findings suggest that Gpr1p is part of the nutrition sensing machinery most likely acting as a receptor to monitor glucose as well as other fermentable sugars and regulate cellular cAMP levels .

J Biol Chem, 1998 Nov 20, 273(47), 31337 - 44
Mitochondrial respiratory mutants in yeast inhibit glycogen accumulation by blocking activation of glycogen synthase; Yang R et al.; Control of glycogen synthase activity by protein phosphorylation is important for regulating the synthesis of glycogen . In this report, we describe a regulatory linkage between the ability of yeast cells to respire and activation of glycogen synthase . Strains containing respiration-deficient mutations in genes such as COQ3, required for the synthesis of coenzyme Q, were reduced in their ability to accumulate glycogen in response to limiting glucose . This lowered glycogen accumulation results from inactivation of the rate-determining enzyme, glycogen synthase (Gsy2p) . Reduced glycogen synthase activity is coincident with lowered glucose 6-phosphate and ATP levels in the respiration-deficient cells deprived of glucose . Alanine substitutions of three previously characterized phosphorylation sites in Gsy2p, Ser-650, Ser-654, or Thr-667, each suppressed the glycogen defect in cells unable to respire, suggesting that inactivation of this enzyme is mediated by phosphorylation of these residues . Inactivation of glycogen synthase requires the RAS signaling pathway that controls cAMP-dependent protein kinase and is independent of Pho85p previously identified as a Gsy2p kinase . These results suggest that yeast cells unable to shift from a fermentative to a respiratory metabolic regimen block accumulation of glycogen by inactivating Gsy2p through protein phosphorylation.

Trends Biotechnol, 1998 Oct, 16(10), 419 - 27
Bacterial and other biological systems for polyester production; Steinbuchel A et al.; Poly(3-hydroxybutyric acid) and other structurally related aliphatic polyesters from bacteria, referred to as polyhydroxyalkanoic acids, form biodegradable thermoplastics and elastomers that are currently in use, or being considered for use, in industry, medicine, pharmacy and agriculture . At present, they are produced by microbial fermentations; in the future, production will also be possible by in vitro methods or by agriculture using transgenic plants . Representatives from this highly diverse class of polyesters might be produced as commodity chemicals for bulk applications, and others as fine chemicals for special applications.

J Biotechnol, 1998 Aug 27, 63(3), 187 - 98
Dielectric spectroscopy in the cultivation of suspended and immobilized hybridoma cells; Noll T et al.; Dielectric spectroscopy, also referred to as capacitance measurement, was evaluated as a tool for on-line and real-time monitoring of hybridoma cell growth in suspension batch culture and in immobilized cell culture in porous glass carriers . The capacitance signal proved to be a lumped parameter influenced by cell concentration, cell size and culture conditions . During a batch culture the cell specific capacitance signal changes by about 45% having a maximum value at the maximum growth rate . An excellent correlation between the specific capacitance and the specific amount of nucleotidetriphosphates in the cells could be shown . Dielectric spectroscopy proved to be a useful tool for on-line monitoring of cell attachment and growth in open porous microcarriers in fluidized bed fermenters . Also, in this system only an approximate correlation with viable cell concentration appeared, whereas an exact correlation with the glutamine consumption rate, a measure of the metabolic activity of the cells, could be shown . This allowed a closed loop control of the medium feed rate, which was directly linked to the capacitance signal during the entire course of a continuous fermentation.

Physiol Res, 1998, 47(4), 259 - 63
Age effect on in vitro fermentation pattern and methane production in the caeca of chickens; Marounek M et al.; Age-dependent changes of the caecal fermentation pattern were studied in female chickens using in vitro batch incubation technique . Chickens were sequentially killed at the age of 1, 2, 3 and 4 months, their caecal contents added to a broth with starch and incubated at 39 degrees C for 20 h . Net productions of short-chain fatty acids (SCFA), succinate, ethanol, lactate, methane, hydrogen and ammonia were determined . Methanogenesis was absent in caeca of 1-month-old chickens . Production of methane started in the second month and doubled in the third month of age . The start of methanogenesis was accompanied by changes of the fermentation stoichiometry . The production of succinate ceased and that of ethanol decreased to less than one tenth . There were no major changes of the caecal fermentation pattern in the fourth month of age . The ammonia production increased in the second month, indicating increased deamination activity . No major shifts in SCFA molar composition dependent on age were found . Calculated hydrogen recoveries suggest a decrease of reductive acetogenesis until 3 months of age . It can thus be concluded that age and the onset of methane production affect the fermentation pattern in the caeca of chickens.

Alcohol Clin Exp Res, 1998 Oct, 22(7), 1570 - 83
A review: acute and chronic effects of ethanol and alcoholic beverages on the pancreatic exocrine secretion in vivo and in vitro; Niebergall-Roth E et al.; Whereas oral or intraduodenal ethanol causes a moderate stimulation of pancreatic bicarbonate and enzyme output, intravenous ethanol inhibits basal and hormonally stimulated pancreatic exocrine secretion in humans, dogs, cats, pigs, rabbits, and rats . This inhibition could be mediated by inhibitory cholinergic mechanisms or be the result of a direct cellular effect of ethanol . In vitro investigations have specified several signaling molecules that may be involved in the action of ethanol on stimulus-secretion coupling in the exocrine pancreas, including cyclic adenosine monophosphate, intracellular calcium, and cholecystokinin and somatostatin receptors . In difference to pure ethanol solutions and distilled spirits, beer strongly stimulates pancreatic enzyme output, probably by nonalcoholic fermentation products . During chronic alcoholism, the ethanol-induced inhibition is replaced by an enhanced enzyme output that causes intraductal protein precipitation . In vitro investigations suggest that this increase is reversible after alcohol withdrawal . The occurrence of protein precipitates is considered to be a crucial step in the development of chronic alcoholic pancreatitis in humans . Other ethanol-induced secretory alterations that may contribute to the development of alcoholic pancreatitis are a decreased secretion of trypsin inhibitor, an increased cholinergic tone, and changes in the concentration of lithostathine.

Appl Microbiol Biotechnol, 1998 Sep, 50(3), 384 - 9
Degradation of cyanide in agroindustrial or industrial wastewater in an acidification reactor or in a single-step methane reactor by bacteria enriched from soil and peels of cassava; Siller H et al.; During cassava starch production, large amounts of cyanoglycosides were released and hydrolysed by plant-borne enzymes, leading to cyanide concentrations in the wastewater as high as 200 mg/l . For anaerobic degradation of the cyanide during pre-acidification or single-step methane fermentation, anaerobic cultures were enriched from soil residues of cassava roots and sewage sludge . In a pre-acidification reactor this culture was able to remove up to 4 g potassium cyanide/l of wastewater at a hydraulic retention time (tHR) of 4 days, equivalent to a maximal cyanide space loading of 400 mg CN- 1(-1) day-1 . The residual cyanide concentration was 0.2-0.5 mg/l . Concentrated cell suspensions of the mixed culture formed ammonia and formate in almost equimolar amounts from cyanide . Little formamide was generated by chemical decay . A concentration of up to 100 mmol ammonia/l had no inhibitory effect on cyanide degradation . The optimal pH for cyanide degradation was 6-7.5, the optimal temperature 25-37 degrees C . At a pH of 5 or lower, cyanide accumulated in the reactor and pre-acidification failed . The minimal tHR for continuous cyanide removal was 1.5 days . The enriched mixed culture was also able to degrade cyanide in purely mineralic wastewater from metal deburring, either in a pre-acidification reactor with a two-step process or in a one-step methanogenic reactor . It was necessary to supplement the wastewater with a carbon source (e.g . starch) to keep the population active enough to cope with any possible inhibiting effect of cyanide.

Appl Microbiol Biotechnol, 1998 Sep, 50(3), 379 - 83
The formation of 1-hydroxymethylnaphthalene and 6-hydroxymethylquinoline by both oxidative and reductive routes in Cunninghamella elegans; Mountfield RJ et al.; Extraction of medium after incubation of the fungus, Cunninghamella elegans, with 0.03% (w/v) 1-methylnaphthalene produced mainly 1-hydroxymethylnaphthalene together with some 1-naphthoic acid and hydroxynaphthoic acid . Higher concentrations of substrate were inhibitory to biotransformation . Similar incubations with 1-naphtoic acid as substrate resulted in reduction of the carboxyl group to give 1-hydroxymethylnaphthalene . When 6-methylquinoline was used, the main product was 6-hydroxymethylquinoline but also some quinoline-6-carboxylic acid and some 6-methylquinoline-N-oxide were identified . In a 2-l fermenter 2.5 g substrate was transformed in 324 h . The 6-hydroxymethylquinoline was also produced by reduction of quinoline-6-carboxylic acid by the organism.

Appl Microbiol Biotechnol, 1998 Sep, 50(3), 299 - 302
An enzyme-linked immunosorbent assay for the estimation of fungal biomass during solid-state fermentation; Dubey AK et al.; An enzyme-linked immunosorbent assay for sensitive, specific and quantitative estimation of fungal biomass during solid-state fermentation is described . Using this method, differential growth rates and colonization of the substrate can be studied . The assay has potential application for the efficient monitoring of solid-state fermentation involving specific fungus, for which available methods are not adequate.

Antonie Van Leeuwenhoek, 1998 Apr, 73(3), 263 - 9
Genetic and fermentation properties of the K2 killer yeast, Saccharomyces cerevisiae T206; Franken DB et al.; Saccharomyces cerevisiae T206 K+R+, a K2 killer yeast, was differentiated from other NCYC killer strains of S . cerevisiae on the basis of CHEF-karyotyping and mycoviral RNA separations . Genomic DNA of strain T206 was resolved into 13 chromosome bands, ranging from approximately 0.2 to 2.2 Mb . The resident virus in strain T206 yielded L and M RNA species of approximately 5.1 kb and 2.0 kb, respectively . In micro-scale vinifications, strain T206 showed a lethal effect on a K-R- mesophilic wine yeast . Metabolite accumulation and toxin activity were measured over a narrow pH range of 3.2 to 3.5 . Contrary to known fermentation trends, the challenged fermentations were neither stuck nor protracted although over 70% of the cell population was killed . Toxin-sensitive cells showed cytosolic efflux.

Curr Genet, 1998 Oct, 34(4), 287 - 96
Azf1p is a nuclear-localized zinc-finger protein that is preferentially expressed under non-fermentative growth conditions in Saccharomyces cerevisiae; Stein T et al.; In previous studies the AZF1 gene has been identified as a second high-copy number suppressor for a special mutant of the gene for the mitochondrial core enzyme of RNA polymerase . The first high-copy number suppressor of this mutant turned out to be the specificity factor MTF1 for mitochondrial transcription . Up to now, the influence of AZF1 on mitochondrial transcription, its precise localization in the cell and the regulation of its expression has not been determined . The putative protein contains a long stretch of poly-asparagine amino acids and a typical zinc-finger domain for DNA binding . These characteristic structural features were used to create the abbreviation AZF1 (Asparagine-rich Zinc Finger protein) . An initial computer analysis of the sequence gave no conclusive results for the presence of a mitochondrial import sequence or a typical nuclear-targeting sequence . A recent more-detailed analysis identified a possible nuclear localization signal in the middle of the protein . Disruption of the gene shows no effect on plates with glucose-rich medium or glycerol . In this report a specific polyclonal antibody against Azf1p was prepared and used in cell-fractionation experiments and in electron-microscopic studies . Both of these clearly demonstrate that the AZF1 protein is localized exclusively in the nucleus of the yeast cell . Northern analysis for the expression of the AZF1 messenger RNA under different growth conditions was therefore performed to obtain new insights into the regulation of this gene . Together with the respective protein-expression analysis these data demonstrate that Azf1p is preferentially synthezised in higher amounts under non-fermentable growth conditions . Over-expression of Azf1p in the yeast cell does not influence the expression level of the mitochondrial transcription factor Mtf1p, indicating that the influence of Azf1p on the suppression of the special mitochondrial RNA polymerase mutant is an indirect one . Subcellular investigation of the deletion mutant by electron microscopy identifies specific ultrastructural cell-division defects in comparison to the wild-type.

Biosci Rep, 1998 Jun, 18(3), 143 - 54
Relationship of the Escherichia coli TrkA system of potassium ion uptake with the F0F1-ATPase under growth conditions without anaerobic or aerobic respiration; Trchounian A et al.; K+ uptake by the Escherichia coli TrkA system is unusual in that it requires both ATP and deltamuH+; a relation with H+ circulation through the membrane is therefore suggested . The relationship of this system with the F0F1-ATPase was studied in intact cells grown under different conditions . A significant increase of the N,N'-dicyclohexylcarbodiimide(DCCD)-inhibited H+ efflux through the F0F1 by 5 mM K+, but not by Na+ added into the potassium-free medium was revealed only in fermenting wild-type or parent cells, that were grown under anaerobic conditions without anaerobic or aerobic respiration and with the production of H2 . Such an increase disappeared in the deltaunc or the trkA mutants that have altered F0F1 or defective TrkA, respectively . This finding indicates a closed relationship between TrkA and F0F1, with these transport systems being associated in a single mechanism that functions as an ATP-driven H(+)-K(+)-exchanging pump . A DCCD-inhibited H(+)-L(+)-exchange through these systems with the fixed stoichiometry of H+ and K+ fluxes (2H+/K+) and a higher K+ gradient between the cytoplasm and the external medium were also found in these bacteria . They were not observed in cells cultured under anaerobic conditions in the presence of nitrate or under aerobic conditions with respiration and without production of H2 . The role of anaerobic or aerobic respiration as a determinant of the relationship of the TrkA with the F0F1 is postulated . Moreover, an increase of DCCD-inhibited H+ efflux by added K+, as well as the characteristics of DCCD-sensitive H(+)-K(+)-exchange found in a parent strain, were lost in the arcA mutant with a defective Arc system, suggesting a repression of enzymes in respiratory pathways . In addition, K+ influx in the latest mutant was not markedly changed by valinomycin or with temperature . The arcA gene product or the Arc system is proposed to be implicated in the regulation of the relationship between TrkA and F0F1.

Protein Expr Purif, 1998 Nov, 14(2), 160 - 6
High-level expression of eukaryotic polypeptides from bacterial chromosomes; Olson P et al.; Attractive economics and short development timelines have often been cited as reasons for using bacteria to express eukaryotic proteins on a commercial scale . Nevertheless, routine techniques for bacterial expression of heterologous proteins are beset by a variety of technical and legal difficulties . In particular, the use of plasmids to express foreign proteins, popular promoter systems, protein fusion partners, and histidine tags and the recovery of proteins from inclusion bodies are affected by a host of issued patents . Chromosomally encoded leaderless fusions (CELF) offer a variety of technical and legal advantages over existing bacterial expression systems . In this study, we show that CELF can be used to produce a wide assortment of eukaryotic proteins at 10-liter fermentation scale .

J Natl Cancer Inst, 1998 Oct 21, 90(20), 1559 - 63
The chondramides: cytostatic agents from myxobacteria acting on the actin cytoskeleton; Sasse F et al.; BACKGROUND: Chondramides are cyclodepsipeptides produced by strains of the myxobacterium, Chondromyces crocatus . These peptides, which have been reported to inhibit yeast and mammalian cell proliferation, are related to jasplakinolide, which has been isolated from marine sponges of the genus Jaspis and has been shown to interfere with the actin cytoskeleton (a structural component of cells that helps maintain their shape and is involved in processes, such as cell division and cell locomotion) . We studied the effects of the chondramides (A, B, C, and D) on tumor cell growth, on cytoskeletal structure, and on actin polymerization in vitro and compared these effects with those of cytochalasin D and jasplakinolide . METHODS: Cell proliferation was measured by means of tetrazolium salt reduction assays . Effects on the cytoskeleton were studied by use of fluorescence techniques, and actin polymerization in vitro was measured by means of viscosimetry . RESULTS: Proliferation of tested tumor cell lines was inhibited by the chondramides . Concentrations that inhibited proliferation by 50% (IC50 values) ranged from 3 to 85 nM and were of the same order of magnitude as those found for cytochalasin D and jasplakinolide . Fluorescence staining of potoroo cells incubated with chondramides A and B showed that organization of the actin cytoskeleton was disrupted; however, the microtubule system was not affected . Viscosimetric measurement showed that, depending on the experimental conditions, chondramide A induced or accelerated actin polymerization in vitro . CONCLUSION: The chondramides--unlike jasplakinolide--can be produced in large amounts by fermentation, and, similar to jasplakinolide, they appear to have antiproliferative activity against carcinoma cell lines by targeting the actin cytoskeleton.

J Dairy Sci, 1998 Sep, 81(9), 2451 - 8
Influence of soybean oil in high fiber diets fed to nonlactating cows on ruminal unsaturated fatty acids and nutrient digestibility; Bateman HG 2nd et al.; An experiment with a 5 x 5 Latin square design was conducted to determine the effects of the addition of soybean oil to high fiber diets on ruminal fermentation and ruminal lipid concentrations . Diets were 50% bermudagrass hay and 50% concentrate . Soybean oil was added to diets at 0, 2, 4, 6, or 8% of the dietary dry matter (DM) . Ruminal samples were collected every 2 h on the last day of each period and analyzed for volatile fatty acids and lipids . The addition of soybean oil decreased DM and organic matter intake but increased fatty acid intake . Soybean oil had no effect on total tract digestibility of DM, organic matter, N, or neutral detergent fiber but decreased digestibility of fatty acids . The addition of soybean oil decreased total volatile fatty acid concentrations and the acetate to propionate ratio . Ruminal concentrations of unsaturated free fatty acids increased nonlinearly as soybean oil in the diets increased but remained < 0.67 mg/g of DM or 3% of the total fatty acids . Ruminal concentrations of total fatty acids and total saturated fatty acids increased nonlinearly as soybean oil in the diets increased . Total unsaturated fatty acid concentrations increased linearly as soybean oil increased . Neutral lipid concentrations in the rumen did not respond to increased soybean oil . These data indicate that large amounts of soybean oil can be fed in high fiber diets without greatly increasing the concentration of ruminal unsaturated fatty acids or depressing nutrient digestibility.

Nutrition, 1998 Oct, 14(10), 763 - 6
Complementary feeding: a global perspective; Michaelsen KF et al.; The growth of children in developing countries often declines with the introduction of complementary foods around the age of 6 mo and continues to decline up to 18 mo . These growth deficits are accompanied by delayed development and increased morbidity and mortality . The main cause is nutritionally inadequate and often contaminated complementary foods that typically consist of a cereal-based porridge, with little vegetables and no animal products . Such a diet is bulky, has a low nutrient density and a high content of antinutrients . Promotion of traditional household technologies such as germination and fermentation may be affordable measures to improve the complementary foods . Germination serves to reduce the bulkiness and thus increase the energy and nutrient density . Fermentation leads to hydrolysis of antinutrient phytates and hence increased bioavailability of minerals, and may also have beneficial effects on susceptibility to diarrhea . Alternative strategies include addition of vitamin C-rich foods and meat that enhance absorption of minerals, or direct enrichment of energy and nutrients by addition of animal products, such as fat, fish, meat or milk, vegetables or fruits, or a micronutrient mix.

Nutrition, 1998 Oct, 14(10), 758 - 62
Nutritional management of acute diarrhea; Sullivan PB; Despite recommendations from several bodies such as the World Health Organization and others that feeding should be continued during diarrhea, the practice of withholding food during the early stages of diarrhea is still widespread . This contributes to a deterioration in patients' nutritional state . The principal controversy in the nutritional therapy of acute gastroenteritis centers on the relative risks of cows'-milk feeds . The two things that need to be considered in determining the optimum approach to feeding the child with acute diarrhea are the optimum timing for feeding children in relation to the onset of and recovery from symptoms and, secondly, the effects of specific food ingredients in the diet . Recent studies have demonstrated that the vast majority of young children with acute diarrhea can be successfully managed with continued feeding of undiluted non-human milk . Routine dilution of milk and routine use of lactose-free formula are not necessary, especially when oral rehydration therapy and early feeding (in addition to milk) form the basic approach to the clinical management of diarrhea in children . Confounding factors are the severity of the diarrhea, coexistent malnutrition, and young age (< 1 y); such infants are much more likely to have complications from early feeding with undiluted milk and some would advocate use of specifically designed lactose-free formula in such children . Children who are fed exclusively with human milk and those who receive solid foods with or without human milk may safely continue to receive their usual diets during diarrhea . Those who are fed exclusively with non-human milk--especially when very young and with severe diarrhea or malnutrition--should be closely observed if they continue to consume milk or they should receive a special formulation (e.g., a cereal-milk mixture or fermented milk product) . The use of nutrient-dense mixtures of common foods may be advisable to promote compensatory growth in those who lose weight during illness or because of anorexia or malabsorption.

J Dairy Sci, 1998 Sep, 81(9), 2430 - 9
Effect of amount of dietary supplement and source of protein on milk production, ruminal fermentation, and nutrient flows in dairy cows; O'Mara FP et al.; An experiment with a multiple Latin square design using 36 midlactation Friesian cows was carried out to determine the effect of fish meal or soybean meal in a supplement fed at two amounts (3.5 or 7 kg/d) with grass silage . The diets were also fed to four ruminally and duodenally cannulated cows to determine digestibility, ruminal fermentation, and nutrient flows . Dry matter intake, milk production, milk constituent yields, and concentrations of protein and lactose were significantly increased by the supplements when provided at 7 kg/d . The supplement containing fish meal increased milk production, protein and lactose yields, and milk protein concentration, but the increases were smaller than those obtained by increasing the amount of supplement fed . Neither the type nor the amount of supplement fed affected digestibility of dry matter or organic matter, and few significant effects on ruminal fermentation were observed . Supplements fed at the higher allowance significantly increased the flow of dry matter, organic matter, all nitrogenous components, and amino acids to the duodenum . The supplement containing fish meal significantly increased the duodenal flow of nonammonia nonmicrobial N and some amino acids . Results indicated that an increase in the concentration of supplement in the diet is more effective in increasing milk production, protein concentration and yield, and flow of amino acids to the duodenum than is increasing the concentration of ruminally undegradable protein in the supplement.

J Invertebr Pathol, 1998 Nov, 72(3), 319 - 22
Toxicity of purified fungal toxin hirsutellin A to the citrus rust mite phyllocoptruta oleivora (Ash.)
Omoto C, McCoy CW.
A toxic protein, hirsutellin A, isolated from culture filtrate during liquid fermentation of the fungal mycelia of Hirsutella thompsonii, was tested using contact/residual and residual leaf bioassay methodologies at concentrations of 0, 10, 32, 56, and 100 &mgr;g/ml against adult citrus rust mite, Phyllocoptruta oleivora . P . oleivora is the natural host of the parasitic fungus, H . thompsonii . Mite mortality increased with an increase in hirsutellin A concentration, reaching virtually 100% at 100 &mgr;g/ml using both leaf assay methods . The number of eggs found on leaf disk bioassays within a 3-day period decreased significantly with an increase in hirsutellin A concentration, suggesting that fecundity was affected prior to the death of the host .

Extremophiles, 1998 Aug, 2(3), 223 - 8
Analysis of intracellular pH in the yeast Saccharomyces cerevisiae under elevated hydrostatic pressure: a study in baro- (piezo-) physiology; Abe F et al.; Hydrostatic pressure is a distinctive feature of deep-sea environments, and this thermodynamic parameter has potentially inhibitory effects on organisms adapted to living at atmospheric pressure . In the yeast Saccharomyces cerevisiae, hydrostatic pressure causes a delay in or cessation of growth . The vacuole is a large acidic organelle involved in degradation of cellular proteins or storage of ions and various metabolites . Vacuolar pH, as determined using the pH-sensitive fluorescent dye 6-carboxyfluorescein, was analyzed in a hydrostatic chamber with transparent windows under elevated hydrostatic pressure conditions . A pressure of 40-60 MPa transiently reduced the vacuolar pH by approximately 0.33 . A vma3 mutant defective in vacuolar acidification showed no reduction of vacuolar pH after application of hydrostatic pressure, indicating that the transient acidification is mediated through the function of vacuolar H(+)-ATPase . The vacuolar acidification was observed only in the presence of fermentable sugars, and never observed in the presence of ethanol, glycerol, or 3-o-methyl-glucose as the carbon source . Analysis of a glycolysis-defective mutant suggested that glycolysis or CO2 production is involved in the pressure-induced acidification . Hydration and ionization of CO2 is facilitated by elevated hydrostatic pressure because a negative volume change (delta V < 0) accompanies the chemical reaction . Moreover the glucose-induced cytoplasmic alkalization is inhibited by elevated hydrostatic pressure, probably because of inhibition of the plasma membrane H(+)-ATPase . Therefore, the cytoplasm tends to become acidic under elevated hydrostatic pressure conditions, and this could be crucial for cell survival . To maintain a favorable cytoplasmic pH, the yeast vacuoles may serve as proton sequestrants under hydrostatic pressure . We are investigating the physiological effects of hydrostatic pressure in the course of research in a new experimental field, baro-(piezo-) physiology.

Indian J Exp Biol, 1998 Jul, 36(7), 688 - 92
Optimisation of different physical parameters for bioleaching of phosphate by Aspergillus niger from Indian rock phosphate; Ghosh R et al.; A mutant strain of Aspergillus niger AB100 was incubated with samples of rock phosphate . Mutation resulted in a greater amount of solubilisation (30 to 35%) as against the parent strain (10 to 15%) . The influence of leaching parameters such as ore concentration (pulp density), particle size, initial pH of the medium, temperature, volume of the medium in 250 ml flasks, inoculum concentration and age of inoculum was studied . When low quantity of rock phosphate is applied (0.1%) the solubilisation of phosphorus was optimal (40.5%) . Optimum particle size was--200 to 240 mesh, initial pH of the medium 4.0, optimum volume of the fermentation medium 160 ml, time period of incubation was 8 days, inoculum volume was 7.5 ml, and age of inoculum 7 days . The maximum leaching of phosphorus by using these optimum physical parameters is 45 to 50%.

Adv Exp Med Biol, 1998, 439, 117 - 29
Differentiation of soy sauce types by HPLC profile pattern recognition . Isolation of novel isoflavones; Kinoshita E et al.; Nonvolatile minor components in various brands of Japanese fermented soy sauce were analyzed by gradient RP-HPLC and monitored at 280 nm . Chemometric pattern recognition techniques, such as cluster analysis, linear discriminant analysis (LDA), LDA using genetic algorithm (GA-LDA) and soft independent modelling of class analogy (SIMCA), succeeded in differentiating the resulting HPLC profiles according to soy sauce brands . Three components playing key roles in the differentiation were isolated by preparative HPLC and purified by gel-filtration chromatography, or simply repeated preparative HPLC . FAB-MS, 1H-, 13C-NMR and IR spectra suggested that these three components having molecular weights of 386, 402 and 418 were isoflavone derivatives . By applying HMBC spectral analysis, these isoflavones were identified as conjugated ethers of tartaric acid with daidzein, genistein and 8-hydroxygenistein . These new isoflavone derivatives are produced by some strains of Aspergillus fungi.

Yeast, 1998 Sep 15, 14(12), 1089 - 104
Transient mRNA responses in chemostat cultures as a method of defining putative regulatory elements: application to genes involved in Saccharomyces cerevisiae acetyl-coenzyme A metabolism; van den Berg MA et al.; To identify common regulatory sequences in the promoters of genes, transcription of 31 genes of Saccharomyces cerevisiae was analysed during the transient response to a glucose pulse in a chemostat culture . mRNA levels were monitored during the subsequent excess glucose, ethanol and acetate phases, while other conditions were kept constant . This setup allowed a direct comparison between regulation by glucose, ethanol and acetate . Genes with identical regulation patterns were grouped to identify regulatory elements in the promoters . In respect to regulation on glucose four classes were identified: no transcription under any of the conditions tested, no difference in regulation on glucose, induced on glucose and repressed on glucose . In addition, genes were found that were repressed or induced on ethanol or acetate . Sequence alignment of genes with similar regulation patterns revealed five new, putative regulatory promoter elements . (i) The glucose-inducible fermentation genes PDC1 and ADH1 share the sequence ATACCTTCSTT . (ii) Acetate-repression might be mediated by the decamer CCCGAG RGGA, present in the promoters of ACS2 and ACR1 . (iii) A specific element (CCWTTSRNCCG) for the glyoxylate cycle was present in seven genes studied: CIT2, ICL1, MLS1, MDH2, CAT2, ACR1 and ACH1 . These genes were derepressed on ethanol or acetate . (iv) The sequence ACGTSCRGAATGA was found in the promoters of the partially ethanol-repressed genes ACS1 and YAT1 . (v) Ethanol induction, as seen for ACS2, ADH3 and MDH1, might be mediated via the sequence CGGSGCCGRAG.

Mol Cell Probes, 1998 Oct, 12(5), 301 - 8
Multiplex PCR for the detection of Mycoplasma fermentans, M . hominis and M . penetrans in cell cultures and blood samples of patients with chronic fatigue syndrome; Choppa PC et al.; A multiplex polymerase chain reaction (PCR) was initially developed to detect the presence of mycoplasma genus DNA sequences in cell cultures and to differentiate between three human pathogenic mycoplasma species simultaneously . The assay in turn, proved to be a useful tool for the detection of mycoplasma infection in human DNA samples . One set of oligonucleotide primers which are specific for a highly conserved region among all members of the genus mycoplasma along with three other primer sets which are specific for Mycoplasma fermentans, Mycoplasma hominis andMycoplasma penetrans species were used in this assay . The sensitivity of detection was determined by infecting peripheral blood mononuclear cells (PBMC) of healthy individuals with known bacterial copy numbers from each species, extracting the DNA, and subjecting 1 microgram of DNA from each sample to 40 cycles of amplification . By using agarose gel electrophoresis the detection level was determined to be 7, 7, 9 and 15 mycoplasma cells per microgram of human genomic DNA for M . genus,M . fermentans, M . hominis and M . penetrans, respectively . The assay was applied to DNA extracted from the PBMCs of individuals suffering from chronic fatigue syndrome (CFS) (n=100) as determined by the Center for Disease Control (CDC) criteria, and compared to healthy individuals (n=100) . The percentage of M . genus infection was found to be 52% in CFS patients and only 15% in healthy individuals.Mycoplasma fermentans, M . hominis andM . penetrans were detected in 32, 9 and 6% of the CFS patients while they were detected in 8, 3 and 2% of the healthy control subjects, respectively . This assay provides a rapid and cost efficient procedure to screen either cell cultures or clinical samples for the presence of three potentially pathogenic species of mycoplasma with a high level of sensitivity and specificity .

Int J Biol Macromol, 1998 Oct, 23(3), 215 - 25
Thermal denaturation and renaturation of a fermentation broth of xanthan: rheological consequences; Capron I et al.; The rheological properties of an unpasteurised and concentrated xanthan fermentation broth (c = 30 g/l 0.02 M in salt) were studied before heat treatment and after a thermal heating/cooling cycle performed at various polymer concentration conditions (10-30 g/l) . At concentrations below 10 g/l heat denaturation occurs with dissociation of the native double-stranded structure into two single strands . At higher concentration, no complete dissociation happens . Changes in both viscoelastic properties and molecular weight are observed after heating above the melting order-disorder temperature (Tm) . They are related to the order disorder conformational transition of the xanthan molecules . Xanthan renatured in concentrated conditions (above 10 g/l) has a higher viscosity than that of the native sample and displays more gel-like properties . The inhibition of the dissociation in two single strands in the high concentration range is attributed to the presence of nematic phases observed by viscoelastic measurements and apolar microdomains evidenced by the addition of a neutral detergent.

Trends Biotechnol, 1998 Sep, 16(9), 369 - 73
Microgravity and its implication for fermentation biotechnology; Klaus DM; Fermentation processes are highly dependent upon physical and chemical environmental parameters, many of which are influenced by gravity . Extending biotechnology into the realm of space flight provides researchers with an opportunity to investigate the role that gravity plays in natural growth processes . Physical factors governing cell sedimentation, nutrient mixing and byproduct dispersion are altered in the absence of the constant sedimenting force of gravity . In addition, space flight has also been shown to give rise to a wide variety of indirect consequences associated with the physiology of the organisms themselves.

Comp Biochem Physiol A Mol Integr Physiol, 1998 Apr, 119(4), 925 - 30
Activity of cellulolytic enzymes in the contents of reticulorumen and caecocolon of roe deer (Capreolus capreolus); Deutsch A et al.; Selective ruminants, which prefer easily digestible plants, cannot digest fibrous forage as well as grass eaters . Low enzyme activity or short retention time of ingesta particles in fermentation chambers appeared to be responsible for reduced cellulose breakdown . Seasonal activity of cellulolytic enzymes, cellulose concentration and protozoa population in reticulorumen (RR) and caecocolon (CC) of roe deer as a typical concentrate selector were investigated . Cellulase activities were lowest in winter when cellulose concentration in RR contents were highest . Highest enzyme activities and lowest cellulose concentration were measured in early spring . Cellulolytic activities were significantly correlated with the number of protozoa in RR . Only one entodinomorphic genus was identified in the RR . The enzyme activities in CC were far lower compared with those in RR . Low cellulose digestion in the RR cannot be compensated for by cellulose breakdown in the CC . The reduced cellulose digestion of roe deer may be attributed to the short retention time of food particles in spring and summer, whereas decreased colonisation of microorganisms in the rumen may be the main reason for low cellulose breakdown in winter.

J Nutr, 1998 Oct, 128(10), 1786 - 93
Fermentable dietary fiber increases GLP-1 secretion and improves glucose homeostasis despite increased intestinal glucose transport capacity in healthy dogs; Massimino SP et al.; Ileal proglucagon gene expression and postprandial plasma concentrations of proglucagon-derived peptides are reported to change with the type and quantity of dietary fiber ingested by rats . Within the intestine, proglucagon encodes several proglucagon-derived peptides known to modulate intestinal absorption capacity and pancreatic insulin secretion . To determine whether the chronic ingestion of fermentable dietary fiber regulates the expression and synthesis of proglucagon-derived peptides in the distal intestine to modulate glucose homeostasis, the following study was conducted: 16 adult dogs (23 +/- 2 kg) were fed isoenergetic, isonitrogenous diets containing a mixture of high fermentable dietary fibers (HFF) or low fermentable (LFF) wood cellulose for 14 d in a randomized cross-over design . Food was withheld for 16 h before an oral glucose tolerance test was conducted supplying 2 g of glucose/kg body wt, and peripheral blood was collected via a hind-leg catheter at 0, 15, 30, 45, 60, 90 and 120 min for plasma glucose, insulin and glucagon-like peptide-1(7-36)NH2 (GLP-1) analyses . Intestinal samples were collected after the second dietary treatment . Ileal proglucagon mRNA, intestinal (GLP-1) concentrations and the integrated area under the curves (AUC) for plasma GLP-1 and insulin were greater and plasma glucose AUC was reduced when dogs were fed the HFF diet compared to the LFF diet (P < 0.05) . Intestinal villi heights, brush border and basolateral glucose transporter protein abundance and jejunal transport capacities were significantly greater when dogs were fed the HFF diet than when fed the LFF diet . In conclusion, improvements in glucose homeostasis are observed in healthy dogs when they ingest fermentable fibers.

J Nutr, 1998 Oct, 128(10), 1737 - 44
Confirmation of the role of rapidly fermentable carbohydrates in the expression of swine dysentery in pigs after experimental infection; Pluske JR et al.; Two experiments were conducted to test the hypothesis that soluble non-starch polysaccharides (NSP) and resistant starch (RS) cause swine dysentery (SD) in pigs experimentally infected with the spirochete Serpulina hyodysenteriae . In Experiment 1, a source of soluble NSP (guar gum; GG), insoluble NSP (oat chaff; OC), resistant starch (retrograde cornstarch; RS) or a combination of GG and RS (GG + RS) was added to a diet containing cooked white rice (R), soybean meal (SBM) and animal protein (meat and bone meal, bloodmeal, fishmeal) . A diet containing only cooked white rice, SBM and the sources of animal protein (AP) was also fed . In Experiment 2, three rice-based diets containing different levels of RS were fed to pigs . In Experiment 1, the pH of digesta in the cecum, proximal colon and distal colon of pigs fed diets R-GG, R-RS and R-GG + RS was lower (P < 0.001), and volatile fatty acid concentration higher (P < 0.001), than in pigs fed diets R-OC and R-AP . Pigs fed diets with RS and GG + RS had greater (P < 0.05) concentrations of ATP in the large intestine than pigs fed other diets . There were no significant differences in any fermentation indices measured in Experiment 2 . In Experiment 1, pigs fed diets R-GG, R-RS and R-GG + RS were colonized with S . hyodysenteriae after experimental infection . However, only pigs consuming diets R-GG (4 of 5) and R-GG + RS (5 of 5) showed clinical signs of SD . Spirochetes were isolated from the feces of all pigs fed diets containing RS in Experiment 2 . However, and in contrast to Experiment 1, 80-100% of pigs infected with S . hyodysenteriae displayed clinical signs of SD . These data confirm the role of fermentable carbohydrate in the pathogenesis of SD.

Am J Clin Nutr, 1998 Oct, 68(4), 802 - 19
Energy balance and thermogenesis in rats consuming nonstarch polysaccharides of various fermentabilities; Smith T et al.; BACKGROUND: The equivalents of dietary protein, fat, and available carbohydrate as fuels for maintenance (kJ apparent metabolizable energy/kJ maintenance requirement) are known from classical experiments and are similar across species; that for nonstarch polysaccharide (NSP) is undetermined . OBJECTIVES: Our objectives were to determine the energy equivalent of NSP and the thermic responses to NSP . DESIGN: In a randomized block design, 120 rats were treated in groups of 10 for 28 d with a basal diet (control) supplemented with starch and 10 different NSP treatments in amounts between 38 and 92 g/kg basal diet . Cellulose and starch were references . Thermic responses, deduced from body-composition changes and modeling of energy disposition, and energy and substrate excretion were determined . RESULTS: NSP had fermentabilities between 0.01 and 0.93 g/g intake . Fermentability, partial digestible energy, and net metabolizable energy values of NSP were closely related . Generally, 51% of apparent metabolizable energy from NSP (fermentable gross energy) met maintenance requirements . Diet (energy)-induced thermogenesis (DIT) was evident from whole diets . Fermentable NSP supplied net metabolizable energy and caused DIT . After DIT and fermentation were accounted for, NSP-induced thermogenesis was generally -2+/-4% (x+/-SEM) of gross NSP energy, except for an outlying pectic preparation, which was 33% (P< 0.1) . CONCLUSIONS: The energy equivalent of NSP was 196 (100/51) kJ/kJ, compared with 128, 105, and 100 for protein, fat, and glucose, respectively, from the classical experiments . With the exception of pectic NSP, NSP does not induce thermogenesis in excess of that associated with DIT and fermentation.

Br J Nutr, 1998 Jun, 79(6), 519 - 25
The use of cumulative gas and volatile fatty acid production to predict in vitro fermentation kinetics of Italian ryegrass leaf cell walls and contents at various time intervals; Groot JC et al.; Differences between the fermentation characteristics of cell contents (CC) and protease-treated cell walls (CW) of young leaves of Italian ryegrass (Lolium multiflorum Lam.) cultivar Multimo (tetraploid), were studied in vitro . Gas and volatile fatty acid (VFA) production rates were measured at regular intervals, as was the degradability of organic matter (OM) of CW . The measured VFA were used to predict the gas production and fermentable OM using stoichiometric calculations . For CW the volume and kinetics of measured gas production were the same as those predicted from the VFA formed . In contrast, the measured gas production for CC was consistently less than predicted, indicating that the stoichiometric equations were not valid for rapidly fermenting substrates . For both CC and CW, the relative rate of acetic acid production levelled off more slowly than for other VFA, resulting in an increasing gas yield (in ml/g fermentable OM) after 12 (CW)-24 (CC) h incubation . Consequently, the fermentation of OM was not linearly related to gas production kinetics . For CW, the kinetics of decline of degradable OM and fermentable OM were the same, after correction for a constant 'lost fraction' of degradable OM of 205 g/kg OM . This work indicates the value of detailed studies of fermentation processes to evaluate herbage quality . In particular, the role of CC and the difference between degradation and fermentation require further attention.

Indian J Med Sci, 1998 Feb, 52(2), 70 - 7
Ayurveda's role in preventing disease; Svoboda RE; Modern medical science is currently in the throes of a revolution which is likely to have a dramatic impact on both the theory of medicine and the way it is practised . The mechanistic model which served biomedicine well for many years is gradually collapsing, thanks to the efforts of dedicated researchers who have looked beyond that model's flaws . Thus we now know that networks of chemical communication exist between the nervous and immune systems, and that prayer at a distance can positively affect the conditions of those who are seriously ill, even when the prayer and the patient are not known to one another . Another participant in this exciting climate of change and ferment is Ayurveda, India's ancient medical system . While Ayurveda has already contributed much to modern medicine (reserpine, gugulipid, plastic surgery), its real contributions are yet to be made . While some of these are likely to come in matters of materia medica and technique, most will likely be derived from Ayurveda's way of seeing the world, its "darshana." This paper outlines a few of the ways in which Ayurveda's "vision" is likely to facilitate medicine's ability to teach people not just how to avoid disease but how to proactively develop and maintain a healthy "state."

Anesteziol Reanimatol, 1998 Jul-Aug, (4), 52 - 6
{The evaluation of the efficacy of preventing postoperative pancreatitis in stomach cancer patients by using izoptin and a prolonged peridural lidocaine block}; Kursov SV et al.; Efficacy of postoperative pancreatitis prevention is assessed in 123 patients with gastric cancer . Pancreatic bloodflow and central hemodynamics were assessed by rheography, activities of serum amylase and free-radical oxidation by biochemiluminescence of blood plasma . After radical surgery on the stomach, disorders of hemocirculation develop in the pancreas, leading to ischemia of the organ and formation of venous congestion; free-radical oxidation is activated and fermenturia increases . Prolonged epidural blocking with lidocaine prevented a decrease of arterial inflow to the pancreas, decreased the intensity of free-radical oxidation, and was more effective than isoptin therapy.

J Antibiot (Tokyo), 1998 Aug, 51(8), 795 - 800
Conversion of spinosyn A and spinosyn D to their respective 9- and 17-pseudoaglycones and their aglycones; Creemer LC et al.; Forosamine at the 17-position of spinosyns A and D was hydrolyzed under mild acidic conditions to give the corresponding 17-pseudoaglycones . The tri-O-methylrhamnose at the 9-position of the 17-pseudoaglycone of spinosyn A was hydrolyzed under more vigorous acidic conditions to give the aglycone of spinosyn A . However, these conditions led to decomposition of the 17-pseudoaglycone of spinosyn D, presumably due to more facile protonation of the 5,6-double bond to produce a tertiary carbonium ion which undergoes further rearrangements . Spinosyns J and L (3'-O-demethyl spinosyn A and D, respectively) obtained from fermentation of biosynthetically-blocked mutant strains of Saccharopolyspora spinosa, were oxidized to give the corresponding 3'-keto-derivatives and the resultant keto-sugars were then beta-eliminated under basic conditions to give the 9-pseudoaglycones of spinosyns A and D respectively . Forosamine at the 17-position of the 9-pseudoaglycone of spinosyn D was then readily hydrolyzed to yield the aglycone of spinosyn D.

Res Microbiol, 1997 Sep-Oct, 148(7), 613 - 23
Genetic and biochemical characterization of Saccharomyces cerevisiae mutants resistant to trifluoroleucine; Casalone E et al.; Eighteen mutants resistant to 5',5',5'-trifluoroleucine (TFL), a leucine analog, were isolated in Saccharomyces cerevisiae strains YNN281 and YNN282 . The mutants were characterized genetically and clustered in two groups, one comprising all the dominant (TFL1) and the other one all the recessive (tfl2) mutations . Genetic and biochemical data suggested that the dominant mutations are located on the LEU4 gene, coding for alpha-isopropylmalate synthase I . These mutations resulted in accumulation of leucine as a consequence of the synthesis of an enzyme insensitive to the feedback inhibition by leucine . Leucine excretion in the TFL1 mutants appeared to be affected by the genetic background of the strain and was greatly influenced by lysine metabolism . The measurement of intra- and extracellular amino acid concentrations in prototrophic strains carrying TFL1 or tfl2 genes showed that both were leucine overproducers . Some of the TFL-resistant mutants were tested in alcoholic fermentation of grape must: analysis of the fermentation secondary metabolites showed that the major effect of the TFL-resistant strains was an increased production of isoamyl alcohol compared to that of the parental strain.

Res Microbiol, 1997 Mar-Apr, 148(3), 263 - 9
Glycoside hydrolase production by an anaerobic rumen fungus Caecomyces communis; Bata J et al.; The ruminal fungus Caecomyces communis was grown anaerobically either in a discontinuous cultivation system or in a fermentor with daily withdrawal and addition of fresh medium . Lowe and Orpin media were tested . The best culture conditions for glycoside hydrolase production were obtained in Lowe medium with daily fresh medium addition, whereas the Orpin medium with ruminal fluid was favourable to fungal growth and to the enzyme export process . Among glycoside hydrolases assessed in both culture fluid and cellular homogenate, beta-D-fucosidase activity was preponderant . Most studied enzymes were mainly associated with cells (from 50% to 99%) . Glycoside hydrolase activities were constitutive, but their level was regulated by a carbon source . beta-D-fucosidase and beta-D-xylosidase activity production was activated by the association of glucose plus cellobiose, whereas beta-D-glucosidase activity production was stimulated by cellobiose alone . Enzyme release could be favoured by glucose alone or by Ray grass hay added to glucose plus cellobiose.

J Altern Complement Med, 1998 Fall, 4(3), 289 - 303
The scientific rediscovery of an ancient Chinese herbal medicine: Cordyceps sinensis: part I; Zhu JS et al.; This review presents Cordyceps sinensis (Berk.) Sacc., a fungus highly valued in China as a tonic food and herbal medicine . The extant records show the continued use of C . sinensis is now centuries old . The major chemical, pharmacological, and toxicological studies on C . sinensis and the various derived, cultured, fermented mycelial products currently in use are reviewed from the English and Chinese literature . Preclinical in vitro and in vivo studies and clinical blinded or open-label trials in to date over 2000 patients are reviewed . These studies show the main activities of the fungus in oxygen-free radical scavenging, antisenescence, endocrine, hypolipidemic, antiatherosclerotic, and sexual function-restorative activities . The safety of the fungus, its effects on the nervous system, glucose metabolism, the respiratory, hepatic, cardiovascular, and immune systems, immunologic disease, inflammatory conditions, cancer, and diseases of the kidney will be reviewed in the second part of this article to be published in the winter issue of this journal.

J Chromatogr A, 1998 Aug 21, 817(1-2), 205 - 14
Quantifying biosynthetic human growth hormone in Escherichia coli with capillary electrophoresis under hydrophobic conditions; Jorgensen TK et al.; A method has been developed which is able to quantitate the content of precursor biosynthetic human growth hormone (Pre-bhGH) in the cytosol of E . coli cells containing the gene for human growth hormone (hGH) . The method uses hydrophobic C18 coated capillaries with native biosynthetic human growth hormone (bhGH) as an internal standard . This allows for highly robust and precise determinations as well as the evaluation of the presence of deamidated forms in the cytosol samples . Furthermore, by modifying the running buffer with zwitterionic surfactants and an organic modifier, it is possible to detect a related form with a three sulfur atom Cys-Cys bridge (trisulfide Pre-bhGH) . Thus, a strong tool for monitoring the effect of fermentation conditions on the biosynthesis of bhGH is obtained.

Bioseparation, 1998, 7(2), 117 - 26
IgG and hybridoma partitioning in aqueous two-phase systems containing a dye-ligand; Zijlstra GM et al.; The effect of the important ATPS- and buffer parameters on IgG and hybridoma partitioning in ATPSs containing a PEG-dye-ligand was studied . Objective was to establish selection criteria for effective ligands for extractive fermentations with animal cells in ATPSs . In the presence of 1% PEG-dye-ligand the binding of IgG to the PEG-ligand was affected severely by the Na-chloride concentration . The tie-line length and pH affected IgG partitioning to a lesser extent . The desired partitioning of IgG into the top phase, was only obtained when, in addition to the 10 mmol/kg K-phosphate buffer, no Na-chloride was present . In an ATPS culture medium, with +/- 35 mmol/kg Na-bicarbonate and 60 mmol/kg Na-chloride, increasing the PEG-dye-ligand concentration up to 100% did increase the partition coefficient, but was not effective in concentrating the IgG in the top phase of ATPS culture medium at a pH of 7.8 . Furthermore, addition of the PEG-dye-ligand to ATPS culture medium changed the hybridoma cell partitioning from the bottom phase to the interface.

Biotechnol Prog, 1998 Sep, 14(5), 749 - 55
Effect of hydrodynamic and magnetic stabilization on fluidized-Bed adsorption
Seibert KD, Burns MA.
Direct fermentation broth processing using fluidized beds is extremely advantageous due to the low operating pressure drop of the device and the ability of the bed to process suspended-solids-containing solutions . Unfortunately, the solid particles in fluidized beds typically show a great deal of mixing compared to those in packed beds . This mixing may lead to early breakthrough and inefficient use of adsorptive capacity . Stabilization reduces the solids mixing and improves the performance and efficiency of a fluidized bed . A comparison of packed, fluidized, and stabilized beds reveals that, while normal fluidized beds do contain a significant amount of mixing, the breakthrough behavior of the bed is not drastically different than that of a packed bed . Magnetic stabilization of the bed usually leads to an increase in adsorption efficiency but is dependent on field strength and orientation . Permanently magnetized beds were also investigated and produced breakthrough efficiencies similar to those of packed beds.

Chin J Biotechnol, 1998, 14(1), 53 - 7
Study on kinetics of ergosterol fermentation; Luo H et al.; The kinetic relationships among the consumption of sucrose, production of ergosterol, formation of ethanol, and growth of yeast cells were studied . A two-stage kinetic model was established . The relative deviations between experimental data and simulated results were no more than 20%.

Appl Environ Microbiol, 1998 Oct, 64(10), 4076 - 8
Balance of activities of alcohol acetyltransferase and esterase in Saccharomyces cerevisiae is important for production of isoamyl acetate; Fukuda K et al.; Isoamyl acetate is synthesized from isoamyl alcohol and acetyl coenzyme A by alcohol acetyltransferase (AATFase) in Saccharomyces cerevisiae and is hydrolyzed by esterases at the same time . We hypothesized that the balance of both enzyme activities was important for optimum production of isoamyl acetate in sake brewing . To test this hypothesis, we constructed yeast strains with different numbers of copies of the AATFase gene (ATF1) and the isoamyl acetate-hydrolyzing esterase gene (IAH1) and used these strains in small-scale sake brewing . Fermentation profiles as well as components of the resulting sake were largely alike; however, the amount of isoamyl acetate in the sake increased with an increasing ratio of AATFase/Iah1p esterase activity . Therefore, we conclude that the balance of these two enzyme activities is important for isoamyl acetate accumulation in sake mash.

Appl Environ Microbiol, 1998 Oct, 64(10), 3887 - 92
New hybrids between Saccharomyces sensu stricto yeast species found among wine and cider production strains; Masneuf I et al.; Two yeast isolates, a wine-making yeast first identified as a Mel+ strain (ex . S . uvarum) and a cider-making yeast, were characterized for their nuclear and mitochondrial genomes . Electrophoretic karyotyping analyses, restriction fragment length polymorphism maps of PCR-amplified MET2 gene fragments, and the sequence analysis of a part of the two MET2 gene alleles found support the notion that these two strains constitute hybrids between Saccharomyces cerevisiae and Saccharomyces bayanus . The two hybrid strains had completely different restriction patterns of mitochondrial DNA as well as different sequences of the OLI1 gene . The sequence of the OLI1 gene from the wine hybrid strain appeared to be the same as that of the S . cerevisiae gene, whereas the OLI1 gene of the cider hybrid strain is equally divergent from both putative parents, S . bayanus and S . cerevisiae . Some fermentative properties were also examined, and one phenotype was found to reflect the hybrid nature of these two strains . The origin and nature of such hybridization events are discussed.

Appl Environ Microbiol, 1998 Oct, 64(10), 3831 - 7
Improvement of nitrogen assimilation and fermentation kinetics under enological conditions by derepression of alternative nitrogen-assimilatory pathways in an industrial Saccharomyces cerevisiae strain; Salmon JM et al.; Metabolism of nitrogen compounds by yeasts affects the efficiency of wine fermentation . Ammonium ions, normally present in grape musts, reduce catabolic enzyme levels and transport activities for nonpreferred nitrogen sources . This nitrogen catabolite repression severely impairs the utilization of proline and arginine, both common nitrogen sources in grape juice that require the proline utilization pathway for their assimilation . We attempted to improve fermentation performance by genetic alteration of the regulation of nitrogen-assimilatory pathways in Saccharomyces cerevisiae . One mutant carrying a recessive allele of ure2 was isolated from an industrial S . cerevisiae strain . This mutation strongly deregulated the proline utilization pathway . Fermentation kinetics of this mutant were studied under enological conditions on simulated standard grape juices with various nitrogen levels . Mutant strains produced more biomass and exhibited a higher maximum CO2 production rate than the wild type . These differences were primarily due to the derepression of amino acid utilization pathways . When low amounts of dissolved oxygen were added, the mutants could assimilate proline . Biomass yield and fermentation rate were consequently increased, and the duration of the fermentation was substantially shortened . S . cerevisiae strains lacking URE2 function could improve alcoholic fermentation of natural media where proline and other poorly assimilated amino acids are the major potential nitrogen source, as is the case for most fruit juices and grape musts.

Protein Expr Purif, 1998 Oct, 14(1), 45 - 53
Coexpression of G-CSF with an unglycosylated G-CSF receptor mutant results in secretion of a stable complex; Horan TP et al.; Previously, we have shown that the entire extracellular domain of the granulocyte-colony stimulating factor receptor (sG-CSFr) produced in Chinese hamster ovary (CHO) cells forms a stable complex with its ligand G-CSF, at a stoichiometry of 2:2 . A truncated receptor molecule consisting of the cytokine receptor homology domain and N-terminus Ig-like domain (Ig CRH) behaves quite similarly . Both of these forms of the receptor are highly glycosylated . To address the importance of glycosylation toward receptor activity and stability, and possibly obtain nonglycosylated receptor for crystallization, mutations were made to replace four Asn residues which are N-glycosylated in the truncated receptor . Virtually no receptor was recovered from conditioned media of CHO cells transfected with this mutant construct, although a high-level of mRNA coding for receptor was detected; this mRNA was translated as determined by Western blots of cell lysates . These results indicate that the translated product is apparently not secreted from these cells . Cells transfected with mutant receptor cDNA were cotransfected with a cDNA construct expressing G-CSF in which the single O-glycosylation site was eliminated by mutation . Upon fermentation of the cotransfectants, we observed a large amount of receptor-ligand complex in the conditioned media . The purified unglycosylated complex appeared to be of the same binding stoichiometry and approximate binding affinity as that of complex formed by addition of purified ligand and unmutated receptor . These results show that while glycosylation of sG-CSFr is not necessary for ligand binding, it appears to be crucial in folding and export from the cell .

Biotechnol Prog, 1998 Sep-Oct, 14(5), 722 - 8
Solubilization of recombinant ovine growth hormone with retention of native-like secondary structure and its refolding from the inclusion bodies of Escherichia coli; Khan RH et al.; Ovine growth hormone was expressed in Escherichia coli in the form of inclusion bodies using the pQE-30 expression vector . In a simple fed-batch fermentation, 800 mg/L of recombinant ovine growth hormone (r-oGH) was produced at a cell concentration of 12 g dry cell weight/L . Inclusion bodies were isolated from cells with >95% purity by extensive washing using detergent, and the r-oGH from the purified inclusion bodies was solubilized in 2 M Tris-HCl buffer at pH 12 containing 2 M urea . The r-oGH solubilized in the above conditions exhibited considerable secondary structure as determined by circular dichroism spectra and was immunologically active . Solubilization of the inclusion body protein with retention of native-like secondary structure gave higher yields during refolding . To suppress protein aggregation, refolding was carried out in gel filtration column . Refolding, buffer exchange, and the purification of monomeric r-oGH from aggregated complex was achieved in a single step using gel filtration chromatography . More than 60% of the initial inclusion body protein was refolded into a native-like conformation by the use of this procedure . The refolded protein was characterized by circular dichroism, fluorescence, SDS-PAGE, Western blotting, and radio receptor binding assay and found to be similar to native, pituitary-derived, ovine growth hormone.

Biotechnol Prog, 1998 Sep-Oct, 14(5), 714 - 21
Scale-up and optimization of the low-temperature inducible cspA promoter system; Vasina JA et al.; The performance of the major Escherichia coli cold-shock promoter in directing the synthesis of recombinant proteins at low temperatures was investigated in batch fermentations using a plasmid-encoded transcriptional gene fusion between the cspA promoter region and the lacZ gene . Rapid synthesis of beta-galactosidase was observed when the fermentation broth was chilled to 15 degreesC using a variety of cooling profiles, including one modeling the heat-transfer characteristics of a 60-L pilot plant unit . A linear cooling rate of 0.5 degreesC/min led to optimum recovery yields . For all single-temperature downshift experiments, however, the promoter became repressed 60-120 min after initiation of cooling . Both temperature cycling between 15 and 25 degreesC and stepwise temperature downshifts between 37, 29, 21, and 13 degreesC led to multiple inductions of the cspA promoter . Nevertheless, high-efficiency reinduction was only observed during the first temperature pulse when the former strategy was used and when the cells were held at intermediate temperatures for less than 60 min or more than 120 min in the case of successive downshifts . Promoter repression was abolished in host cells bearing a null mutation in the gene encoding the ribosomal binding factor RbfA, leading to the constitutive and high-level expression of beta-galactosidase for 7 h postshift when shake flask cultures were transferred from 42 to 23 degreesC . The suitability of rbfA cells for cspA-driven recombinant protein production was confirmed in high-density fed-batch fermentations . Our results are consistent with the existence of a cold-shock-induced repressor molecule that must accumulate at a threshold concentration before interfering with the production of proteins placed under cspA transcriptional control.

Eur J Clin Nutr, 1998 Sep, 52(9), 668 - 74
Fermented milk products are associated to ulcer disease . Results from a cross-sectional population study; Elmstahl S et al.; BACKGROUND: Prevalence of peptic ulcer disease has been associated to diet . Some dietary factors seem to have bactericidal effect which may modify the risk of peptic ulcer disease . The objective was to analyze associations between dietary habits and peptic ulcers . DESIGN: A cross sectional population study . SUBJECTS: One thousand, one hundred and thirty-five subjects out of 11700 randomly invited men and women, aged 46-67 y, participating in a diet and disease study during 1991-1993 . The study population comprised of 764 cases with reported peptic ulcer, 142 with dyspeptic symptoms and 229 randomly selected controls . METHODS: X-ray examinations and endoscopies were reviewed and 332 out of 764 peptic ulcer cases were verified . Mean daily intake of foods and nutrients were assessed with a combined 7d menu book and a quantitative food frequency questionnaire, including dietary supplements . RESULTS: Subjects with verified ulcer had lower intake of fermented milk products and vegetables and higher intake of milk, meat and bread than controls . Intake of total fat, saturated and monounsaturated fatty acids and linolenic acid were higher in the ulcer group . Higher intake of fermented milk products, by quintiles showed a decreased ulcer risk; odds ratio 0.82 (0.71-40.95), adjusted for covariates below . Higher intake of milk, by quintiles, was associated with an increased risk of ulcer; odds ratio 1.17 (1.03-1.32) . Smoking, foreign ethnicity and being unmarried or divorced were covariates associated to ulcer . CONCLUSION: This study indicates the multifactorial etiology of peptic ulcer including dietary factors . High intake of fermented milk products was associated with decreased risk for ulcer, whereas increased risk was noted for high milk intake.

Anal Chem, 1998 Sep 15, 70(18), 3809 - 17
Analysis of recombinant human platelet-derived growth factor by reversed-charge capillary zone electrophoresis; Tran A et al.; Reversed-charge capillary zone electrophoresis (RC-CZE) has been developed as a clipping (proteolysis) assay for homodimeric protein recombinant human platelet-derived growth factor (rhPDGF-BB), a major serum mitogenic factor involved in subcutaneous wound healing . When expressed in yeast, the protein is excreted as a fully folded homodimeric protein consisting of two antiparallel B chains held together by two interchain disulfide bonds . During fermentation, internal proteolysis (clipping between residues Arg32 and Thr33) and C-terminal truncation (Arg32 and Thr109) may occur . Internal proteolysis yields three potential forms of rhPDGF-BB: intact (both B chains are intact), single-clipped (one B chain is clipped), and double-clipped (both B chains are clipped) . Clipping also creates new C-terminal sites for further C-terminal truncations and leads to a very complex mixture of isoforms . Routine baseline resolution of these three forms by various modes of HPLC proved unsuccessful . When the disulfide bonds of antiparallel chains are reduced, the complex peptide mixture can be analyzed by RP-HPLC; however, only the level of total clipping is identified . Since RC-CZE separation relies upon differences in molecular charge/size ratio, it can resolve the three rhPDGF-BB forms differing in the additional exposed residues . The choice of reversed-charge CZE columns (amine-coated column) allows proteins of high pI such as rhPDGF-BB (pI > 10) to be readily analyzed while minimizing protein loss from column adsorption . To simplify the electropherogram of clipped forms, the sample is treated first with carboxypeptidase B to reduce the charge microheterogeneity of partial Arg32 truncation . Analysis of rhPDGF-BB by RC-CZE yields a baseline separation between the three forms, intact and single- and double-clipped rhPDGF-BB.

J Appl Microbiol, 1998 Aug, 85(2), 247 - 54
Combined use of immobilized Candida stellata cells and Saccharomyces cerevisiae to improve the quality of wines; Ciani M et al.; Grape must fermentation by the combination of immobilized Candida stellata cells and Saccharomyces cerevisiae was carried out in order to enhance the analytical profiles of wine . Batch and continuous pre-treatment of must with immobilized C . stellata cells, followed by an inoculum of S . Cerevisiae, enhanced the analytical profiles of fermentates . The metabolic interactions between the two yeast species showed a positive influence on reducing sugars, acetaldehyde and acetoin metabolism . Sequential fermentation was the best combination for improving the analytical profiles of wine but caused a loss of viability and metabolic activity of beads by limiting their successive use . Continuous pre-treatment of must on the beads of C . stellata could be a more interesting modality to improve the quality of wines . This biotechnological process could be profitably used to produce specific and special wines.

J Dairy Sci, 1998 Aug, 81(8), 2251 - 6
Inhibition of sulfate reduction to sulfide by 9,10-anthraquinone in in vitro ruminal fermentations; Kung L Jr et al.; We studied the effects of sulfur and 9,10-anthraquinone on in vitro ruminal fermentation and production of hydrogen sulfide . A complete, pelleted diet containing 26.8% acid detergent fiber, 15.9% crude protein, and 0.25 to 0.29% sulfur was used as the basal substrate . Fermentations were conducted using the basal substrate and various sulfur additions (elemental sulfur, thiosulfate, calcium sulfate, and sodium sulfate) with or without varying amounts of 9,10-anthraquinone . An increase in the sulfur content of the substrate to > 1.0% with various sources of sulfur had minimal effects on concentrations of volatile fatty acids, but the production of hydrogen sulfide increased . High amounts of 9,10-anthraquinone (10 and 25 ppm of fluid) decreased the molar proportion of acetate and decreased the production of methane and hydrogen sulfide . However, 9,10-anthraquinone increased the molar proportions of propionate and butyrate . Approximately 70% of 9,10-anthraquinone was recovered after 24 h of in vitro ruminal fermentation . These findings suggest that 9,10-anthraquinone has the potential to reduce the production of methane and hydrogen sulfide in ruminal fermentations.

Protein Eng, 1998 Aug, 11(8), 661 - 7
Effect on thermostability and catalytic activity of introducing disulfide bonds into Aspergillus awamori glucoamylase; Li Y et al.; Two additional disulfide bonds and three combined thermostabilizing mutations were introduced into Aspergillus awamori glucoamylase to test their effects on enzyme thermostability and catalytic properties . The single cysteine mutations N20C, A27C, T72C and A471C were made and combined to produce the double cysteine mutations N20C/ A27C and T72C/A471C . The double cysteine mutants were expressed efficiently in Saccharomyces cerevisiae, and disulfide bonds formed spontaneously after fermentation . At 50 degrees C, the single mutants N20C and A27C had decreased specific activity, whereas the specific activity of the double mutants N20C/A27C and T72C/A471C were similar to wild-type glucoamylase . The N20C/A27C mutation increased thermostability, with an increased activation free energy of 1.5 kJ/mol at 65 degrees C, while the single mutation A27C only slightly increased thermostability and N20C decreased it . The other disulfide bond-forming mutation T72C/A471C did not affect thermostability at pH 4.5 . The N20C/A27C mutation was separately combined with two other thermostabilizing mutations, G137A and S436P . Thermostabilities of all of the combined mutated glucoamylases were additive . N20C/A27C/G137A glucoamylase had higher specific activity than wild-type glucoamylase from 45 to 67.5 degrees C . The disulfide bond between positions 20 and 27 connects the C-terminus of helix 1 and the following beta-turn, suggesting that this region is important for glucoamylase thermostability.

Arzneimittelforschung, 1998 Aug, 48(8), 870 - 80
Appropriate mammalian expression systems for biopharmaceuticals; Werner RG et al.; Process development for biopharmaceuticals is dictated by product quality, drug safety and economy of the manufacturing process . Not surprisingly, these factors also play a key role in the evaluation of mammalian cell expression systems to be used in the production of pharmacologically active glycoproteins . To date, the most prominent candidates for efficient expression of glycoproteins are mammalian cell lines such as mouse fibroblast cells (C 127-BPV), Chinese hamster ovary cells (CHO-DHFR, CHO-NEOSPLA, CHO-GS), mouse myeloma cells (NSO-GS) as well as transgenic animals carrying c-DNA or genomic DNA which codes for the protein of interest . The expression titer in the case of glycoproteins is mainly determined by the promoter construct, the site of integration into the chromosome, the copy number and the type of protein in question . Based on expression titer, CHO-NEOSPLA and NSO-GS expression systems are most effective in the production of monoclonal antibodies and, to a lesser extent, of recombinant DNA derived proteins . However, based on overall product yield, expression of recombinant DNA derived proteins in transgenic animals is by far the most promising system . Therefore, for proteins required in large quantities, transgenic expression systems offer an attractive choice . However, cost of goods for products for which the dosage or the overall annual quantities are low, is dominated by downstream processing, filling, lyophilization and packaging and not by the fermentation process . Such proteins are preferentially produced by classical mammalian cell culture systems . Concerns which have to be addressed with respect to drug safety in the transgenic animal approach are the size of the herd, genetic stability from animal to animal, variation in productivity and in impurity profiles during lactation periods, microbial, viral, mycoplasma and prion contaminants, the dependence on health status and the life span of the animal . In a number of cases glycosylation of the protein is relevant for the prevention of immunogenicity of the protein, the pharmacological activity, the pharmacokinetic profile, solubility and stability against proteolysis . The glycosylation pattern, depending on protein structure, is influenced by the enzymatic system of the host cell as well as by fermentation conditions . Therefore, selection of host cells and culture conditions must take into account the requirement for a specific and stable glycosylation pattern . For the assessment of glycovariants, a number of protein analytical methods such as peptide mapping, isoelectric focusing, oligosaccharide mapping, MALDI-TOF (matrix assisted laser desorption mass spectrometry-time of flight), capillary electrophoresis and specific potency assays are available . In our experiments, glycosylation of proteins expressed in CHO cells was demonstrated to be very stable . Only extreme process times, cultivation methods and ammonium ion concentrations had an influence on the glycosylation profile . Among the three products investigated--tissue plasminogen activator (t-PA), interferon omega and soluble intercellular adhesion molecule (s-ICAM)--t-PA expressed the most stable glycosylation pattern . Only at extreme ammonium concentrations an increase of mannose-5 structures was observed, whereas biantennary complex structures were reduced . On the other hand, interferon omega and s-ICAM showed greater susceptibility to increased ammonium concentrations and to adherent cultivation . Such conditions induced quantitative changes to the glycosylation pattern favoring the appearance of higher branched structures . Short cultivation times resulted in more heterogenous oligosaccharide structures . Since the glycosylation of the three proteins is different in the same host cell, the amino acid sequence of the protein apparently influences the glycosylation pattern and its sensitivity to culture conditions . In NSO-mouse myeloma cells, production of s-ICAM is two times as high as in CHO cells

Oncogene, 1998 Aug 27, 17(8), 999 - 1007
Nuclear targeting of Bax during apoptosis in human colorectal cancer cells; Mandal M et al.; Homeostasis in colonic epithelial cells is regulated by the balance between proliferative activity and cell loss by apoptosis . Because epithelial cells at the apex of colonic crypts undergo apoptosis and proliferative activity is usually restricted to the base of the crypts, it has been proposed that the limited availability of growth factor-signals at the upper portions of the crypts may trigger apoptosis . In the present studies, we investigate the mechanism of apoptosis mediated by growth factor deprivation in colorectal carcinoma cells by delineating the possible involvement of Bax and its subcellular localization . We report that inhibition of epidermal growth factor receptor (EGFR) tyrosine kinase activity and downregulation of EGFR by anti-EGFR mAb 225 induces apoptosis in human colorectal carcinoma DiFi and FET cells . Induction of apoptosis was preceded by enhanced expression of newly synthesized Bax protein, and required protein synthesis . In the mAb 225-treated cells, Bax was redistributed from the cytosol to the nucleus and subsequently, to the nuclear membranes . The observed induction of Bax expression by mAb 225 was not associated with p53 induction . However, mAb 225 treatment also triggered relocalization of p53 from the cytosol to a nuclear membrane-bound form . Induction of Bax and its redistribution to the nucleus of DiFi cells during apoptosis was also demonstrated in response to butyrate, a physiological relevant molecule in colonic epithelial cells as it is the principal short-chain fatty acid produced by bacterial fermentation of dietary fiber in colonic epithelium . Using immunofluorescence and confocal microscopy, we observed that Bax is predominantly localized in the cytosol, but during apoptosis it is localized both inside and along the nuclear membrane . Taken together, these findings suggest that apoptosis induced by growth factor-deprivation or butyrate may involve the subcellular redistribution of Bax in human colorectal carcinoma cells.

Zhonghua Min Guo Wei Sheng Wu Ji Mian Yi Xue Za Zhi, 1994 Nov, 27(4), 153 - 72
Development of new functional immobilized microbial cell systems and their applications; Tanaka H; Immobilized cell technology has been playing a vital role in the development of fermentation processes . For the past several years, I have been working on immobilized cell systems with an aim of developing novel immobilized biosystems where physical, chemical as well as biological functions are incorporated into the immobilization carrier . By efficiently integrating these new functions with the innate abilities of immobilized cells, the area where immobilized cell systems can be utilized will expand, and the process efficiency will be greatly improved.

Trends Microbiol, 1998 Aug, 6(8), 314 - 9
Starting up yeast glycolysis; Goncalves P et al.; Successfully igniting the yeast glycolytic flux during the transition from gluconeogenic to fermentative growth seems to be a matter of balance and coordination between a multitude of events . The contours of the sugar sensing and signalling pathways that regulate this transition are only beginning to emerge.

Infect Immun, 1998 Oct, 66(10), 4804 - 10
Structure and specific activity of macrophage-stimulating lipopeptides from Mycoplasma hyorhinis; Muhlradt PF et al.; Mycoplasmas are potent macrophage stimulators . We describe the isolation of macrophage-stimulatory lipopeptides S-{2, 3-bisacyl(C16:0/C18:0)oxypropyl}cysteinyl-GQTDNNSSQSQQPGS GTTNT and S-{2,3-bisacyl(C16:0/C18:0)oxypropyl}cysteinyl-GQTN derived from the Mycoplasma hyorhinis variable lipoproteins VlpA and VlpC, respectively . These lipopeptides were characterized by amino acid sequence and composition analysis and by mass spectrometry . The lipopeptides S-{2,3-bis(palmitoyloxy)propyl}cysteinyl-GQTNT and S-{2, 3-bis(palmitoyloxy)propyl}cysteinyl-SKKKK and the N-palmitoylated derivative of the latter were synthesized, and their macrophage-stimulatory activities were compared in a nitric oxide release assay with peritoneal macrophages from C3H/HeJ mice . The lipopeptides with the free amino terminus showed half-maximal activity at 3 pM regardless of their amino acid sequence; i.e., they were as active as the previously isolated M . fermentans-derived lipopeptide MALP-2 . The macrophage-stimulatory activity of the additionally N-palmitoylated lipopeptide or of the murein lipoprotein from Escherichia coli, however, was lower by orders of magnitude . It is concluded that the lack of N-acyl groups in mycoplasmal lipoproteins explains their exceptionally high in vitro macrophage-stimulatory capacity . Certain features that lipopolysaccharide endotoxin and mycoplasmal lipopeptides have in common are discussed . Lipoproteins and lipopeptides are likely to be the main causative agents of inflammatory reactions to mycoplasmas . This may be relevant in the context of mycoplasmas as arthritogenic pathogens and their association with AIDS.

Eur J Biochem, 1998 Aug 15, 256(1), 148 - 54
Genes coding for the benzoyl-CoA pathway of anaerobic aromatic metabolism in the bacterium Thauera aromatica; Breese K et al.; Many aromatic compounds are anaerobically oxidized to CO2 via benzoyl-CoA as the common aromatic intermediate . In Thauera aromatica, the central benzoyl-CoA pathway comprises the ATP-driven two-electron reduction of the benzene ring; this reaction uses a ferredoxin as electron donor and is catalyzed by benzoyl-CoA reductase . The first intermediate, cyclohex-1,5-diene-1-carboxyl-CoA, is subsequently hydrated by dienoyl-CoA hydratase to 6-hydroxycyclohex-1-ene-1-carboxyl-CoA . Formation of the main product produced by cell extracts, 3-hydroxypimelyl-CoA, requires at least two further steps; the oxidation of a hydroxyl group and the hydrolytic carbon ring cleavage of a CoA-activated beta-oxoacid . In addition, enoyl-CoA hydratase may come into play . A cluster of eight adjacent genes, which are transcribed in the same direction and may form an operon, was found in this bacterium . The cluster codes for proven and postulated enzymes of the benzoyl-CoA pathway . The genes for the enzymes code for ferredoxin, four subunits of benzoyl-CoA reductase, dienoyl-CoA hydratase, 6-hydroxycyclohex-1-ene-1-carboxyl-CoA dehydrogenase (NAD+), and the ring hydrolyzing enzyme . The deduced amino acid sequences of these proteins were 35-86% similar to the corresponding sequences found in Rhodopseudomonas palustris . Benzoyl-CoA reductase subunits exhibit distinct similarities with 2-hydroxyglutaryl-CoA dehydratase and its ATP-hydrolysing activase protein of Acidaminococcus fermentans as well as with open reading frames of unknown function in other bacteria . Conversion of benzoyl-CoA to 3-hydroxypimelyl-CoA can be explained by a minimal model of the benzoyl-CoA pathway assuming the four enzymes whose genes were characterized and an additional enoyl-CoA hydratase . In R . palustris the dienoyl-CoA hydratase gene is lacking suggesting the operation of a modified benzoyl-CoA pathway with cyclohex-1-ene-1-carboxyl-CoA as intermediate.

J Lipid Res, 1998 Sep, 39(9), 1896 - 9
Surface enhanced Raman spectroscopic monitor of P . acnes lipid hydrolysis in vitro; Weldon MK et al.; Surface enhanced Raman spectroscopy (SERS) at a silver microelectrode was used to monitor bacterial hydrolysis of triglycerides in lipid mixtures that model sebaceous gland secretions . Mixtures of wax esters, squalene, triolein, and triisostearin were used as model skin secretions . The transformation was followed in vitro as changes in the SERS caused by hydrolysis of triglyceride to fatty acid . The fatty acid was adsorbed as its carboxylate, which is readily identified by the characteristic band at ca . 1395 cm(-1) . Co-adsorption of propionate was also observed . The technique can also confirm the presence of bacteria by detection of short chain carboxylic acids released as products of fermentation during the growth of these cells.

Syst Appl Microbiol, 1998 Mar, 21(1), 40 - 9
Isolation and characterization of Thermococcus barossii, sp . nov., a hyperthermophilic archaeon isolated from a hydrothermal vent flange formation; Duffaud GD et al.; A new hyperthermophilic microorganism, Thermococcus barossii, was isolated from rock fragments of a hydrothermal vent flange formation, located along the East Pacific Rise of the Juan de Fuca Ridge . This organism is obligately anaerobic and grows over a temperature range of at least 60-92 degrees C in artificial seawater-based media, containing elemental sulfur, tryptone and yeast extract . The addition of a maltooligosaccharide mixture and tungsten to this medium improved growth to some extent . At the Topt for growth (82.5 degrees C), cell densities as high as 4 x 10(8) cells/ml could be obtained in 18-liter batch fermentations, with a doubling time of approximately 40 minutes, if culture access to elemental sulfur was sufficient . In continuous culture at the same temperature, comparable cell densities could be obtained but only at slower growth rates . Morphologically, T . barossii is coccoid-shaped, forming irregularly-shaped spheres; under optimal conditions, these coccoids become more regular and smaller, a characteristic of other hyperthermophilic archaea . Negatively-stained preparations showed no pili or flagella associated with the cell surface . 16S rRNA sequencing reveals that T . barossii is most similar to Thermococcus celer (99.7%) . Yet, further comparisons with T . celer showed that T . barossii is a new Thermococcus species: different growth temperature optimum (82.5 degrees C vs . 88 degrees C), obligate requirement for sulfur, higher G + C content (60% vs . 56.7%) and 47.7% DNA-DNA hybridization . The nucleotide and translated amino acid sequence for the gene encoding a DNA polymerase from T . barossii was compared to sequences of related genes from other Thermacoccales . The polymerase phylogenies were congruent with those obtained from the 16S rRNA phylogenetic analyses . Based on the high degree of similarity among members of the genus Termococcus for the criteria used thus far, aspects of enzymology may be an important mechanism of differenting one species from another.

J Pediatr, 1998 Sep, 133(3), 401 - 5
Effects of lactose intake on lactose digestion and colonic fermentation in preterm infants; Kien CL et al.; The purpose of this study was to determine whether doubling the lactose concentration in formula for preterm infants lowers the fraction of lactose digested and/or increases the fraction of lactose fermented . Six preterm infants, 31 to 36 weeks' postconceptional age, were fed a standard preterm formula (carbohydrate is 50% lactose and 50% glucose polymer)(SC) and/or the same volume of formula modified to contain lactose as the sole carbohydrate (LAC) . Relative lactose digestion during the LAC formula feeding compared with SC formula feeding was measured by using a stable isotope approach for quantifying the fractional contribution of formula lactose to plasma glucose enrichment . Relative lactose digestion was 0.98 +/- 0.17 (range, 0.70 to 1.19) . Fractional fermentation of lactose was estimated from breath H2 excretion (0.52 +/- 0.34 during LAC feeding and 0.23 +/- 0.22 during SC feeding, P = .11) . The rate of breath H2 excretion was much higher with LAC (1.34 +/- 0.98 mL/h) than with SC (0.27 +/- 0.29, P = .029) . In conclusion, doubling the lactose concentration had only modest effects on fractional lactose digestion . Increased breath H2 excretion with LAC may relate to fermentation of nonlactose sugar or to ill-defined changes in colonic physiology or motility, which could enhance colonic fermentation of malabsorbed sugar by H2-producing bacteria.

Nature, 1998 Sep 3, 395(6697), 65 - 7
Microbiological evidence for Fe(III) reduction on early Earth; Vargas M et al.; It is generally considered that sulphur reduction was one of the earliest forms of microbial respiration, because the known microorganisms that are most closely related to the last common ancestor of modern life are primarily anaerobic, sulphur-reducing hyperthermophiles . However, geochemical evidence indicates that Fe(III) is more likely than sulphur to have been the first external electron acceptor of global significance in microbial metabolism . Here we show that Archaea and Bacteria that are most closely related to the last common ancestor can reduce Fe(III) to Fe(II) and conserve energy to support growth from this respiration . Surprisingly, even Thermotoga maritima, previously considered to have only a fermentative metabolism, could grow as a respiratory organism when Fe(III) was provided as an electron acceptor . These results provide microbiological evidence that Fe(III) reduction could have been an important process on early Earth and suggest that microorganisms might contribute to Fe(III) reduction in modern hot biospheres . Furthermore, our discovery that hyperthermophiles that had previously been thought to require sulphur for cultivation can instead be grown without the production of toxic and corrosive sulphide, should aid biochemical investigations of these poorly understood organisms.

J Biol Chem, 1998 Sep 25, 273(39), 25000 - 5
Proteins of newly isolated mutants and the amino-terminal proline are essential for ubiquitin-proteasome-catalyzed catabolite degradation of fructose-1,6-bisphosphatase of Saccharomyces cerevisiae; Hammerle M et al.; Addition of glucose to cells of the yeast Saccharomyces cerevisiae growing on a non-fermentable carbon source leads to selective and rapid degradation of fructose-1,6-bisphosphatase . This so called catabolite inactivation of the enzyme is brought about by the ubiquitin-proteasome system . To identify additional components of the catabolite inactivation machinery, we isolated three mutant strains, gid1, gid2, and gid3, defective in glucose-induced degradation of fructose-1,6-bisphospha-tase . All mutant strains show in addition a defect in catabolite inactivation of three other gluconeogenic enzymes: cytosolic malate dehydrogenase, isocitrate lyase, and phosphoenolpyruvate carboxykinase . These findings indicate a common mechanism for the inactivation of all four enzymes . The mutants were also impaired in degradation of short-lived N-end rule substrates, which are degraded via the ubiquitin-proteasome system . Site-directed mutagenesis of the amino-terminal proline residue yielded fructose-1,6-bisphosphatase forms that were no longer degraded via the ubiquitin-proteasome pathway . All amino termini other than proline made fructose-1,6-bisphosphatase inaccessible to degradation . However, the exchange of the amino-terminal proline had no effect on the phosphorylation of the mutated enzyme . Our findings suggest an essential function of the amino-terminal proline residue for the degradation process of fructose-1,6-bisphosphatase . Phosphorylation of the enzyme was not necessary for degradation to occur.

Rapid Commun Mass Spectrom, 1998, 12(16), 1085 - 91
Separation of cyclosporins by high-performance liquid chromatography and mass spectrometric study of cyclosporin metabolites; Tuominen J et al.; A semi-preparative (high-performance liquid chromatography) method for separation of cyclosporin metabolites in a fungal fermentation sample was developed . By using the optimized chromatographic separation, 20 cyclosporin metabolites in a process sample were isolated, and their molecular masses measured by double focusing sector mass spectrometry . The structures of some of the cyclosporin congeners were investigated by tandem sector mass spectrometry using fast atom bombardment ionization . The isobaric cyclosporins D ({Val2} CS) and G ({Nva2} CS) were differentiated by significantly different relative intensities of a fragment ion at m/z 30 {CH4N}+ from a precursor ion at m/z 72 {C4H10N}+ . Otherwise the tandem mass spectrometry (MS/MS) spectra of the fragment ions of the two isomers are very similar . Cyclosporin A and iso-cyclosporin A were also analysed by high energy MS/MS . No significant fragment ions were found to provide distinctions between them . Relatively good overviews of process samples containing very similar structures were achieved by combining LC separation, molecular ion recognition and MS/MS characterization.

Biochemistry, 1998 Sep 15, 37(37), 12838 - 46
The delta-subunit of pyruvate ferredoxin oxidoreductase from Pyrococcus furiosus is a redox-active, iron-sulfur protein: evidence for an ancestral relationship with 8Fe-type ferredoxins; Menon AL et al.; Pyruvate ferredoxin oxidoreductase (POR) from the hyperthermophilic archaeon Pyrococcus furiosus (Pf) catalyzes the final oxidative step in carbohydrate fermentation in which pyruvate is oxidized to acetyl-CoA and CO2, coupled to the reduction of ferredoxin (Fd) . POR is composed of two 'catalytic units' of molecular mass approximately 120 kDa . Each unit consists of four subunits, alpha beta gamma delta, with masses of approximately 44, 36, 20, and 12 kDa, respectively, and contains at least two {4Fe-4S} clusters . The precise mechanism of catalysis and the role of the individual subunits are not known . The gene encoding the delta-subunit of Pf POR has been expressed in E . coli, and the protein was purified after reconstitution with iron and sulfide . The reconstituted delta-subunit (recPOR-delta) is monomeric with a mass of 11 879 +/- 1.2 Da as determined by mass spectrometry, in agreement with that predicted from the gene sequence . Purified recPOR-delta contains 8 Fe mol/mol and remained intact when incubated at 85 degreesC for 2 h, as judged by its visible absorption properties . The reduced form of the protein exhibited an EPR spectrum characteristic of two, spin-spin interacting {4Fe-4S}1+ clusters . When compared with the EPR properties of the reduced holoenzyme, the latter was shown to contain a third {4Fe-4S}1+ cluster in addition to the two within the delta-subunit . The reduction potential of the two 4Fe clusters in isolated recPOR-delta (-403 +/- 8 mV at pH 8.0 and 24 degreesC) decreased linearly with temperature (-1.55 mV/ degreesC) up to 82 degreesC . RecPOR-delta replaced Pf Fd as an in vitro electron carrier for two oxidoreductases from Pf, POR and Fd:NADP oxidoreductase, and the POR holoenzyme displayed a higher apparent affinity for its own subunit (apparent Km = 1.0 microM at 80 degreesC) than for Fd (apparent Km = 4.4 microM) . The molecular and spectroscopic properties and amino acid sequence of the isolated delta-subunit suggest that it evolved from an 8Fe-type Fd by the addition of approximately 40 residues at the N-terminus, and that this extension enabled it to interact with additional subunits within POR.

Food Chem Toxicol, 1998 Sep-Oct, 36(9-10), 781 - 9
Safety evaluation of amino peptidase enzyme preparation derived from Aspergillus niger; Coenen TM et al.; An amino peptidase enzyme preparation obtained from Aspergillus niger was subjected to a series of toxicological tests to document the safety for use as a processing aid for food . The enzyme preparation was examined for subacute and subchronic oral toxicity, and mutagenic potential . No evidence of oral toxicity or mutagenicity was found . Administration of the amino peptidase enzyme preparation at doses of 500, 1000 and 2000 mg/kg body weight/day for 90 days did not induce noticeable signs of toxicity . The no-observed-adverse-effect level (NOAEL) of the enzyme preparation in the subchronic toxicity study was 2000mg/kg body weight/day (equivalent to 1152 PHEA units/kg body weight/day) . It can be concluded that no safety concerns were identified in the studies conducted with this amino peptidase enzyme preparation derived from Aspergillus niger and produced under controlled fermentation conditions.

Am J Clin Nutr, 1998 Sep, 68(3), 705 - 10
Small-intestinal digestion of partially resistant cornstarch in healthy subjects; Champ MM et al.; The aims of this study were to measure the amount of starch from partially resistant starches (retrograded and complexed high-amylose cornstarches) escaping small-intestinal digestion in healthy humans by use of an intubation method and to compare these data with data obtained by indirect in vitro methods . Experiments were carried out in vivo in 6 healthy humans by using ileal intubation and stool analysis and in vitro by using 3 different methods for analyzing resistant starch . In intubated subjects, 51 +/- 2% of the retrograded and 21 +/- 2% of the complexed starch was delivered to the ileum and was fermented almost completely in the colon . In vitro estimates of the absorption of resistant starch were much lower . We conclude that technologically modified starches may substantially increase the amount of carbohydrate available for colonic fermentation in humans, but that in vitro measurements of resistant starch are inaccurate for predicting malabsorption in healthy humans.

Int J Syst Bacteriol, 1998 Jul, 48 Pt 3, 983 - 93
Tissierella creatinophila sp . nov., a gram-positive, anaerobic, non-spore-forming, creatinine-fermenting organism; Harms C et al.; A strictly anaerobic, Gram-positive, non-spore-forming bacterium was isolated from sewage sludge which grew on creatinine as sole source of carbon and energy . This new isolate, designated strain KRE 4T, totally degraded creatinine via creatine, sarcosine and glycine to the products acetate, monomethylamine, ammonia and carbon dioxide . Growth on creatinine or creatine was selenium-dependent and stimulated by formate, indicating the involvement of a creatine reductase, sarcosine reductase and/or glycine reductase . This was substantiated by the fact that creatine, sarcosine and glycine were reduced by cell-free extracts . Growth on creatinine or creatine was also possible in the absence of formate, but with an increase in doubling time . The new bacterium occurred as rod-shaped cells, which exhibited an angular form (2-6 microns long and 0.7-1.1 microns wide) and showed motility by means of peritrichous flagella . The G+C content of the DNA was 30 mol % . Comparative 16S rRNA sequence analysis demonstrated that strain KRE 4T represents a new subline within the genus Tissierella . Due to its very restricted substrate spectrum and the inability of whole cells to utilize sarcosine and glycine as intermediates of creatine breakdown, this organism can be readily separated from currently described species of Tissierella . Therefore, based on the phenotypic and phylogenetic distinctiveness of the new isolate, it si proposed that the bacterium be classified as a new species of the genus Tissierella, Tissierella creatinophila sp . nov . The type strain is KRE 4 (= DSM 6911T).

Int J Syst Bacteriol, 1998 Jul, 48 Pt 3, 935 - 40
Description of Acetobacter oboediens sp . nov . and Acetobacter pomorum sp . nov., two new species isolated from industrial vinegar fermentations; Sokollek SJ et al.; Two strains of Acetobacter sp., LTH 2460T and LTH 2458T, have been isolated from running red wine and cider vinegar fermentations, respectively . Taxonomic characteristics of the isolates were investigated . Comparative analysis of the 165 rRNA sequences revealed > 99% similarity between strain LTH 2460T and the type strains of the related species Acetobacter europaeus and Acetobacter xylinus and between strain LTH 2458T and Acetobacter pasteurianus . On the other hand, low levels of DNA relatedness (< 34%) were determined in DNA-DNA similarity studies . This relatedness below the species level was consistent with specific physiological characteristics permitting clear identification of these strains within established species of acetic acid bacteria . Based on these results, the names Acetobacter oboediens sp . nov . and Acetobacter pomorum sp . nov . are proposed for strains LTH 2460T and LTH 2458T, respectively . The phylogenetic positions of the new species are reflected by a 16S rRNA-based tree . Furthermore, a 16S rRNA-targeted oligonucleotide probe specific for A . oboediens was constructed.

J Nutr, 1998 Sep, 128(9), 1481 - 6
D-Tagatose, a stereoisomer of D-fructose, increases hydrogen production in humans without affecting 24-hour energy expenditure or respiratory exchange ratio; Buemann B et al.; In growth studies on rats, the ketohexose D-tagatose has been shown to contribute no net metabolizable energy, and a pronounced thermic effect of the sugar has been suggested to account for the absence of energy . In a double-blind and balanced cross-over design, we measured 24-h energy expenditure in eight normal weight humans in a respiration chamber during the consumption of 30 g D-tagatose or 30 g sucrose/d . Metabolic measurements were performed before and after a 2-wk adaptation period with a 30-g daily intake of the test sugar . Total 24-h energy expenditure and hour-by-hour profile were unaffected by the test sugar . The nonprotein respiratory exchange ratio (RERnp) was similar during consumption of D-tagatose and sucrose . However, the effect on RERnp due to CO2 produced by fermentation of D-tagatose could not be quantified in this study . A significant increase in 24-h H2 production (35%) during D-tagatose administration suggests a substantial malabsorption of the sugar . We found no effects of the 2-wk adaptation period on the measured gas exchange variables . Significantly lower fasting plasma insulin and triglyceride concentrations were observed during D-tagatose administration compared with the sucrose period . No effects of D-tagatose on body weight and composition were seen, but the perception of fullness 2.5 h after the sugar load was greater with D-tagatose . In conclusion, this study does not suggest a pronounced thermic effect of D-tagatose, and other mechanisms seem to be required to explain its lack of net energy.

Am J Respir Crit Care Med, 1998 Sep, 158(3), 998 - 1001
Detection of Mycoplasma pneumoniae in the airways of adults with chronic asthma; Kraft M et al.; Infection with Mycoplasma pneumoniae has been shown to exacerbate asthma in humans . However, the role of M . pneumoniae in the pathogenesis of chronic asthma has not been defined . Eighteen asthmatics with chronic, stable asthma and 11 nonasthmatic control subjects underwent evaluation of the upper and lower airways and serologic analysis to determine the presence of M . pneumoniae, Chlamydia pneumoniae, and seven respiratory viruses through culture, enzyme-linked immunoassay (EIA) and polymerase chain reaction (PCR) . M . pneumoniae was detected by PCR in 10 of 18 asthmatics and one of 11 control subjects (p = 0.02) . In nine of the 10 patients, the organism was detected in bronchoalveolar lavage or bronchial biopsies . Seven of 18 asthmatics and one of 11 control subjects were also positive for M . fermentans and M . genitalium by PCR . All patients' cultures, EIAs, and serology were negative for M . pneumoniae . All PCR and cultures were negative for C . pneumoniae, and all EIAs for respiratory viruses were negative in all subjects . Nine asthmatics and one control subject exhibited positive serology for C . pneumoniae (p = 0.05) . M . pneumoniae was present in the lower airways of chronic, stable asthmatics with greater frequency than control subjects, and may play a role in the pathogenesis of chronic asthma.

Yeast, 1998 Aug, 14(11), 1001 - 6
Suppression of sdh1 mutations by the SDH1b gene of Saccharomyces cerevisiae; Colby G et al.; Transformation of the respiratory-defective mutant (E264/U2) of Saccharomyces cerevisiae with a yeast genomic library yielded two different plasmids capable of restoring the ability of the mutant to grow on non-fermentable substrates . One of the plasmids (pG52/T3) contained SDH1 coding for the flavoprotein subunit of mitochondrial succinate dehydrogenase . The absence of detectable succinate dehydrogenase activity in mitochondria of E264/U2 and the lack of complementation of the mutant by an sdh11null strain indicated a mutation in SDH1 . The second plasmid (pG52/T8) had an insert with reading frame (YJL045w) of yeast chromosome X coding for a homologue of SDH1 . Subclones containing the SDH1 homologue (SDH1b), restored respiration in E264/U2 indicating that the protein encoded by this gene is functional . The expression of the two genes was compared by assaying the beta-galactosidase activities of yeast transformed with plasmids containing fusions of lacZ to the upstream regions of SDH1 and SDH1b . The 100-500 times lower activity measured in transformants harbouring the SDH1b-lacZ fusion indicates that the isoenzyme encoded by SDH1b is unlikely to play an important role in mitochondrial respiration . This is also supported by the absence of any obvious phenotype in cells with a disrupted copy of SDH1b.

Yeast, 1998 Aug, 14(11), 977 - 84
The structure and function of yeast xylose (aldose) reductases; Lee H; Yeast xylose (aldose) reductases are members of the aldo-keto reductase family of enzymes which are widely distributed in a variety of other organisms . In yeasts, these enzymes catalyse the first step of xylose metabolism where xylose is converted to xylitol . In the past 16 years, xylose reductases from yeasts able to ferment or utilize xylose have been isolated and studied mainly because of their importance in xylose bioconversions . In recent years, genes encoding xylose reductases from several yeasts have been cloned and sequenced . A comparison of the primary sequences of yeast xylose reductases with the much better characterized human aldose reductase and human aldehyde reductase reveals that the yeast enzymes are hybrids between aldo-keto reductases and the short chain dehydrogenases/reductases families of enzymes . Why this is so and its evolutionary significance is presently not known . This short review will critically examine the structure and function information that can be gleaned from the sequence comparison . Several interesting questions arise from the sequence comparison and these can provide fruitful areas for further investigations.

Brain Res, 1998 Aug 24, 803(1-2), 34 - 8
Mycoplasma fermentans glycolipid triggers inflammatory response in rat astrocytes; Ben-Menachem G et al.; Mycoplasma fermentans glycolipid (MfGL-II) is a major lipid in the membranes of this AIDS-associated mycoplasma and constituting up to 20% of the total phospholipids of this organism . It was recently shown that MfGL-II, mainly through its phosphocholine moiety, is responsible for the attachment of M . fermentans to host cells . We now show that MfGL-II is also associated with the secretion of inflammatory mediators by cells of the central nervous system . Stimulation of primary rat astrocytes by MfGL-II caused activation of protein kinase C, secretion of nitric oxide (NO) and prostaglandin E2, and augmented glucose utilization and lactate formation in a dose-dependent manner . In an attempt to define the minimal structural requirements for MfGL-II activity, the two O-acylated fatty acids in the molecule were removed . Deacylation pronouncedly reduced the stimulatory activity of the glycolipid, suggesting that the fatty acyl residues are essential . Incubation of MfGL-II with polyclonal anti-MfGL-II antiserum or with monoclonal anti-phosphocholine antibody diminished NO release, whereas incubation of MfGL-II with normal rabbit serum had no effect . It is, therefore, likely that the terminal phosphocholine moiety plays an important role in MfGL-IIs stimulation of glial cells .

Physiol Res, 1997, 46(3), 209 - 13
Effect of yeast culture and phenolic acids on the physiology of rumen fermentation determined in vitro; Zelenak I et al.; The effect of p-hydroxybenzoic acid (HBA), syringic acid (SYA) and yeast culture (YS) on rumen fermentation in vitro has been investigated . Meadow hay was used as a substrate and rumen fluid as an inocula . The yeast culture Levucel contained 5x10(8) yeast cells Saccharomyces cerevisiae per 1 g of dry matter and was used in the amount of 0.5 g/l of the medium . The following combinations of additives were used: hay without additive, hay + YS, hay with 1, 5 or 10 mmol HBA or SYA, and hay + YS with 1, 5 or 10 mmol HBA or SYA . The test tubes were incubated for 96 hours at 39 degrees C . The results showed that 1 mmol HBA had a significant effect on yeast efficacy . This was manifested in the increased degradability of hay dry matter (P <0.05) and enhanced total gas production (P<0.05) . SYA in the same amount combined with yeast had a similar effect on gas production (P<0.05), but hay dry matter degradability was not affected . The results showed a slight effect of phenolic acids and yeast culture on hay rumen fermentation in vitro.

J Antibiot (Tokyo), 1998 Jul, 51(7), 629 - 34
TMC-52A to D, novel cysteine proteinase inhibitors, produced by Gliocladium sp; Isshiki K et al.; New cysteine proteinase inhibitors, TMC-52A, B, C, and D, were isolated from the fungal fermentation broth . On the basis of a taxonomical study, the producing strain, F-2665, was characterized as Gliocladium sp . Spectroscopic analyses and chemical degradation have shown TMC-52A to D to be epoxysuccinyl peptides . TMC-52A to D strongly inhibited cysteine proteinases, in particular, cathepsin L with IC50 values of 13 nM, 10nM, 10nM, and 6nM, respectively.

J Antibiot (Tokyo), 1998 Jul, 51(7), 618 - 23
Erabulenols, inhibitors of cholesteryl ester transfer protein produced by Penicillium sp . FO-5637 . I.Production, isolation and biological properties; Tomoda H et al.; Penicillium sp . FO-5637, a soil isolate, was found to produce a series of inhibitors of cholesteryl ester transfer protein (CETP) . Novel active compounds, designated erabulenols A and B, were isolated from the fermentation broth of the producing strain by solvent extraction, ODS column chromatography and HPLC . Erabulenols A and B inhibit human CETP activity with IC50 values of 47.7 and 58.2 microM in an in vitro assay system containing 200 microM BSA, respectively.

J Biol Chem, 1998 Sep 11, 273(37), 23984 - 92
Characterization of recombinant adrenodoxin reductase homologue (Arh1p) from yeast . Implication in in vitro cytochrome p45011beta monooxygenase system; Lacour T et al.; The mammalian electron transfer chain of mitochondrial cytochrome P450 forms involved in steroidogenesis includes very specific proteins, namely adrenodoxin reductase and adrenodoxin . Adrenodoxin reductase transfers electrons from NADPH to adrenodoxin, which subsequently donates them to the cytochrome P450 forms . The Saccharomyces cerevisiae ARH1 gene product (Arh1p) presents homology to mammalian adrenodoxin reductase . We demonstrate the capacity of recombinant Arh1p, made in Escherichia coli, to substitute for its mammalian homologue in ferricyanide, cytochrome c reduction, and, more importantly, in vitro 11beta-hydroxylase assays . Electrons could be transferred from NADPH and NADH as measured in the cytochrome c reduction assay . Apparent Km values were determined to be 0.5, 0.6, and 0.1 microM for NADPH, NADH, and bovine adrenodoxin, respectively . These values differ slightly from those of mammalian adrenodoxin reductase, except for NADH, which is a very poor electron donor to the mammalian protein . Subcellular fractionation studies have localized Arh1p to the inner membrane of yeast mitochondria . The biological function of Arh1p remains unknown, and to date, no mitochondrial cytochrome P450 has been identified . ARH1 is, however, essential for yeast viability because an ARH1 gene disruption is lethal not only in aerobic growth conditions but also, surprisingly enough, during fermentation.

Alcohol Clin Exp Res, 1998 Aug, 22(5), 1161 - 4
Inhibition of intracolonic acetaldehyde production and alcoholic fermentation in rats by ciprofloxacin; Visapaa JP et al.; Heavy drinking is associated with many gastrointestinal symptoms and diseases, such as rapid intestinal transit time, diarrhea, colon polyps, and colorectal cancer . Acetaldehyde produced from ethanol by intestinal microbes has recently been suggested to be one of the pathogenetic factors related to alcohol-associated gastrointestinal morbidity . Furthermore, acetaldehyde is absorbed from the colon into portal blood and may thus contribute to the development of alcoholic liver injury . The present study was aimed to investigate the significance of gut aerobic flora in intracolonic acetaldehyde formation . For this study, 58 male Wistar rats (aged 9 to 11 weeks) were used . Half of the rats received ciprofloxacin for four consecutive days . Control rats (n = 29) received standard chow . On the fifth day of treatment, 1.5 g/kg body weight of ethanol was administered intraperitoneally to 19 rats receiving ciprofloxacin and 19 control rats . Ten ciprofloxacin-treated and 10 control rats received equal volumes of physiological saline intraperitoneally . Two hours after the injection of ethanol or saline, the samples of colonic contents and blood were obtained . Acetaldehyde and ethanol levels of the samples were determined by headspace gas chromatography . The intracolonic acetaldehyde level 2 hr after ethanol administration was 483+/-169 microM (maximum: 2.7 mM) . High intracolonic acetaldehyde after ethanol injection was significantly reduced by ciprofloxacin treatment . After ciprofloxacin, intracolonic acetaldehyde levels before and after the injection of ethanol were 25+/-4.8 and 23+/-15 microM, respectively . Ciprofloxacin treatment resulted also in significantly higher blood (p < 0.005) and intracolonic (p < 0.0001) ethanol levels than in the control animals . Furthermore, ciprofloxacin treatment totally abolished the formation of endogenous ethanol in the large intestine . This study demonstrates that alcoholic fermentation and intracoIonic acetaldehyde production can be blocked by diminishing the amount of intracolonic aerobic bacteria with ciprofloxacin . Our findings indicate that the bacteriocolonic pathway for ethanol oxidation is mediated almost exclusively by gut aerobic microbes, and this knowledge may provide new insights into the studies on the pathogenesis of alcohol-related gastrointestinal symptoms and diseases.

Nature, 1998 Aug 20, 394(6695), 805 - 9
Structure of a cephalosporin synthase; Valegard K et al.; Penicillins and cephalosporins are among the most widely used therapeutic agents . These antibiotics are produced from fermentation-derived materials as their chemical synthesis is not commercially viable . Unconventional steps in their biosynthesis are catalysed by Fe(II)-dependent oxidases/oxygenases; isopenicillin N synthase (IPNS) creates in one step the bicyclic nucleus of penicillins, and deacetoxycephalosporin C synthase (DAOCS) catalyses the expansion of the penicillin nucleus into the nucleus of cephalosporins . Both enzymes use dioxygen-derived ferryl intermediates in catalysis but, in contrast to IPNS, the ferryl form of DAOCS is produced by the oxidative splitting of a co-substrate, 2-oxoglutarate (alpha-ketoglutarate) . This route of controlled ferryl formation and reaction is common to many mononuclear ferrous enzymes, which participate in a broader range of reactions than their well-characterized counterparts, the haem enzymes . Here we report the first crystal structure of a 2-oxoacid-dependent oxygenase . High-resolution structures for apo-DAOCS, the enzyme complexed with Fe(II), and with Fe(II) and 2-oxoglutarate, were obtained from merohedrally twinned crystals . Using a model based on these structures, we propose a mechanism for ferryl formation.

Lett Appl Microbiol, 1998 Jul, 27(1), 35 - 8
Effect of Quillaja saponaria saponins and Yucca schidigera plant extract on growth of Escherichia coli; Sen S et al.; Escherichia coli K-12 was exposed to Quillaja saponaria saponins from various commercial firms (Sigma, Roth and Nor-feed) and to an extract of Yucca schidigera plant powder (DK Sarsaponin 30) at different concentrations (0.05-1.0% w/v) . A concentration-dependent response was observed . Quillaja saponaria saponins from Sigma increased growth up to 0.1% (w/v) level, whereas Nor-feed and Roth saponins produced maximum growth at a much higher level (0.5 and 0.75%, w/v, respectively) . These results suggest that quillaja saponins from various sources differ in their biological activity, although all three saponins had the same content of vanillin-sulphuric acid reactive moieties . The lyophilized water extract from the DK Sarsaponin powder showed maximum growth at 0.1% (w/v) level . The levels at which maximum growth was observed did not change on subjecting the quillaja or yucca saponins to heat treatment in an autoclave (121 degrees C for 30 min) . All the saponins and the plant extract increased growth of Escherichia coli up to a certain concentration and thereafter decreased growth . In spite of the decreased growth at higher levels of saponins, it was higher compared to the control (without saponin) up to levels of 1% (w/v) for all saponins except Quillaja saponins from Sigma, for which the growth was lower at levels of 0.25% (w/v) and higher . Saponins have the potential to modulate microbial growth in natural and artificial fermenters.

J Appl Microbiol, 1998 Mar, 84(3), 336 - 41
Stability in by-product formation as a strain selection tool of Saccharomyces cerevisiae wine yeasts; Romano P et al.; A strain of Saccharomyces cerevisiae homozygous for different physiological and metabolic characters was inoculated into two grape musts and the stability of the characters was tested by isolating clones at different fermentation stages . A total of 60 cell-clones were collected and asci dissected from each, yielding a total of 1200 single spore cultures, which were then tested for the segregation of several genetically controlled traits . From the parental strain, 10 asci were dissected and the 40 single spore cultures obtained were used as controls . Micro-fermentations were performed with the 200 single spore cultures obtained from clones isolated at the end of Trebbiano and Aglianico must fermentations . The majority of these spore cultures produced amounts of the secondary compounds at the same level as the parental strain . The progeny of three clones from the Trebbiano fermentation exhibited a significant increase in the production of isoamyl alcohol, whereas the progeny of one clone from the Aglianico fermentation differed in the production of acetoin and amyl alcohols . The variability found in the levels of by-products can also affect the organoleptic properties of the final product . The introduction of the 'metabolic characteristics stability' as a selective index for industrial strains is advised.

Trends Biotechnol, 1998 Aug, 16(8), 323 - 8
Shear sensitivity of animal cells from a culture-medium perspective; van der Pol L et al.; Recently, several groups have published data on the shear sensitivity of suspended animal cells and the protective effect of certain polymers . These findings did not, at the time, seem to have great practical application because shear sensitivity did not cause great problems for large-scale applications in sparged and stirred-tank reactors using the then-current culture media and fermentation procedures . However, two recent developments might require renewed attention in sparged animal-cell cultures--protein-free media and new fermentation techniques.

Chem Phys Lipids, 1998 Jun, 93(1-2), 143 - 8
Physiological control on the expression and secretion of Candida rugosa lipase; Lotti M et al.; The fungus Candida rugosa secretes an extracellular lipase whose production is induced by the addition of fatty acids to the culture broth . This lipase is indeed composed by several protein isoforms partly differing in their catalytic properties . Synthesis and secretion of lipase proteins by C . rugosa cells were studied in culture media containing either glucose or oleic acid as the carbon source . It was shown that, according to their regulation, lipase-encoding genes might be grouped in two classes, one of which is constitutively expressed and the other is induced by fatty acids . The synthesis of inducible enzymes is inhibited at the level of transcription by the addition of glucose and, conversely, oleic acid appears to hinder the synthesis of the constitutive lipase . Growth conditions supporting high level expression both in batch and in continuous culture give rise to the intracellular accumulation of enzyme, possibly due to the existence of a rate-limiting step in the transport of the newly synthesized protein . These results suggest the possibility to develop fermentation processes aimed at the control of the enzyme composition.

Appl Microbiol Biotechnol, 1998 Jul, 50(1), 34 - 41
Process development for high-level secretory production of carboxypeptidase Y by Saccharomyces cerevisiae; Shiba Y et al.; In order to develop a production process for carboxypeptidase Y (CPY, yeast vacuolar protease) secreted by Saccharomyces cerevisiae KS58-2D, medium composition, culture conditions, and expression systems were investigated . We found that the addition of histidine to thiamine-free medium, in which CPY production was almost negligible, raised the intracellular thiamine level, resulting in the increase of CPY production . On the basis of the choice of an expression system that uses an inducible GAL10 promoter, reassessment of histidine concentration in the medium, and optimization of the pH level during cultivation (pH 6.5), active CPY was secreted in a quantity of over 400 mg/l, which was more than tenfold that higher than that previously reported . The process developed could be easily scaled-up to industrial-scale fermentation.

Appl Microbiol Biotechnol, 1998 Jul, 50(1), 30 - 3
Poly-(3-hydroxybutyrate) production from whey by high-density cultivation of recombinant Escherichia coli; Wong HH et al.; Recombinant Escherichia coli strain GCSC 6576, harboring a high-copy-number plasmid containing the Ralstonia eutropha genes for polyhydroxyalkanoate (PHA) synthesis and the E . coli ftsZ gene, was employed to produce poly-(3-hydroxybutyrate) (PHB) from whey, pH-stat fed-batch fermentation, using whey powder as the nutrient feed, produced cellular dry weight and PHB concentrations of 109 g l-1 and 50 g l-1 respectively in 47 h . When concentrated whey solution containing 210 g l-1 lactose was used as the nutrient feed, cellular dry weight and PHB concentrations of 87 g l-1 and 69 g l-1 respectively could be obtained in 49 h by pH-stat fed-batch culture . The PHB content was as high as 80% of the cellular dry weight . These results suggest that cost-effective production of PHB is possible by fed-batch culture of recombinant E . coli using concentrated whey solution as a substrate.

Trop Anim Health Prod, 1998 Jun, 30(3), 191 - 6
Comparison of fermented dried blood meal and cooked dried blood meal as protein supplements for growing pigs; King'ori AM et al.; In Kenya, protein supplements for use in pig feed manufacturing are usually in short supply . The available supplements are expensive . Blood, a by-product of livestock processing, is readily available and it can be processed into blood meal . Normally, blood from small slaughterhouses is wasted and adds to environmental pollution . Some pig farmers collect blood from these small slaughterhouses and cook it before feeding it to pigs . Fermentation in molasses has also been suggested as an alternative processing method . The objective of this experiment was to compare the value of cooked dried blood meal (CDBM) and fermented dried blood meal (FDBM) as protein supplements for growing pigs . The results indicated that both methods of processing could be applied by small-scale farmers . However, fermentation of blood is superior to cooking because FDBM supported a higher performance than CDBM when they supplied equal N levels especially at higher levels of N supply.

J Gastroenterol, 1998 Aug, 33(4), 472 - 6
Circadian rhythm of breath hydrogen in young women; Kagaya M et al.; Breath hydrogen levels, which reflect colonic fermentation of undigested starches, are usually low in the fasted state . Fasting levels of breath hydrogen are important for estimation of oro-cecal transit time and diagnosis of lactase deficiency . In young women, however, fasting levels of breath hydrogen are high . To clarify the reason for this, we studied the circadian pattern of breath hydrogen and the effect of alpha-D-galactosidase on fasting breath hydrogen in one study, and the effect of sleep deprivation on fasting breath hydrogen in another study, in 13 women students aged 21-23 years . In the first study, two breath samples were collected, one in the evening and the other the next morning . On another occasion, alpha-D-galactosidase was given before dinner and breath samples were collected the next morning . In the second study, the circadian rhythm of breath hydrogen was assessed for 3 days and the subjects were deprived of sleep on the second night . Breath samples were collected every 30 min, except during the second night when samples were collected at 1-h intervals . Fasting breath hydrogen was 24 +/- 3.9 ppm (mean +/- SE), which did not differ from the value for the previous night . Alpha-D-galactosidase significantly decreased fasting breath hydrogen levels, to 17 +/- 2.4 ppm (P < 0.05) . There was a clear circadian pattern of breath hydrogen, high in the morning and decreasing to the nadir by 16:00 . After dinner, the level increased again and stayed high during the night . Sleep deprivation did not affect fasting levels of breath hydrogen . High fasting breath hydrogen levels in young women followed a circadian pattern and this may have been due, in part, to an high intake of dietary fiber on the previous day.

Lab Anim, 1998 Jul, 32(3), 276 - 83
The effect of different fibre components on growth rate, nutrient digestibility, rate of digesta passage and hindgut fermentation in domesticated rabbits; Chiou PW et al.; Trials were conducted to study the effect of dietary fibre on performance and nutrient digestibility in growing rabbits . The basal diet was supplemented with 12% cellulose, pectin, lignin, or alfalfa, in four different treatments . Twenty-four 4-week-old California male rabbits were randomly allocated into four groups and placed in individual cages . The lignin supplement severely affected both feed intake and performance, pectin second, with dietary cellulose having the least effect . Dietary lignin significantly decreased the digestibility of crude protein, gross energy and dry matter content (P < 0.05) . Rabbits on the pectin supplemented diet digested dry matter, crude fibre and neutral detergent fibre (NDF) better (P < 0.05) than other treatment groups . On the other hand, rabbits in the lignin group digested crude fibre, acid detergent fibre (ADF) and NDF significantly less well than rabbits in other groups (P < 0.05) . Dietary lignin also significantly decreased the caecal concentration of volatile fatty acids (VFA, P < 0.05) but did not significantly affect the molar ratios of the VFAs among treatment groups . The turnover rate of the marker, chromic oxide, in the gastrointestinal (GI) tract of rabbits was 64.94, 51.81, 44.05 and 29.59 h in the pectin, alfalfa, lignin and cellulose treatment groups, respectively . The rate of turnover in the digestive tract significantly influenced digestibility of fibre components but did not significantly influence caecal fermentation.

Yeast, 1998 Jul, 14(10), 923 - 33
Co-existence of two types of chromosome in the bottom fermenting yeast, Saccharomyces pastorianus; Tamai Y et al.; The bottom fermenting yeasts in our collection were classified as Saccharomyces pastorianus on the basis of their DNA relatedness . The genomic organization of bottom fermenting yeast was analysed by Southern hybridization using eleven genes on chromosome IV, six genes on chromosome II and five genes on chromosome XV of S . cerevisiae as probes . Gene probes constructed from S . cerevisiae chromosomes II and IV hybridized strongly to the 820-kb chromosome and the 1500-kb chromosome of the bottom fermenting yeast, respectively . Five gene probes constructed from segments of chromosome XV hybridized strongly to the 1050-kb and the 1000-kb chromosomes . These chromosomes are thought to be S . cerevisiae-type chromosomes . In addition, these probes also hybridized weakly to the 1100-kb, 1350-kb, 850-kb and 700-kb chromosome . Gene probes constructed from segments including the left arm to TRP1 of chromosome IV and the right arm of chromosome II hybridized to the 1100-kb chromosomes of S . pastorianus . Gene probes constructed using the right arm of chromosome IV and the left arm of chromosome II hybridized to the 1350-kb chromosome of S . pastorianus . These results suggested that the 1100-kb and 1350-kb chromosomes were generated by reciprocal translocation between chromosome II and IV in S . pastorianus . Three gene probes constructed using the right arm of chromosome XV hybridized weakly to the 850-kb chromosome, and two gene probes from the left arm hybridized weakly to the 700-kb chromosome . These results suggested that chromosome XV of S . cerevisiae was rearranged into the 850-kb and 700-kb chromosomes in S . pastorianus . These weak hybridization patterns were identical to those obtained with S . bayanus . Therefore, two types of chromosome co-exist independently in bottom fermenting yeast: one set which originated from S . bayanus and another set from S . cerevisiae . This result supports the hypothesis that S . pastorianus is a hybrid of S . cerevisiae and S . bayanus.

Lett Appl Microbiol, 1998 Jun, 26(6), 452 - 5
Diversity of Saccharomyces strains in wine fermentations: analysis for two consecutive years; Sabate J et al.; An ecological study of Saccharomyces cerevisiae strains in spontaneous alcoholic fermentation has been conducted in the same winery for two consecutive years (1994 and 1995) . Yeast cells were identified and characterized using mitochondrial DNA restriction analysis . Although a great diversity of wild strains was observed, a sequential substitution of S . cerevisiae strains during the different phases of fermentation was detected . Furthermore, the most frequent strains were encountered in both years, and the dynamic populations were not influenced by climatic conditions . Finally, the RsaI restriction enzyme produced a species-specific pattern which allowed the identification of all the isolates as S . cerevisiae.

Lett Appl Microbiol, 1998 Jun, 26(6), 395 - 8
Isolation of Escherichia coli O86:K61 producing cyto-lethal distending toxin from wild birds of the finch family; Foster G et al.; Escherichia coli was recovered from selected tissues of 43 out of a total of 46 finches found dead in the Scottish Highlands during April-May of 1994 and 1995 . The isolates did not ferment sorbitol, rhamnose, sucrose or melibiose; they belonged to serogroup O86:K61, produced cytolethal distending toxin (CLDT) and possessed the eae gene sequence . The consistent recovery of organisms producing CLDT and possessing the eae gene suggests that these organisms may have played a significant role in the finch mortalities.

Int J Food Sci Nutr, 1998 Mar, 49(2), 93 - 9
Cyanogenic potential of cassava flour: field trial in Mozambique of a simple kit; Cardoso AP et al.; The cyanogenic potential (ppm HCN equivalents) of 80 samples of cassava flour (obtained from the Mujocojo and Terrene-A areas of Nampula Province and the markets of Nampula City in Mozambique) were determined using a new simple kit, based on the use of picric acid paper (Egan et al., 1997) . The kit is compact, requires only a small amount of water and is very simple to use in the field . Comparison with the results of a semi-quantitative method shows a mean deviation between the two methods of 20% (SD 12%) . All samples fitted a single population distribution with a mean value of 45 ppm HCN equivalents (SD 37) . Two maxima were observed in the distribution curve at 11-20 and 41-50 ppm . Five samples exceeded 100 ppm with two values of 200 ppm . The WHO safe level for cyanogens in cassava flour is 10 ppm . The lowest levels (2 and 6 ppm) were obtained from cassava flour prepared from sweet cassava . Over 76 samples the mean value of the cyanogenic potential of cassava flour produced by heap fermentation is only one half as large as that produced by sun-drying (P < 0.005) . Interventions needed to reduce cyanogen levels are (1) improvements in processing methods, such as replacement of sun-drying by heap fermentation, (2) introduction of additional vegetables, pulses and fruit to alleviate the monotonous cassava diet of the people and (3) introduction of high-yielding, disease-resistant, low-cyanide cultivars.

J Antibiot (Tokyo), 1997 Jul, 50(7), 551 - 5
UK-3A, a novel antifungal antibiotic from Streptomyces sp . 517-02: fermentation, isolation, structural elucidation and biological properties; Ueki M et al.; A novel antifungal antibiotic, UK-3A, was obtained from the mycelial cake of Streptomyces sp . 517-02 . UK-3A was very similar in structure to UK-2A, a structural relative of antimycin A . The antifungal spectrum of UK-3A was relatively broad (MICs for yeasts and filamentous fungi: 1.56-6.25 and 0.39-1.56 micrograms/ml, respectively) . The cytotoxic activity of UK-3A was weak (IC50: 18-100 micrograms/ml).

J Antibiot (Tokyo), 1997 Jul, 50(7), 537 - 42
Lymphostin (LK6-A), a novel immunosuppressant from Streptomyces sp . KY11783: taxonomy of the producing organism, fermentation, isolation and biological activities; Nagata H et al.; In the course of screening for inhibitors of the lymphocyte kinase, Lck (p56lck), aiming at novel immunosuppressants, we isolated a novel alkaloid, lymphostin (LK6-A), from the culture broth of Streptomyces sp . KY11783 . Lymphostin was produced in a fermentation medium supplemented with a highly porous polymer resin, which prevented the degradation of this compound in the culture broth . Lymphostin inhibited the kinase activity of Lck with an IC50 value of 0.05 microM, and exhibited potent inhibitory activity against the mixed lymphocyte reaction (MLR) with an IC50 value of 0.009 microM.

J Antibiot (Tokyo), 1998 Jun, 51(6), 553 - 9
Fluostatins A and B, new inhibitors of dipeptidyl peptidase III, produced by Streptomyces sp . TA-3391 . I . Taxonomy of producing strain, production, isolation, physico-chemical properties and biological properties; Akiyama T et al.; New inhibitors of dipeptidyl peptidaseIII (EC 3.4.14.4) from human placenta, designated as fluostatins A and B, were discovered in the fermentation broth of a strain isolated in our institute . The strain has been identified as Streptomyces sp . TA-3391 on the basis of taxonomic studies . Fluostatins A and B were purified by Diaion HP-20 chromatography, ethyl acetate extraction, silica gel chromatography and reverse phase preparative HPLC . With the synthetic substrate, arginyl-arginine-2-naphthylamide, the IC50 values of fluostatins A and B were 0.44 and 24.0 micrograms/ml, respectively . Fluostatins A and B were slightly inhibitory against other dipeptidyl peptidases . Fluostatin A showed mixed-type (competitive and noncompeptitive) inhibition with human leucine-enkephalin as a substrate, and the inhibition constant (Ki) was 14.2 microM.

J Antibiot (Tokyo), 1998 Jun, 51(6), 545 - 52
K1115 A, a new anthraquinone that inhibits the binding of activator protein-1 (AP-1) to its recognition sites . II . Taxonomy, fermentation, isolation, physico-chemical properties and structure determination; Naruse N et al.; A new inhibitor of the action of activator protein-1 (AP-1), designated K1115 A, was isolated from the fermentation broth of an actinomycete strain Mer-K1115 . K1115 A was determined to be a new anthraquinone, 3,8-dihydroxy-1-propylanthraquinone-2-carboxylic acid, based on spectroscopic analysis, derivatization experiments and biosynthetic studies with 13C-enriched acetic acid . Two co-produced compounds, K1115 B1 and B2, were also isolated and characterized as new members of the naphthopyranomycin and exfoliamycin group.

J Dairy Sci, 1998 Jul, 81(7), 1991 - 2000
Effect of the synchronization of the degradation of dietary crude protein and organic matter and feeding frequency on ruminal fermentation and flow of digesta in the abomasum of dairy cows; Shabi Z et al.; Four Holstein cows in midlactation were equipped with ruminal and abomasal cannulas and used to study the effect of synchronized degradation of crude protein (CP) and organic matter (OM) and feeding frequency on digestion and outflow of nutrients . A 4 x 4 Latin square design was used . Diets were arranged in a 2 x 2 factorial design; the four diets contained high ruminally degradable OM and high ruminally degradable CP, high ruminally degradable OM and low ruminally degradable CP, low ruminally degradable OM and high ruminally degradable CP, and low ruminally degradable OM and low ruminally degradable CP . In each period, cows were fed four times daily from d 1 to 14 and two times daily from d 15 to 28 . Mean daily ruminal ammonia N concentration was reduced by high ruminally degradable OM, low ruminally degradable CP, and twice daily feeding . Fluctuation in ruminal ammonia N was lower when cows were fed four times daily than when cows were fed twice daily . Plasma urea N concentrations were lower for cows fed diets that were high in ruminally degradable CP . Higher CP flow in the abomasum was found for cows fed the diet containing high ruminally degradable OM and low ruminally degradable CP . Microbial dry matter and CP flow to the abomasum were higher for cows fed twice daily than for cows fed four times daily . Flow of OM in the abomasum was not altered by concentrations of ruminally degradable OM or CP . These results suggest that the available energy in the rumen (ruminally degradable OM) is the most limiting factor for ruminal N utilization under our experimental conditions . Use of these data may improve the prediction of plasma urea N.

J Dairy Sci, 1998 Jul, 81(7), 1972 - 84
Performance, ruminal fermentation, and site of starch digestion in early lactation cows fed corn grain harvested and processed differently; Knowlton KF et al.; Two experiments were conducted to assess the effects of corn grain processing on performance, ruminal fermentation, and starch digestion in early lactation dairy cows . Diets were based on wilted alfalfa silage and high moisture or dry corn grain that was either ground or rolled . Thirty-four cows (17 multi-parous) were used to measure effects on intake and lactational performance in a free-stall environment during wk 2 to 15 postpartum . Grinding increased dry matter intake, particularly for cows fed diets containing dry corn, and tended to increase yields of milk, protein lactose, and SNF . Cow performance was not affected by the moisture content of the corn grain . In the digestion experiment, six cows (43 d of lactation) with ruminal, duodenal, and ileal cannulas were used to measure ruminal and intestinal digestion . Search digestion in the rumen and small intestine was greater for high moisture corn, but disappearance of starch in the large intestine was greater for dry corn . Both the grinding process and the high moisture content of the corn increased starch digestibility in the total tract . Flow of microbial N in the duodenum was not affected by treatment . High moisture corn increased starch digestion in the rumen and total tract and enhanced ruminal fermentation as indicated by increased volatile fatty acids and decreased NH3 concentrations in the rumen . In the production experiment, however, only grinding improved the value of corn; ensiling at high moisture content had little effect.

J Dairy Sci, 1998 Jul, 81(7), 1946 - 55
Effects of form of the diet on anatomical, microbial, and fermentative development of the rumen of neonatal calves; Beharka AA et al.; Eight neonatal, Holstein bull calves were paired by birth date and birth weight and randomly assigned to either a finely ground or unground control diet (chopped hay and rolled grain) to study the effects of the physical form of the diet on anatomical, microbial, and fermentative development of the rumen . The diets varied in particle size but were identical in composition (25% alfalfa hay and 75% grain mix) . Calves were fed milk at 8% of birth weight daily until weaning . Feed intake was equalized for each pair of calves . Ruminal fluid samples were collected from ruminal cannulas to determine pH, fermentation products, and buffering capacity and to enumerate bacteria . Calves were slaughtered at 10 wk of age, and weights of the full and empty reticulorumen, abomasum, and omasum were recorded . Ruminal tissue samples were taken to assess papillary development by morphometric measurements . Calves had similar body weights at wk 10 . Ruminal pH was affected by age and was lower for calves fed the ground diet . Total anaerobic bacterial counts were not affected by the physical form of the diet; however, calves fed the ground diet had lower numbers of cellulolytic bacteria and higher numbers of amylolytic bacteria than did calves fed the unground diet . Physical form of the diet did not affect the weights of the reticulorumen whether full or empty . However, calves fed the ground diet had heavier omasum weights, both full and empty . Physical form of the diet affected papillary size and shape but did not influence the muscle thickness of rumen . Results indicated that the physical form of the diet had a significant influence on the anatomical and microbial development of the forestomac and, therefore, might influence future performance.

J Food Prot, 1998 Jun, 61(6), 657 - 61
Reduction of Escherichia coli O157:H7 populations in soy sauce, a fermented seasoning; Masuda S et al.; We studied five Escherichia coli O157:H7 strains in soy sauce which was incubated at 4, 18, or 30 degrees C after inoculation . The cell numbers of E . coli O157:H7 decreased to an undetectable level (<20 CFU/ml) within 9 days in all the soy sauce samples at 30 degrees C, but did not decrease in the 0.1 M phosphate-buffered saline (pH 7.0) control solution under the same conditions . Soy sauce reduced the cell numbers of bacteria at 18 degrees C to a lesser extent than at 30 degrees C, but to a greater extent than at 4 degrees C . Components of soy sauce such as 10% or 16% NaCl, 5% ethanol, lactic acid, or acetic acid at pH 4.5, sodium benzoate (0.6 g/kg), or p-hydroxybenzoic acid n-butyl ester (0.05 g/liter) caused a reduction of the E . coli O157:H7 population at 30 degrees C, and the anti-E . coli O157:H7 effect of each component was less than that of soy sauce . The fate of E . coli O157:H7 cells in a buffered solution containing various components of soy sauce resembled that in soy sauce at 30 degrees C, which demonstrated the importance of the combination of the soy sauce components for its anti-E coli O157:H7 action.

J Food Prot, 1998 Feb, 61(2), 146 - 51
Survival of Escherichia coli O157:H7 during the manufacture of pepperoni; Riordan DC et al.; This study investigated the growth and survival of Escherichia coli O157:H7 during the manufacture of pepperoni to determine whether a 5-log10-unit decline in numbers, as recommended by the U.S . Food Safety and Inspection Service (FSIS), could be achieved . A range of pepperoni formulations with variations in salt (2.5 to 4.8%) and sodium nitrite (100 to 400 ppm) levels, and with pH (4.4 to 5.6) adjusted by manipulation of dextrose concentrations were prepared . The batters produced were inoculated with E . coli O157:H7 380-94 at a level of approximately 6.70 log10 CFU/g; changes in pathogen numbers, pH, titratable acidity, and sodium nitrite concentrations were monitored during fermentation and drying . With the standard commercial formulation (i.e., 2.5% salt, 100 ppm sodium nitrite, pH 4.8) E . coli O157:H7 numbers declined by approximately 0.41 log10 CFU/g during fermentation and a further 0.43 log10 CFU/g during subsequent drying (7 days) . A regression equation was fitted to the data which showed significantly (P < 0.001) greater reductions in pathogen numbers in samples with increased salt and sodium nitrite contents and lowered pH . However declines were in all cases less than the target reduction of 5 log10 CFU/g.

J Food Prot, 1998 Jan, 61(1), 78 - 86
Degradation of pectic polysaccharides in pickled green olives; Sanchez-Romero C et al.; The changes that occur in the pectic fractions in the cell wall of olives of the Manzanilla variety (Olea europaea pomiformis) during processing (initial treatment at high pH and subsequent lactic fermentation) have been researched . After studying various conditions for fractionating the pectic polysaccharides, the most adequate were chosen, involving sequential extraction with water, imidazole-hydrochloric acid buffer, sodium carbonate, 1 M potassium hydroxide, and 4 M potassium hydroxide . In the unprocessed fruit, the fractions studied consist mainly of high-molecular-weight acidic polysaccharides (70 to 250 kDa): homogalacturonans, rhamnogalacturonans, and branched arabinans . These were found in different proportions depending on the extraction agent used . At the same time, significant amounts of relatively low-molecular-weight (10 to 10.5 kDa) neutral branched arabinans were found in the water-soluble fraction . As a result of the processing, changes occurred in the proportions of the different groups of polysaccharides in accordance with changes in their solubility characteristics . These changes were reflected in the processed fruit by (i) and increase in the neutral branched arabinans in the water-soluble fraction due to the increased presence of such polysaccharides originally found in the carbonate and 4 M KOH-soluble fractions; (ii) an increase in homogalacturonans and rhamnogalacturonans, without significant changes in molecular weights, in the imidazole-soluble fraction as a result of the increased presence of corresponding polysaccharides originally found in the carbonate-soluble and water-soluble fractions; (iii) a substantial increase in uronic acids in the 1 M potassium hydroxide-soluble fraction, preferentially as low-molecular-weight polysaccharides; and (iv) a solubilization of arabinans in the 4 M potassium hydroxide-soluble fraction.

Int J Food Microbiol, 1998 Jun 30, 42(1-2), 91 - 9
Protection by fungal starters against growth and secondary metabolite production of fungal spoilers of cheese; Nielsen MS et al.; The influence of fungal starter cultures on growth and secondary metabolite production of fungal contaminants associated with cheese was studied on laboratory media and Camembert cheese . Isolates of the species Penicillium nalgiovense, P . camemberti, P . roqueforti and Geotrichum candidum were used as fungal starters . The species P . commune, P . caseifulvum, P . verrucosum, P . discolor, P . solitum, P . coprophilum and Aspergillus versicolor were selected as contaminants . The fungal starters showed different competitive ability on laboratory media and Camembert cheese . The presence of the Penicillium species, especially P . nalgiovense, showed an inhibitory effect on the growth of the fungal contaminants on laboratory media . G . candidum caused a significant inhibition of the fungal contaminants on Camembert cheese . The results indicate that G . candidum plays an important role in competition with undesirable microorganisms in mould fermented cheeses . Among the starters, P . nalgiovense caused the largest reduction in secondary metabolite production of the fungal contaminants on the laboratory medium . On Camembert cheese no significant changes in metabolite production of the fungal contaminants was observed in the presence of the starters.

Int J Food Microbiol, 1998 Jun 16, 41(3), 169 - 75
Molecular analysis of yeast population dynamics: effect of sulphur dioxide and inoculum on must fermentation; Constanti M et al.; The effects of sulphur dioxide and a commercial starter inoculum on yeast population dynamics have been analysed by a molecular approach . Yeast identification from fermenting Carinyena grape musts was performed by RFLP's of mtDNA and rRNA-coding DNA . As expected, the use of a commercial inoculum speeded up the start of fermentation, while SO2 addition limited the development of non-Saccharomyces species . However, this effect was also observed with yeast inoculation . Further analysis of population dynamics could lead to a recommendation for the reduction of the dosage of SO2 by the addition of appropriate inoculum of yeasts in the must . Furthermore, the timing of inoculum addition could be modified to allow a proper contribution of non-Saccharomyces species . Molecular biology analysis of population dynamics could provide a tool to efficiently reduce the dosage of SO2 and adjust the timing of inoculum addition.

Biotechnol Annu Rev, 1996, 2, 373 - 89
Biochemical and molecular approaches for production of pravastatin, a potent cholesterol-lowering drug; Serizawa N; The intensive search for inhibitors of cholesterol biosynthesis by screening culture broths has spanned more than 20 years here at Sankyo . Resulting from our efforts, ML-236B was discovered in Japan as the first potent and specific inhibitor of HMG-CoA reductase . This compound contributed-to the Nobel Prize-winning work of Goldstein and Brown in which they elucidated the mechanisms of the LDL receptor pathway . After the discovery of ML-236B, many attempts were performed to find other HMG-CoA reductase inhibitors, and some potent inhibitors including pravastatin have already been launched . HMG-CoA reductase inhibitors are in worldwide clinical use and play a pivotal role in the therapy of hyperlipidemic patients . Pravastatin is produced by a two-step fermentation, firstly ML-236B is produced by Penicillium citrinum followed by the hydroxylation of ML-236B by S . carbophilus to form pravastatin . Recent advances in the molecular characterization of the Cyt P-450sca-2 and their responsiveness to ML-236B and PB in bacterial cultures should help elucidate the underlying cellular and molecular mechanisms of ML-236BNa and PB induction . In an effort to increase the productivity of this fermentation process, new technologies have been developed, and the mechanism of hydroxylation has been extensively investigated.

Biotechnol Annu Rev, 1996, 2, 85 - 121
Production of secondary metabolites by solid-state fermentation; Barrios-Gonzalez J et al.; Microbial secondary metabolites are useful high value products that are normally produced by liquid culture; but could be advantageously produced by solid-state fermentation (SSF) . Particularly if SSF could benefit from a deeper understanding of microbial physiology in a solid environment . Recent research indicates that different kind of secondary metabolites can be produced by SSF: antibiotics, phytohormones, food grade pigments, alkaloids, etc . Physiology in SSF shows several similarities with physiology in liquid medium, so similar strategies must be adapted for efficient processes . However, there are certain particularities of idiophase in solid medium which dictate the need for special strains.

Anticancer Res, 1998 Jul-Aug, 18(4A), 2353 - 8
Effect of Avemar and Avemar + vitamin C on tumor growth and metastasis in experimental animals; Hidvegi M et al.; Because of the observed immunostimulatory actions of a new fermented wheat germ extract--with standardized benzoquinone composition--we have investigated the eventual tumor growth- and metastasis-inhibiting effects of this preparation (Avemar) applied alone or in combination with vitamin C . Tumor models of different origin {a highly metastatic variant of the Lewis lung carcinoma (3LL-HH), B16 melanoma, a rat nephroblastoma (RWT-M) and a human colon carcinoma xenograft (HCR25)}--kept in artificially immunosuppressed mice were applied . The metastasis-inhibiting effects of the treatments have been studied both in the presence and in the absence (following surgical removal) of the transplanted primary tumors . Combined treatments with Avemar and vitamin C--administered synchronously--profoundly inhibited the metastasis formation in all the applied tumor models while, treatments with vitamin C alone did not exert such an inhibiting effect on the metastasizing process . The degree of the observed metastasis inhibition in certain models was significant, while in others--although it was meaningful--did not prove to be significant . It is noteworthy that treatment with Avemar alone in certain models exerted a more pronounced inhibiting effect on metastasis formation than the synchronous combined treatment with Avemar and vitamin C . Furthermore, if the time schedule of the combined treatment was changed (vitamin C--instead of being administered synchronously--was given one hour after the treatments with Avemar), the vitamin C rather decreased the metastasis inhibiting effect of Avemar . It should be mentioned however, that in the case of rat nephroblastoma, a different response was observed: while, in the case of synchronous combination significant inhibition of metastasis formation was observed, treatment with Avemar alone did not produce metastasis-inhibition . It is noteworthy that in this model the metastasis-inhibiting effect of the synchronous combination treatment proved to be even more pronounced if Avemar was administered in a 100 times smaller dose than its regularly applied dosage . Treatment with Avemar and vitamin C--administered in combination or separately--in the majority of experimental models (with the exception of rat nephroblastoma) did not inhibit the growth of the primary tumors . It is reasonable, therefore, to suppose that in the observed metastasis-inhibiting effect the eventual proliferation inhibiting effect of these remedies does not play an important role . According to the results of other experiments--carried out in our laboratory in parallel with those described here--Avemar proved to have a meaningful immunostimulatory effect . It might therefore be suggested that the observed metastasis-inhibiting effect of this preparation may be mainly due to its immunostimulatory properties . The possible therapeutic benefits of Avemar and Avemar plus vitamin C are also discussed.

Am J Clin Nutr, 1998 Aug, 68(2 Suppl), 484S - 487S
Dietary interventions to prevent zinc deficiency; Gibson RS et al.; This review describes household dietary strategies to improve the content and bioavailability of zinc in predominantly plant-based diets and the implementation of these strategies in a community-based dietary intervention study in rural southern Malawi . The strategies involve increasing intakes of foods with high bioavailable-zinc contents, absorption enhancers, or both and using germination, fermentation, and soaking to reduce intake of phytic acid, a potent inhibitor of zinc absorption . The strategies were implemented at the household level in Malawi through a participatory research process that focused on building relationships with the community and involving them in the design, implementation, and monitoring and evaluation processes . In this way, community participation and awareness of zinc deficiency might be enhanced and the dietary strategies planned will be appropriate and sustainable.

J Chromatogr B Biomed Sci Appl, 1998 Jun 26, 711(1-2), 265 - 75
Amine-based aqueous polymers for the simultaneous titration and extraction of lactic acid in aqueous two-phase systems; Planas J et al.; The partitioning of 10% (w/w) lactic acid in ethylene oxide propylene oxide (EOPO) random copolymers and dextran T500 aqueous two-phase systems was studied . An analysis of variance design was applied to investigate the effect of pH, polymer concentration, and addition of polyethyleneimine to the aqueous two-phase systems . The lowest lactate partition coefficient of 0.09 was obtained at pH 6 in the systems containing 7.2% (w/w) polyethyleneimine . The use of polyethyleneimine as titrating base during the fermentative production of lactic acid was evaluated in batch fermentations with 100 g/l glucose . Yield and productivity of polyethyleneimine titrated fermentations compared with those obtained in fermentations titrated with NaOH and KOH.

J Chromatogr B Biomed Sci Appl, 1998 Jun 26, 711(1-2), 97 - 109
Purification of recombinant apolipoprotein A-1Milano expressed in Escherichia coli using aqueous two-phase extraction followed by temperature-induced phase separation; Persson J et al.; A method for purification of recombinant apolipoprotein A1 in aqueous two-phase systems has been studied . A mutant of apolipoprotein A-1, the Milano variant, was expressed in E . coli . Phase systems containing ethylene oxide (EO)-propylene oxide (PO) random copolymers have been used . These polymers are thermoseparating and have the ability to separate into one water-rich and one polymer-rich phase when heated above a critical temperature i.e . the cloud point . The filtrate from an E . coli fermentation was added to a primary aqueous two-phase system composed of an EO-PO copolymer and Reppal, which is an inexpensive hydroxypropyl starch . Apolipoprotein A-1 was partitioned to the top EO-PO copolymer phase and contaminating proteins to the bottom starch phase . The phase diagrams for Reppal PES 100-EO50PO50 (Ucon) and Reppal PES 100-EO30PO70 were determined . The effect on partitioning, when changing parameters such as polymer concentration, type of polymer, protein concentration, pH, salt concentration and volume ratio, were studied . Studies on E . coli DNA partitioning showed that DNA could be partitioned strongly to the bottom phase . An optimal system was scaled up from 5 g to 5 kg with similar degrees of purification, i.e . 2.5 and 2.7 and yields of 79% and 82% respectively . Furthermore temperature-induced phase formation was used for separation of apolipoprotein A-1 from the copolymer by raising the temperature above the copolymer cloud point; thus, recovering protein in a 'clean' water phase.

J Chromatogr B Biomed Sci Appl, 1998 Jun 26, 711(1-2), 61 - 8
Poly(ethylene glycol)-salt aqueous two-phase systems with easily recyclable volatile salts; van Berlo M et al.; Aqueous two-phase systems (ATPSs) have great potential in the downstream processing of fermentation products . However, the consumption of large amounts of auxiliary materials limits application in industrial practice . Promising alternatives to the salts used so far are volatile salts such as ammonium bicarbonate and ammonium carbamate, which can be recycled to the extraction system as gaseous carbon dioxide and ammonia . In this work, it is demonstrated that ammonium carbamate in combination with poly(ethylene glycol) (PEG, molecular masses of 2000, 4000 and 10000) indeed produces aqueous two-phase systems (ATPSs) at a temperature of 25 degrees C and atmospheric pressure . Ammonium bicarbonate is clearly not suitable as a phase-forming salt, because of its too-low solubility in water.

Eur J Cancer Prev, 1998 May, 7 Suppl 2, S75 - 8
Composition and control of ileal contents; Hill MJ; The nutrient supply to the colonic bacterial flora probably consists of 60-70 g fermentable substrate; up to 15 g may be protein and the remainder is carbohydrate . In addition, there may be 5 g long-chain fatty acid . The proximal colon is the main site of bacterial metabolism in the colon . However, the key problem is the inaccessibility of the caecum, and the difficulty of studying its ecology . In a stable ileostomy the last few centimetres of ileum take on the appearance of a colonic mucosa, and this model is the best that we have for the caecum . All methods of study are open to criticism, and it is essential that a variety of methods be used and constantly checked against the results of indirect measures.

Trends Cell Biol, 1998 Jun, 8(6), 219 - 21
Fermenting debate: do yeast undergo apoptosis?
Fraser A, James C.
Apoptosis is a common feature of multicellular organisms . However, the recent observations of non-metazoan cell deaths displaying morphology reminiscent of apoptosis has suggested the existence of an ancestral cell death machinery . We discuss this possibility and its implications for the use of yeast in the dissection of the metazoan apoptotic process.

Biotechnol Prog, 1998 Jul-Aug, 14(4), 561 - 6
Improved erythromycin production in a genetically engineered industrial strain of Saccharopolyspora erythraea; Minas W et al.; An industrial erythromycin production strain of Saccharopolyspora erythraea spp . was used to demonstrate that careful genetic engineering can significantly improve productivity . The chromosomally integrated Vitreoscilla hemoglobin gene (vhb) was shown to enhance the final titer of erythromycin by some 70% compared to the original S . erythraea spp . Overall, specific erythromycin yields were about 2.5 g of erythromycin/g of total protein for S . erythraea::vhb but <1 for the S . erythraea spp . The maximum rates of biosynthesis were 57.5 mg of erythromycin/(L/h) and 24.3 mg/(L/h) for the recombinant strain S . erythraea::vhb and S . erythraea spp., respectively . Overall space-time yield was 100% higher for the S . erythraea::vhb fermentation (1.1 g of erythromycin/(L/day)) than for the S . erythraea spp . fermentation (0 . 56 g of erythromycin/(L/day)) . The genetic stability of the recombinant strain was high, and no selective pressure was needed throughout the cultivations . Expression of functional Vitreoscilla hemoglobin throughout the cultivations was verified by CO difference spectrum assays.

J Mol Evol, 1998 Aug, 47(2), 211 - 21
Shaping of Drosophila alcohol dehydrogenase through evolution: relationship with enzyme functionality; Atrian S et al.; Drosophilidae is a large, widely distributed family of Diptera including 61 genera, of which Drosophila is the most representative . Drosophila feeding is part of the saprophytic trophic chain, because of its dependence upon decomposing organic matter . Many species have adapted to fermenting fruit feeding or to artificial (man-made) fermentation habitats, such as cellars and breweries . Actually, the efficient exploitation of niches with alcohols is considered one of the reasons for the worldwide success of this genus . Drosophila alcohol dehydrogenase (ADH), a member of the short-chain dehydrogenase/reductase family (SDR), is responsible for the oxidation of alcohols, but its direct involvement in fitness, including alcohol tolerance and utilization, gives rise to much controversy . Thus, it remains unclear whether ADH differentiation through evolution is somehow associated with natural adaptation to new feeding niches, and thus maybe to Drosophila speciation, or if it is a simple reflection of neutral divergence correlated with time separation between species . To build a hypothesis which could shed light on this dilemma, we analyzed the amino acid variability found in the 57 protein ADH sequences reported up to now, identified the taxon-specific residues, and localized them in a three-dimensional ADH model . Our results define three regions whose shaping has been crucial for ADH differentiation and would be compatible with a contribution of ADH to Drosophila speciation.

Regul Toxicol Pharmacol, 1998 Jun, 27(3), 200 - 3
Summary of the symposium establishing the safety of fat and macronutrient substitutes presented at the 33rd annual meeting of the Society of Toxicology, San Diego, California, March 13-17, 1994; Fix L et al.; Macronutrient substitutes (MNS) are food ingredients designed to replace the organoleptic and/or functional properties of macronutrients such as fats or sugars in processed foods . Because they may be consumed in large quantities daily, traditional methods of safety evaluation are inappropriate . Conventional safety factors cannot be used in extrapolating animal data to humans due to the limitations of administering very large doses of MNS to animals . The proper evaluation of the safety of MNS involves appropriate studies in animals and humans including comparative biodispositional studies, genotoxicity and cytotoxicity studies, reproductive and developmental studies, mechanistic studies, digestive and fermentation studies, nutritional studies, and studies involving humans with special focus on gastrointestinal function . Guidelines for the proper conduct of human studies were presented and these include the use of competent investigators and IRB-approved protocols and the use of adequate numbers of healthy male and female volunteers . Postmarketing surveillance is the final step in the safety evaluation process for macronutrient substitutes . It was concluded that MNS should be evaluated on a case-by-case basis.

Insect Biochem Mol Biol, 1998 May-Jun, 28(5-6), 309 - 19
Molecular adaptation of Drosophila melanogaster lysozymes to a digestive function; Regel R et al.; A lysozyme (pI 5.5) was purified to homogeneity from heated acid extracts of Drosophila melanogaster larvae, using gel filtration in a Superose column and ion-exchange chromatography in a Mono Q column . The final yield was 67% . The purified lysozyme with Mr 13,700 (determined by SDS-polyacrylamide gel electrophoresis) decreases in activity and has its pH optimum displaced towards acidic values and Km increases as the ionic strength of the medium becomes higher . The lysozyme is resistant to a cathepsin D-like proteinase present in cyclorrhaphous Diptera and displays a chitinase activity which is 11-fold higher than that of chicken lysozyme . Microsequencing of an internal peptide of the purified lysozyme showed that this enzyme is the product of the previously sequenced Lys D gene . The results suggest that the product of the Lys P gene has pI 7.2, a pH optimum around 5 and is not a true digestive enzyme . The most remarkable sequence convergence of D . melanogaster lysozyme D and lysozymes from vertebrate foregut fermenters are serine 104 and a decrease in the number of basic amino acids, suggesting that these features are necessary for digestive function in an acid environment . Adaptive residues putatively conferring stability in an acid proteolytic environment differ between insects and vertebrates, probably because they depend on the overall three-dimensional structure of the lysozymes . A maximum likelihood phylogeny and inferences from insect lysozyme sequences showed that the recruitment of lysozymes as digestive enzymes is an ancestral condition of the flies (Diptera: Cyclorrhapha).

Gut, 1998 Jun, 42(6), 799 - 806
Dietary fibre and intestinal microflora: effects on intestinal morphometry and crypt branching; McCullogh JS et al.; BACKGROUND: Fermentable dietary fibre has many effects on the gastrointestinal tract . One is to alter epithelial crypt cell proliferation, especially in the colon . A discrepancy between epithelial cell production rates and intestinal weights has been noted previously: crypt cell production rates only increase if bacterial fermentation occurs, but intestinal wet weight can increase in the same animals without bacterial fermentation of fibre . AIMS: To quantify intestinal cell populations in order to resolve the above paradox . METHODS: Conventional and germ-free rats were fed fibre-free or fibre supplemented diets and their intestines were quantified by morphometry . RESULTS: There was evidence of fibre associated muscle hypertrophy in the colon, but the main effect of fibre was an increase in the number of crypts per circumference and also the number of branched crypts in the proximal colon in both groups . There was also a large increase in the number of branched crypts in the mid colon of the germ-free rats (both fibre-free and fibre supplemented) . Fibre had a direct (bacteria independent) effect on goblet cells in the small intestine and a direct effect on the goblet cells in the colon, which was attenuated by the presence of bacteria . There was a notable decline in the number of enteroendocrine cells in the small intestine of the germ-free animals . CONCLUSIONS: Fibre has several direct and indirect effects on the gut . In the proximal colon it can directly increase the number of crypts present . This provides a means for increasing intestinal mass in addition to intestinal crypt cell production.

Acta Microbiol Pol, 1998, 47(1), 31 - 43
Purification of extracellular catalase from Aspergillus niger; Rogalski J et al.; The extracellular catalase (EC 1.11.1.6) produced by Aspergillus niger culture in 5-liter fermentor was isolated and purified by ion-exchange chromatography on DEAE Sepharose (fast flow) column, hydrophobic interaction on phenyl-Sepharose column and chromatofocusing on PBE 94 column . Some physico-chemical properties of two purified catalase forms were also determined (molecular weight, isolelectric point, polysaccharides contents, Km, and Ea).

Vet Q, 1998, 20 Suppl 3, S64 - 8
Weaning piglets, microbial fermentation, short chain fatty acids and diarrhoea; van Beers-Schreurs HM et al.; The effect of weaning on the absorptive capacity of the large intestine (LI) of weaned and unweaned pigs for short chain fatty acids (SCFA), sodium, potassium, and water has been determined by perfusion studies . Ligated loops were formed at four sites in the LI . In both groups the rate of absorption of SCFA, sodium and potassium was increased from the proximal to the distal sites, but this increase was not followed by an increase in the absorption of water . It is concluded that unweaned and weaned pigs can absorb SCFA and electrolytes immediately after weaning, but that a period of adaptation is required for the optimal absorption of water . This lower capacity for the absorption of water in the first two weeks after weaning makes the recently weaned pig vulnerable to a loss of fluid from the intestines.

Vet Q, 1998, 20 Suppl 3, S59 - 64
Non-starch polysaccharides in pig feeding; Bakker GC et al.; In pigs and humans, the nutrients starch, protein, fat and some minerals need to be digested prior to the terminal ileum for optimal use of these nutrients . In contrast, the non-starch polysaccharides (NSP) are mainly fermented by microbes in the hindgut . Results of experiments in pigs showed that NSP negatively affected apparent digestion of protein, fat and some minerals . In addition, large amounts of fermented NSP increased the empty weight of the hindgut . Because tissue of organs like the intestinal tract are metabolically very active, it may have required more energy for maintenance, hence leaving less energy for growth . Despite all the negative effects as mentioned above, including NSP-rich ingredients in pig diets also has quite a lot of advantages . Their energy supply can cover the energy requirements for maintenance . In addition, positive effects on the well-being and health of pigs, and on the excretion of ammonia are claimed . In conclusion, in future pig diet formulation not only the nutritional aspects of NSP-rich ingredients should be taken into account, but also their non-nutritional aspects . This might be realized by developing nutrient based feed evaluation systems, rather than the energy based systems which are presently used.

Vet Q, 1998, 20 Suppl 3, S52 - 9
Role of short-chain fatty acids in the hind gut; von Engelhardt W et al.; Short-chain fatty acids (SCFA) are produced by microbial fermentation in the hindgut in considerable amounts . Most of the anions in hindgut contents are SCFA, mainly acetate, propionate and butyrate . SCFA are rapidly absorbed . Mechanisms involved in the transepithelial transport are discussed . Besides the contribution to the overall energy metabolism of animals or men, SCFA have a number of further important effects on the colonic mucosa . Factors affecting the pH of compartments in the mucosa, cell swelling, stimulation of mucin release and of mucosal blood flow are mentioned . Controversial reports are known on the role of SCFA in the metabolism of colonocytes . In spite of the conflicting opinions on the interaction between SCFA metabolism and the development of colitis ulcerosa, diverticulosis and colorectal cancer seems to exist . The obscure differences between the effects of SCFA on cell proliferation, differentiation and apoptosis of colonocytes in vivo and in vitro indicate that besides direct effects of SCFA systemic effects such as neural and humoral factors are of crucial importance . The opposing effects of SCFA on proliferation and apoptosis in normal colonocytes and in colonic cancer cells may open possibilities for prevention and/or therapy of patients with colonic diseases.

Eur J Biochem, 1998 Jun 15, 254(3), 679 - 84
The porin RafY encoded by the raffinose plasmid pRSD2 of Escherichia coli forms a general diffusion pore and not a carbohydrate-specific porin; Andersen C et al.; The gene rafY from the plasmid pRSD2, which enables Escherichia coli to grow on raffinose, was transferred into expression plasmid pUSL77 . The protein was expressed in the porin-deficient Escherichia coli strain KS26 and was isolated and purified to homogeneity . The pure protein was reconstituted into lipid bilayer membranes . It formed an ion-permeable channel with a single-channel conductance of 2.9 nS of the open state in 1 M KCl, which is approximately twice of that of the general diffusion pores OmpF and OmpC of E . coli outer membrane . At lower pH the channel exhibited rapid flickering between three substates of the open channel . The RafY channel appears to be wide and water filled and has a small selectivity for cations over anions . Although RafY is part of an uptake and fermentation system for raffinose it does not contain a binding site for carbohydrates . Our results suggest that RafY is a general diffusion pore with a diameter, larger than that of the general diffusion porins OmpF and OmpC, that allows the diffusion of high-molecular-mass carbohydrates through the outer membrane.

Mycopathologia, 1997-98, 140(2), 99 - 103
Occurrence and toxigenicity of Fusarium moniliforme from freshly harvested maize ears with special references to fumonisin production in Egypt; Fadl Allah EM; Using the seed-plate technique, 18 different isolates of Fusarium moniliforme were isolated on pentachloronitrobenzene (PCNB) agar medium from 18 samples of a local variety of corn collected from locations in Minia Governorate . The isolates of F . moniliforme were screened for their ability to produce fumonisins on polished rice grains using the solid state fermentation technique . Based on thin layer chromatographic (TLC) analyses using silica gel plates, 14 of the 18 isolates tested produced FB1 and FB2 with Rf (0.17) and (0.24), respectively . Concentration of FB1 was estimated using high performance liquid chromatography (HPLC) . Production of FB1 by the 14 isolates of F . moniliforme tested ranged from 69 to 4495 ppm indicating that mouldy corn may represent a health hazard to consumers.

Jpn J Cancer Res, 1998 May, 89(5), 487 - 95
Chemoprevention of N-nitroso-N-methylurea-induced rat mammary cancer by miso and tamoxifen, alone and in combination; Gotoh T et al.; We examined the effects of a Japanese fermented soybean product, miso, and tamoxifen (TAM), alone and in combination, on N-nitroso-N-methylurea (MNU)-induced rat mammary cancer . Seven-week-old female CD/Crj rats received a single i.v . dose (50 mg/kg body weight) of MNU . After administration of MNU, the rats were divided into 4 groups: regular diet (control), 10% miso diet, regular diet + TAM, and 10% miso diet + TAM . TAM was implanted s.c . in the form of pellets containing 2.5 mg at the same time as MNU was administered . All rats were observed for 18 weeks after MNU administration . Incidence (percentage of rats with tumors) and multiplicity (mean tumors/rat) of mammary tumors were 91% and 4.5 in the control, 77% and 2.4 (P < 0.05) in the 10% miso group, 68% and 1.4 (P <0.01) in the TAM group, and 10% (P < 0.0001 or less) and 0.2 (P < 0.0001) in the 10% miso + TAM group . In the second experiment, the effect of the combination of miso and TAM on established rat mammary tumors was investigated . When the mammary tumors induced by MNU reached 10 to 25 mm, the rats were divided into 3 treatment groups: regular diet, regular diet + TAM, and 10% miso diet + TAM . At 6 weeks after the start of treatment, the mean tumor size in the control and TAM groups was 160% and 141% of the pretreatment value, but a decrease of 85% of the pretreatment value was produced by the combination of miso and TAM, and this was significantly different from both the control and TAM groups (P < 0.01) and P < 0.05, respectively) . These results indicate that miso is useful in protecting against mammary cancer and it can be expected to have a potent antitumor effect, especially when used in combination with TAM.

Appl Microbiol Biotechnol, 1998 Jun, 49(6), 725 - 31
A genetically engineered strain of Saccharopolyspora erythraea that produces 6,12-dideoxyerythromycin A as the major fermentation product
Stassi D, Post D, Satter M, Jackson M, Maine G.
The erythromycin producer, Saccharopolyspora erythraea ER720, was genetically engineered to produce 6,12-dideoxyerythromycin A, a novel erythromycin derivative, as the major macrolide in the fermentation broth . Inspection of the biosynthetic pathway for erythromycin would suggest that production of this compound could be achieved simply through the disruption of two genes, that encoding the erythromycin C-6 hydroxylase (eryF) and that encoding the erythromycin C-12 hydroxylase (eryK) . The double mutant, however, was found to produce a mixture of 6,12-dideoxyerythromycin A and the precursor, 6-deoxyerythromycin D . Complete conversion to the desired product (to the limit of detection by TLC) was achieved by inserting an additional copy of the eryG gene, encoding the erythromycin 3"-O-methyltransferase and driven by the ermE* promoter, into the S . erythraea chromosome.

J Dairy Sci, 1998 Jun, 81(6), 1619 - 23
Prediction of milk protein concentration from elements of the metabolizable protein system; Smoler E et al.; Elements of the metabolizable protein system in the United Kingdom were examined for their suitability as potential predictors of milk protein concentration . Models were based on data from 163 cows offered five forage mixtures for ad libitum intake plus concentrates at 3, 6, or 9 kg/d of dry matter . The models were then tested on a separate data set of 100 cows offered seven forage mixtures for ad libitum intake plus concentrates at 6 kg/d of dry matter . To minimize problems with collinearity, variables were arranged hierarchically; successive elements were components of variables at higher element levels . Variables from different element levels were not used in the same models . Models were constructed using ridge regression to minimize problems with collinearity . The fit and precision of prediction were generally poor because these models did not take into account animal variables . Models using undergradable dietary protein performed slightly better than did those using digestible undegraded protein . The use of slowly degradable protein and quickly degradable protein rather than rumen-degradable protein generally resulted in improvements in prediction . Models using neutral detergent fiber and quickly fermented carbohydrate were better than those using total carbohydrate . We concluded that there was little to be gained from using the elements of the metabolizable protein system considered here for the prediction of milk protein concentration.

Vaccine, 1998 May-Jun, 16(9-10), 960 - 8
Development of a mammalian cell (Vero) derived candidate influenza virus vaccine; Kistner O et al.; Influenza vaccine production is dependent on the availability of embryonated hen eggs for virus growth . This is an extremely cumbersome system with many disadvantages with respect to selection of virus variants and presence of adventitious viruses . We have developed an alternative cell culture system which allows rapid production of large volumes of vaccine . The World Health Organisation (WHO) approved Vero cell line was used in serum-free culture to grow a multitude of influenza strains to high titre . This system could be scaled-up to allow vaccine production with a 1200 litre fermenter volume . A purification scheme was developed which resulted in a high purity whole virus vaccine . This was demonstrated to be at least as immunogenic as a conventional egg-derived preparation in a mouse model.

Khirurgiia (Mosk), 1998, (6), 81 - 4
{The clinical picture and treatment of destructive pancreatitis}; Reshetnikov EA et al.; The results of treatment of 319 patients with acute pancreatitis are analyzed, 48 from them (15.1%)--with pancreanecrosis . Etiologic factors in destructive pancreatitis were alcohol addiction (41.67%), cholelithiasis (37.5%), hyperlipidemia (10.41%), hypercalcemia (4.17%), postoperative (4.17%) . Location of the necrosis in parapancreatic fat cellular tissue was detected in 6 patients, in pancreatic head--in 8 and both in pancreatic head and corpus--in 11, in corpus and in tail--in 10; total pancreo-necrosis was observed in 5 patients . Therapeutic measures were conservative and only in cholelithiasis cholecystectomy was performed as well as drainage of the choledochus and abdominal cavity . Intensive care was aimed at blocking pancreatic and gastric secretion, inhibition of pancreatic enzymes ferments and suppressing mediators of inflammation, immunocorrection, prophylaxis of infection in the necrotic tissues . Desintoxication was carried out by combination of infusion therapy with forced diuresis, usage of extracorporeal methods and laparoscopic sanation of the abdominal cavity with subsequent lavage . Surgical interventions were carried out in far-off period only for complications of pancreanecrosis . Mortality rate in pancreanecrosis made up 20.85% and in total number of patients with acute pancreatitis--3.13%.

Methods Mol Biol, 1998, 103, 193 - 208
Expression of tetanus toxin fragment C; Clare J et al.; 1 . The yield of fragment C was only modestly affected by Mut phenotype, and the site and type of integration event . 2 . Fragment C accumulation was closely correlated with gene dosage and maximal expression levels required high gene copy number . 3 . Yields were greatly increased in controlled fermenters, compared to shake-flasks, owing to the high cell density achieved and to an increased efficiency of induction (2.5- to 10-fold) . 4 . In fermenter inductions of a 14-copy strain, fragment C accumulated to 27% of total protein, giving an estimated yield of 12 g/L . 5 . Considerable clonal variation in the level of expression occurred with transplacement transformants, and this was owing to a diversity of different integration events and to differences in gene copy number . 6 . These multicopy transplacement events occur by in vivo circularization of transforming DNA fragments followed by repeated single-crossover integration . This is presumably a general phenomenon, such that it should be possible to obtain multicopy integrants from all P . pastoris transplacement transformations.

Methods Mol Biol, 1998, 103, 107 - 20
High cell-density fermentation; Stratton J et al.; The purpose of this chapter is to educate the reader about the basic equipment and strategies used in fermentations of P . pastoris in both bench-top and pilot-scale operations . A key element in expression of foreign proteins in this yeast is the need for sufficient aeration, which is achieved by proper mixing of the media and by blending gases to control dissolved oxygen content . Automatic pH control is essential for growth and expression in P . pastoris . Finally, fed-batch fermentations require the use of peristaltic pumps and tubing capable of low rates of delivery for the feeding of nutrients and base . Teflon tubing and peristaltic pump adapters are recommended for fed-batch operations . The information in this chapter should enable a reader with little or no experience to perform a high-cell density fermentation of a P . pastoris expression strain . Although most procedures described here are specifically for the BioFlo III (NBS), it should be possible to achieve high expression levels with almost any good-quality fermentor, modified to accommodate this organism.

J Chromatogr Sci, 1998 Jul, 36(7), 340 - 4
Quantitative analysis of thuringiensin by high-performance liquid chromatography using adenosine monophosphate as an internal standard; Liu CM et al.; An analytical method for thuringiensin using adenosine monophosphate (AMP) as an internal standard is established . AMP, with high stability and availability, is an appropriate internal standard for thuringiensin quantitative analysis using high-performance liquid chromatography and ultraviolet absorbance detection at 260 nm . A good correlation between the concentration of thuringiensin and the peak-area ratios of thuringiensin to AMP is demonstrated . From this general equation of linear regression line, the concentration of thuringiensin can be assessed in fermentation broth or semi-purified product.

Aliment Pharmacol Ther, 1998 Jun, 12(6), 499 - 507
Review article: short chain fatty acids in health and disease; Cook SI et al.; Short chain fatty acids (SCFAs) have been the subject of much research over the past few decades . They play a vital role in maintenance of colonic integrity and metabolism . They are produced when dietary fibre is fermented by colonic bacteria . SCFAs are avidly absorbed in the colon, at the same time as sodium and water absorption and bicarbonate secretion . Once absorbed, SCFAs are used preferentially as fuel for colonic epithelial cells and have trophic effects on the epithelium . Clinically, SCFAs have been studied as possible therapeutic agents in diversion colitis, ulcerative colitis, radiation proctitis, pouchitis and antibiotic-associated diarrhoea . Although some promising effects have been observed in uncontrolled studies, a specific therapeutic role for SCFAs remains to be defined . SCFAs may be the effector of the beneficial role of fibre in prevention of colon cancer.

Biochem Mol Biol Int, 1998 Jun, 45(2), 245 - 53
Effect of some physiological factors on nitrogenase activity and nitrogenase mediated hydrogen evolution by mixed microbial culture; Kumar A et al.; Fermentative H2 evolution, nitrogenase activity (acetylene reduction) and nitrogenase mediated H2 evolution was studied in free cells of mixed microbial population of H2 producers . At 3% glucose level, the cells produced 8.35 l H2/mol glucose utilized . The role of nitrogenase system in H2 generation was evident by derepressed nitrogenase activity (0.46 nmoles C2H4 produced/mg protein/h) under defined in vitro conditions . For maximum expression of the activity, the cells required preactivation under anaerobic conditions by incubating at 40 degrees C for 20-24 h with 0.2% glucose in the culture medium . At an O2 level of more than 0.25%, the acetylene reduction activity decreased significantly and could not be detected at a level of 20% . Nitrogenase activity development was higher at acetylene: inoculum ratio between 4.2-6.25 . H2 evolution was lower when the mixed cells were incubated under an atmosphere of 10% C2H2 and 5% CO gas . This decrease in H2 evolution was also evident at 2.5-6.5 mM NaNO3 and KNO3 concentrations in the liquid culture medium thus establishing more than 50% H2 evolution through nitrogenase.

Hindustan Antibiot Bull, 1996 Feb-Nov, 38(1-4), 12 - 31
Modelling Sporangiospore-yeast transformation of Dimorphomyces strain; Omoifo CO; Two types of buffered media, strictly defined-Ammonium sulphate-basal salts and complex Peptone-basal salts, were used for the cultivation of Dimorphomyces pleomorphis, one of two dimorphic fungi isolated from fermenting juice of soursop fruit, Annona muricata L . The growth count was taken every twenty-four hours . Transient morphologies were observed to change from sporangiospores through enlarged globose cells, to granular particles and eventually, polar budding yeast cells in the strictly defined medium at 15 degrees, 20 degrees, or 37 degrees C, but the complex medium casually terminally induced polar budding yeast cells and multipolar budding yeast like cells in between the growth phases, at 15 degrees and 20 degrees C, while mainly multipolar budding yeastlike morphology was observed at elevated temperature . There was obvious influence of nutritional factor or morphological expression (p < 0.01) . After analysis of variance, the growth data could not fit into predictive quadratic polynomial model because the organism's response curves were incongruent with basic assumptions of the model . Furthermore, a stepwise regression analysis gave very low coefficients of determination, r2, for the interactive combinations . They were therefore, considered unfit for the data . Construction of the pII-profiles led to inference being drawn from the chemiosmotic theory, polyelectrolyte theory to account for the behaviour in the buffered multiionic media . It was also thought that inherent cellular mitotic division and glycolytic activity led to a prelogarithmic growth response.

Hindustan Antibiot Bull, 1996 Feb-Nov, 38(1-4), 1 - 11
Dimorphic fungi isolated from spontaneously fermented juice of soursop, Annona Muricata L; Omoifo CO; Two new fungi isolated from fermenting juice of soursop Annona Muricata L., exhibited dimorphism . Aerobic hyphae were coenocytic bearing sporangia while vegetative filaments were septate . Growth in broth was in discrete units . Glucose--yeast extract-peptone broth inoculated with sporangiospores of strain C12 induced arthroconidiospores but it was yeast cells, yeastlike cells, pseudohyphae and pseudomycelia bearing blastospores when strain C13 was inoculated . On the other hand, soursop extract induced arthrospores and yeast cells, yeast like cells and blastospore-bearing pseudomycelia respectively with strain C12 and strain C13 inoculation . Physiological characteristics were distinct . Strain C12 fermented soluble starch and raffinose completely while strain C13 proved weak for both sugars but complete in glucose utilization . The two dimorphic strains along with Saccaharomyces latis were negative in inulin fermentation . The three strains assimilated all carbon and nitrogen sources tested and grew at 37 degrees C . Based on cultural, morphological and biochemical differences, a tentative genus, Dimorphomyces was created for the dimorphic strains . D . diastaticus strain C12 and D . pleomorphis strain C13 were thought to initiate spontaneous fermentation which was brought to completion along with S . latis strain C14.

J Environ Sci Health B, 1998 Jul, 33(4), 487 - 510
Performances of mesophilic anaerobic digestion systems treating poultry mortalities; Chen TH et al.; A closed-loop anaerobic digestion system consisting of a leachbed (LB) and an upflow anaerobic sludge blanket (UASB) was tested as an alternative for the disposal of poultry mortalities . This paper compares the performances of three LB-UASB treatment systems with different initial moisture contents in the LBs . Each LB was loaded with one chicken and 5, 10 or 18 liters of water . The LBs initially carried out he hydrolysis/acidification phase while the UASBs the methanogenesis phase . Due to repeated inoculation by the UASBs, the LBs with 10 and 18 liters of water started producing methane on day 5, while the one with 5 liters of water on day 19 . However, methane production rates were low before day 40 for the LB with 10 liters of water and day 60 for the other LBs . Methane production gradually improved as the LBs continued to receive ungranulated sludge from the UASBs . The LBs eventually became balanced methane reactors . Continued balanced fermentation in the LBs resulted in leachates with very low substrate concentrations that could no longer support high-rate methanogenesis in the UASBs . Consequently, methane production rates from the UASBs decreased quickly while that from the LBs reached peak levels . Cumulative methane production from each LB eventually exceeded that from its connecting UASB . After 118 days of digestion, 414, 437 and 470 liters of methane were produced from the three systems, respectively . Cumulative methane production from the LBs with 5 and 18 liters of water accounted for 63% of the total methane produced from their respective systems . The LB with 10 liters of water produced 75% of the total methane from that system . Methane yields ranged from 0.485 to 0.554 m3 (Kg TS)-1 . About 86% of the initial dry weight was biodegraded . All three systems performed very well with little operational problems . Overall, the systems that started with 10 liters of water in the LB performed the best . Strategy for enhancing system performances and implementing farm applications are discussed.

J Appl Microbiol, 1998 May, 84(5), 847 - 51
Influence of dietary acetylated peptides on fermentation and peptidase activities in the sheep rumen; Witt MW et al.; The predominant mechanism of peptide breakdown by rumen micro-organisms is aminopeptidase . Thus acetylation of the N-terminus of peptides inhibits their degradation by rumen micro-organisms in short-term incubations with rumen fluid in vitro . An experiment was undertaken to determine if adaptation of the rumen microbial population would take place when acetylated peptides were fed for a prolonged period, which would enable the microbial population to break down the protected peptides and thus decrease their nutritive value . Three adult sheep, fitted with permanent rumen cannulae, received a maintenance hay/concentrate diet to which was added, at each meal, 20 g of casein enzymic hydrolysate ('peptides') or 20 g of peptides previously treated with acetic anhydride . The diets were fed for 28 d in a 3 x 3 latin square and samples were taken during the last 7 d . Fermentation products and NH3 concentrations indicated that acetylated peptides remained less degradable than untreated peptides . There was a trend towards increased proteolytic activity with acetylated peptides, and dipeptidase activity increased by 18% and 28%, respectively, compared with untreated peptides and control treatments . Activity against N-acetyl-Ala2 also increased when acetylated peptides were fed, but it remained only 13% of the rate of Ala2 hydrolysis . No increase was found in the rate of ammonia production from acetylated peptides in animals receiving acetylated peptides--this rate was 26% of that found with untreated peptides--and acetylated peptides continued to persist for longer in the rumen than untreated peptides after feeding . Thus it was concluded that the rumen microbial population did not adapt to utilize acetylated peptides.

J Appl Microbiol, 1998 May, 84(5), 811 - 9
Karyotyping of Saccharomyces strains with different temperature profiles; Giudici P et al.; This study examined the karyotype, the fermentation performance and the optimum growth temperature (Topt) of 28 yeast strains all identified as species belonging to Saccharomyces sensu stricto . The strains were isolated from fermented musts, which had not been inoculated, at two temperature ranges: 20-40 degrees C and approximately 0-6 degrees C . The results demonstrated a correlation between the Topt and the chromosome organization . In particular, strains with Topt of less than 30 degrees C showed only two bands in the region between 365 and 225 kb, while those with a Topt greater than 30 degrees C had three bands in this size range . From a taxonomic viewpoint, the Topt is a better indicator for the Saccharomyces sp . than the ceiling temperature of 37 degrees C currently used to differentiate cryotolerant Saccharomyces bayanus and S . pastorianus from non-cryotolerant S . cerevisiae and S . paradoxus strains.

J Appl Microbiol, 1998 May, 84(5), 752 - 8
Intracellular distribution of amino acids in an slp1 vacuole-deficient mutant of the yeast Saccharomyces cerevisiae; Gent DP et al.; Amino acid pools were compared in a constructed diploid strain of Saccharomyces cerevisiae, SKD1, and a closely related strain, SKD2, carrying the slp1 mutation characterized by low pools of lysine and lacking a central vacuole . Cells of SKD2 grew more poorly than SKD1 but took up the same total amount of amino acids from the medium per cell although the profile differed between the two strains . Initially, the total pool was much higher in SKD1 than in SKD2 but the overall relative distribution between cytosol and vacuole was identical and mainly cytosolic even though the composition differed between the two strains . At the end of growth the amino acid concentration had increased and become predominantly vacuolar . Two days later the total pool in SKD1 had declined to the starting level but the intracellular distribution remained identical to that at the end of fermentation . The total concentration of amino acids in SKD2 continued to increase, particularly in the cytosol.

J Pediatr, 1998 Jul, 133(1), 95 - 8
Digestion of human milk oligosaccharides by healthy infants evaluated by the lactulose hydrogen breath test; Brand-Miller JC et al.; OBJECTIVE: We hypothesized that human milk oligosaccharides (HMO) would not be digested and absorbed in the infant small intestine . The purpose of the study was to quantify the extent of digestion by using the lactulose breath hydrogen test . STUDY DESIGN: Twenty-four healthy, breast-fed infants were studied in the home setting . Eight infants (mean age 5.2 months) who had a positive breath hydrogen response (rise > 20 ppm) to the unabsorbable sugar lactulose were given an equivalent load of HMO (0.7 to 1.0 gm/kg body weight) the following week . The breath hydrogen response to the HMO load was compared with that after lactulose by using a paired t test . RESULTS: In seven of the eight infants, a large proportion of the HMO load reached the large intestine and was fermented . In these infants, the mean +/- SEM area under the breath hydrogen curve after HMO (5135 +/- 1148 ppm.4h) was not significantly different from that after lactulose (4949 +/- 1278 ppm.4h, p = 0.7s . CONCLUSIONS: This study suggests that HMO resist digestion in the small intestine of most breast-fed infants and undergo fermentation in the colon . HMO may therefore be the source of breath hydrogen in breast-fed infants.

Proc Natl Acad Sci U S A, 1998 Jul 21, 95(15), 8520 - 5
Human thioredoxin reductase from HeLa cells: selective alkylation of selenocysteine in the protein inhibits enzyme activity and reduction with NADPH influences affinity to heparin; Gorlatov SN et al.; Human thioredoxin reductase (TR) contains selenocysteine (Secys) in a redox center {cysteine (Cys)-497,Secys-498} near the C-terminus . The essential role of Secys in TR isolated from HeLa cells was demonstrated by the alkylation studies . Reaction of native NADPH reduced enzyme with bromoacetate at pH 6.5 inhibited enzyme activity 99% . Of the incorporated carboxymethyl (CM) group, 1.1 per subunit, >90% was in CM-Secys-498 . Alkylation at pH 8 increased the stoichiometry to 1.6 per subunit with additional modification of the Cys-59, Cys-64 disulfide center . A minor tryptic peptide containing both CM-Cys-497 and CM-Secys-498 was isolated from enzyme alkylated at pH 6.5 or at pH 8 . Preparations of TR isolated from HeLa cells grown in a fermentor under high aeration contained selenium-deficient enzyme species that had 50% lower activity . Decreasing oxygen to an optimal level increased cell yield, and fully active TR containing one Se per subunit was present . Reduction of fully active enzyme with tris-(2-carboxyethyl) phosphine converted it from a low to a high heparin affinity form . The tris-(2-carboxyethyl) phosphine-reduced enzyme was oxygen-sensitive and lost selenium and catalytic activity unless maintained under strictly anaerobic conditions . This enzyme could be converted to an oxygen-insensitive species by addition of NADPH, indicating that bound pyridine nucleotide is important for enzyme stability . An induced enzyme conformation in which the essential Secys is shielded from oxidative damage could explain these effects.

Biochemistry (Mosc), 1998 Jun, 63(6), 619 - 24
New methods of protein purification . Expanded bed chromatography; Galaev IY; This review considers a new method of protein purification--expanded bed chromatography . The method is based on pumping of the mobile phase upwards through the column bed . The bed starts to expand at liquid flow rate above a critical value, and the gaps between the sorbent beads expand . The controlled distribution of bead size and weight results in a stable expanded bed, where separate beads are not completely immobile, but oscillate about some steady position . The mobile phase flow through such a column is similar to plug flow . The main advantage of expanded bed chromatography is that it enables protein recovery directly from particulate-containing feed stocks like cell homogenates or even fermentation broth, when extracellular proteins are purified . The successful examples of protein purification by expanded bed chromatography and the available commercial systems are presented . The standard equipment for liquid protein chromatography can be used in the expanded bed mode.

Food Addit Contam, 1998 Apr, 15(3), 270 - 9
Application of liquid chromatography-atmospheric pressure chemical ionization mass spectrometry and tandem mass spectrometry to the determination of volatile nitrosamines in dry sausages; Eerola S et al.; A high-performance liquid chromatographic-atmospheric pressure chemical ionization mass spectrometric method was developed for the determination of volatile nitrosamines in dry sausages . Tandem mass spectrometry was applied for the detection of N-nitrosopyrrolidine, N-nitrosodiethylamine and N-nitrosopiperidine . N-nitrosomethylamine was detected by using the selected ion monitoring mode . The occurrence of the four different nitrosamines was monitored in 27 dry sausage samples and a correlation was observed between N-nitrosopyrrolidine and biogenic amines . Nitroso compounds are thus not only formed in heated conditions but formation can also occur during ripening of dry sausages by reaction between residual nitrite and amines formed during the fermentation process.

Food Addit Contam, 1998 Apr, 15(3), 251 - 64
Acacia gum (Gum Arabic): a nutritional fibre; metabolism and calorific value; Phillips GO; Gum Arabic (Acacia gum, INS 414: E414) is extensively used as a food additive, but there is no regulatory or scientific consensus about its calorific value . It is a complex polysaccharide, primarily indigestible to both humans and animals, not degraded in the intestine, but fermented in the colon under the influence of microorganisms . Despite a range of animal studies, there are no usable data for humans which can quantify the utilizable energy of Gum Arabic . Estimates in the literature from animal experiments vary from 0 to 4 kcal/g . After certain allowances are made for the energy losses from volatile and gaseous fermentation products, an upper level of 2 kcal/g for rats has been set . The situation in man is demonstrably different, with greatly reduced amounts of such products, and the need to adapt for varying periods before Gum Arabic is attacked by colonic bacteria . In the absence of an agreed scientific assignment, the FDA in the USA insist upon 4 kcal/g in nutritional labelling, whereas in Europe, no value has been assigned to soluble dietary fibre, such as Gum Arabic . This review argues that based on present scientific knowledge only an arbitrary value can be used for regulatory purposes.

J Antibiot (Tokyo), 1998 May, 51(5), 464 - 70
A novel macrolactam-trisaccharide antifungal antibiotic . Taxonomy, fermentation, isolation, physico-chemical properties, structure elucidation and biological activity; Hegde VR et al.; A novel secondary metabolite SCH 42282 (1), with antifungal activity was isolated from the fermentation broth of a soil actinomycete identified as a Microtetraspora sp . The active compound was separated from the fermentation broth by butanol extraction and purified on a silica gel column and by multi-coil counter current chromatography . The compound was identified as a novel macrolactam trisaccharide related to SCH 38518 (4) . The structure was established by hydrolysis of the parent compound and spectroscopic studies of the acetate derivative . The compound is active against Candida spp . (Geometric Mean MIC's . 18 micrograms/ml) but less active SCH 42729 (3) . the disaccharide (Geometric Mean MIC's, > or = 10.7 micrograms/ml and SCH 38518 (4), the monosaccharide (Geometric Mean Mic's, 3.8 micrograms/ml.

J Antibiot (Tokyo), 1998 May, 51(5), 455 - 63
Cycloepoxydon, 1-hydroxy-2-hydroxymethyl-3-pent-1-enylbenzene and 1-hydroxy-2-hydroxymethyl-3-pent-1,3-dienylbenzene, new inhibitors of eukaryotic signal transduction; Gehrt A et al.; In a screening for new inhibitors of NF-KB and AP-1 mediated signal transduction pathways in COS-7 cells using secreted alkaline phosphatase (SEAP) as a reporter gene three novel compounds, cycloepoxydon (1), 1-hydroxy-2-hydroxymethyl-3-pent-1-enylbenzene (2) and 1-hydroxymethyl-3-pent-1,3-dienylbenzene (3) were isolated from fermentations of the deuteromycete strain 45-93 . Cycloepoxydon inhibits the TPA-induced NF-KB and AP-1 mediated SEAP expression with an IC50 of 1-2 micrograms/ml (4.2-8.4 microns) and 3-5 micrograms/ml (12.6-21 microns) respectively . 1-Hydroxy-2-hydroxymethyl-3-pent-1-enylbenzene (2) inhibits the TPA-induced NF-KB and AP-1 mediated SEAP expression with an IC50 of 7 micrograms/ml (36.4 microns) and 5 micrograms/ml (26 microns) . 3 showed only a weak inhibition of the AP-1 and no influence on NF-KB dependent reporter gene expression . In COS-7 and HeLa S3 cells electrophoretic mobility shift assays showed that cycloepoxydon strongly reduced the TPA and TNF- alpha mediated binding of NF-KB to a high affinity consensus sequence which was due to the inhibition of phosphorylation of the protein IKB.

Aliment Pharmacol Ther, 1997 Dec, 11(6), 1067 - 72
Absence of gaseous symptoms during ingestion of commercial fibre preparations; Zumarraga L et al.; BACKGROUND: While fibre is believed to cause gaseous symptoms, a study in healthy volunteers showed no increase in flatulence when the diet was supplemented with fermentable (psyllium) or non-fermentable (methylcellulose) fibre . However, extrapolation of this observation to subjects who use fibre is arguable since these individuals may have a propensity to gaseousness . In the present study, gaseous complaints during fibre ingestion were assessed in subjects who believed that a previous exposure to fibre induced gas . METHODS: In a double-blind protocol, subjects were randomized to one of four treatment periods, during which the regular diet was supplemented for 1-week periods with two daily doses of: placebo 10 g, psyllium 3.4 g, methylcellulose 2 g or lactulose 5 g . A symptom diary was maintained for 1-week periods on or off treatment . RESULTS: During treatment, the lactulose group passed gas significantly more often than did the psyllium or the methylcellulose group (P = 0.01) . No other symptom was significantly different among the treatment groups . CONCLUSIONS: (1) psyllium and methylcellulose did not cause greater gaseous symptomatology than did placebo in subjects who believed that these preparations caused gas; and (2) subjects commonly misidentify dietary components that cause gaseous symptoms.

Clin Ther, 1998 May-Jun, 20(3), 497 - 504
Effects of beano on the tolerability and pharmacodynamics of acarbose; Lettieri JT et al.; Acarbose is an alpha-glucosidase inhibitor approved for the treatment of type 2 diabetes mellitus . Acarbose inhibits carbohydrate digestion, allowing an excessive amount of undigested carbohydrate to reach the colon . Bacterial fermentation of the carbohydrate produces intestinal gas, which can cause flatulence and abdominal pain . Beano, an over-the-counter enzyme preparation (alpha-galactosidase), diminishes intestinal gas production by enhancing the breakdown of certain carbohydrates before they reach the lower intestine . This study was undertaken to investigate whether concomitant administration of Beano and acarbose could reduce the flatulence associated with acarbose and, if so, whether Beano would interfere with the effects of acarbose on postprandial serum glucose concentration . In this randomized, double-masked, placebo-controlled, three-period crossover study, 37 patients with type 2 diabetes mellitus received acarbose 100 mg, acarbose 100 mg plus Beano, or placebo . The study population consisted of 20 males and 17 females who ranged in age from 36 to 72 years (mean, 56 years) and in weight from 62 to 142 kg (mean, 92 kg) . Each treatment period consisted of 3 days, during which both acarbose and Beano were given at the beginning of each of three meals . There was a 4-day washout interval between each treatment period . The frequency and severity of flatulence were measured using a score compiled from patient diaries . As an additional measure of intestinal gas production, breath hydrogen concentration was measured on day 3 of each treatment period . Postprandial serum glucose concentration was measured at predetermined times after each morning dose to assess pharmacodynamic activity . Patients who took Beano with acarbose had a significantly lower flatulence score than did those who took acarbose alone (0.79 vs 1.09) . Consistent with this finding, breath hydrogen concentration was lower after administration of acarbose plus Beano than with acarbose alone (31.2 ppm vs 50.5 ppm) . Beano had variable effects on the ability of acarbose to reduce the postprandial serum glucose concentration . Although postprandial serum glucose levels were higher in patients who received acarbose plus Beano than in those who received acarbose alone, both treatments (with or without Beano) resulted in postprandial serum glucose levels that were significantly lower than those seen with placebo . Therefore, although Beano appeared to diminish the activity of acarbose, postprandial serum glucose concentrations still decreased significantly in patients taking Beano with acarbose . Beano has been shown to alleviate the flatulence accompanying acarbose treatment, but it may also interfere with the glucose-lowering effect of acarbose.

Curr Microbiol, 1998 Aug, 37(2), 94 - 100
Tindallia magadii gen . nov., sp . nov.: an alkaliphilic anaerobic ammonifier from soda lake deposits; Kevbrin VV et al.; Strain Z-7934, an alkaliphilic, obligately anaerobic, fermentative, asporogenous bacterium with Gram-positive cell wall structure, was isolated from soda deposits in Lake Magadi, Kenya . The organism ferments only a few amino acids, preferentially arginine and ornithine, with production of acetate, propionate, and ammonia . It is a true alkaliphile, with pH range for growth ranging from 7.5 to 10.5 (optimum pH 8.5), and growth is dependent on the presence of sodium ions . The G+C content of the genomic DNA is 37.6 mol% . 16S rDNA sequence analysis of strain Z-7934 shows that it belongs phylogenetically to cluster XI of the low G+C Gram-positive bacteria . On the basis of its distinct phylogenetic position and unique physiological properties, we propose a new genus and new species, Tindallia magadii, for this strain . The type strain is Z-7934(T) (=DSM 10318).

Food Chem Toxicol, 1998 May, 36(5), 445 - 9
A 4-year study of plasma ochratoxin A in a selected population in Tokyo by immunoassay and immunoaffinity column-linked HPLC; Ueno Y et al.; Employing a competitive ELISA (cELISA) based on monoclonal antibody and a novel immunoaffinity-column (IAC)-linked HPLC-fluorometry, ochratoxin A (OTA) levels in the plasma of 184 healthy volunteers (130 males, 54 females) were surveyed in Tokyo during the 4 years from 1992 to 1996 . It was found that 85% of the cases were positive for OTA except 38% in 1994, and an average value in the positives was estimated as 68 pg/ml . This suggests that the population in Tokyo is exposed to OTA at high frequency, although the level in plasma is far less than that reported in Europe and Canada . A partial contribution of fermented dietary foodstuffs, coffee and wine is suspected as the source of the OTA observed in the human plasma.

Cancer Res, 1998 Jul 1, 58(13), 2869 - 75
Mitochondrial membrane potential (delta psi(mt)) in the coordination of p53-independent proliferation and apoptosis pathways in human colonic carcinoma cells; Heerdt BG et al.; We have previously defined depressed mitochondrial function as a determinant in colon cancer risk and progression and established that metabolism of butyrate, a short-chain fatty acid generated during the fermentation of fiber by endogenous intestinal bacteria, induces mitochondrial function-dependent growth arrest and apoptosis of colonic carcinoma cells in vitro . Here, we dissect the relationships among mitochondrial function, growth arrest, and apoptosis, reporting that initiation and maintenance of butyrate-mediated p53-independent p21WAF1/Cip1 induction and subsequent G0/G1 arrest require an intact mitochondrial membrane potential (delta psi(mt)) and that the process of dissipation of the delta psi(mt) is then essential for initiation of a butyrate-induced apoptotic cascade . Thus, we hypothesize that mitochondria play a pivotal role in coordinating proliferation and apoptosis pathways, a coordination that must be tightly regulated in rapidly renewing tissues, such as the colonic mucosa.

J Anim Sci, 1998 Jun, 76(6), 1691 - 701
Performance and digestion by steers grazing tall fescue and supplemented with energy and protein; Elizalde JC et al.; We studied the effects of different levels of protein and energy supplementation on BW gains and sites of nutrient digestion in steers grazing the primary growth of endophyte-infected tall fescue (Festuca arundinacea Schreb cv . Kentucky 31) . Angus steers (n = 168; mean BW = 246.8 +/- 15.0 kg) grazed tall fescue without supplementation (C) or were supplemented with 1.4 kg/d of cracked corn (CC1), 1.4 kg/d of corn gluten feed (CGF1), 2.8 kg/d of CC (CC2), 2.8 kg/d of CGF (CGF2), or .7 kg/d of cornstarch and .7 kg/d of corn gluten meal (CS-CGM) during an 85-d period in a randomized complete block design . Supplemented steers (S) had a higher (P = .03) ADG than the control steers (.64 vs .74 kg/d) . There was an interaction (P = .02) between supplement type and level . Supplementation during the grazing period had no effect on subsequent feedlot ADG (average 1.3 kg/d) . In a digestion study, Angus x Simmental steers (n = 4; 412 +/- 20.4 kg) fitted with cannulas in the esophagus, rumen, and duodenum grazed tall fescue (C), C + 3.1 kg/d CGF, C + 3.1 kg/d of cracked corn (CC), or C + 1.4 kg/d CS-CGM over four experimental periods in a Latin square design . The ruminal ammonia nitrogen concentration tended to be higher (P < .09) in C than in CGF and in CC (21.9 vs 19.2 mg/dL), but ruminal pH and total VFA concentration did not differ among treatments . Forage OM intakes were lower (P < .05) in steers supplemented with CC or CGF (an average of 7,570 g/d) than in C (9,658 g/d) . Total OM intakes and digestibilities did not differ (P > .10) among treatments . Duodenal N flows and efficiencies of net ruminal microbial protein synthesis were not different (P > .10) among treatments . Supplementation of steers grazing primary growth of tall fescue improved animal gain but did not have a great effect on ruminal fermentation, OM digestion, or net ruminal microbial protein synthesis.

FEBS Lett, 1998 May 29, 428(3), 263 - 8
Purification and characterisation of a new hypothalamic satiety peptide, cocaine and amphetamine regulated transcript (CART), produced in yeast; Thim L et al.; Cocaine and amphetamine regulated transcript (CART) is a newly discovered hypothalamic peptide with a potent appetite suppressing activity following intracerebroventricular administration . When the mature rat CART sequence encoding CART(1-102) was inserted in the yeast expression plasmid three CART peptides could be purified from the fermentation broth reflecting processing at dibasic sequences . None of these corresponded to the naturally occurring CART(55-102) . In order to obtain CART(55-102) the precursor Glu-Glu-Ile-Asp-CART(55-102) has been produced and CART(55-102) was generated by digestion of the precursor with dipeptidylaminopeptidase-1 . All four generated CART peptides have been characterised by N-terminal amino acid sequencing and mass spectrometry . The CART peptides contain six cysteine residues and using the yeast expressed CART(62-102) the disulphide bond configuration was found to be I-III, II-V and IV-VI . When the four CART peptides were intracerebroventricularly injected in fasted mice (0.1 to 2.0 microg) they all produced a dose dependent inhibition of food intake.

Parassitologia, 1998 Jun, 40(1-2), 91 - 101
Unum facere et alterum non omittere: antimalarial strategies in Italy, 1880-1930; Fantini B; At the end of the XIXth Century the attitude towards malaria changed dramatically from fatalism and resignation to an active policy that made the eradication of the disease a possible objective . This dramatic change in the scientific political and cultural attitudes towards malaria was the result of two main phenomena: i) the impact of the scientific medicine and Pasteurian revolution on medicine and health policies, and ii) the discovery of the theoretical simplicity of the cycle of malaria transmission and of the possibility to interrupt it, by avoiding the contacts between people and the Anopheles mosquitoes . However, scientifically based strategies against malaria were in place before the discovery of the real causative agents and of the transmission cycle at the end of the XIXth century, as the origin of the scientific medicine had already produced a 'rationale' for local and national campaigns against malaria . According to Tommasi-Crudeli, for example, the cause of malaria was not a 'chemical compound', a 'miasma', but a 'living ferment', specific and autonomous . As a consequence, the aim of antimalarial measures was to eliminate the conditions indispensable to the multiplication of the specific ferment contained in the soil . The theory of malaria aetiology changed after the discovery of the transmission cycle by Ross and Grassi, but the general strategy remained the same: to eliminate one of the factors indispensable to the multiplication and diffusion of the agent . The detailed knowledge of the malaria transmission cycle made it possible to define the exact conditions which were alone responsible for the propagation of the disease and its persistence in the endemic areas . The theoretical linearity and the specificity of the 'Grassi's law' was decisive and produced a fundamental paradigmatic shift in the antimalarial policies . The essential point for the epidemiology and prophylaxis of malaria became to clarify the conditions which contribute to facilitate or to prevent the infection of the Anopheles.

J Mol Biol, 1998 Jul 3, 280(1), 117 - 27
Expression of an antibody fragment at high levels in the bacterial cytoplasm; Martineau P et al.; Recombinant antibody fragments expressed in the cytoplasm of cells have considerable practical potential . However in the reducing environment of the cytoplasm, the intradomain disulphide bonds are not formed and the fragments are unstable and expressed in low yields . Here we attempted to overcome these limitations . We first isolated an antibody single chain Fv fragment that binds and activates an inactive mutant beta-galactosidase . We then subjected the gene encoding the scFv fragment to random mutation in vitro by error-prone polymerase chain reaction, and co-expressed the mutant beta-galactosidase and mutant antibody fragments in lac- bacteria . By plating on limiting lactose, we selected for antibody mutants with improved expression, and after four successive rounds of mutation and selection, isolated an antibody fragment that is expressed in the bacterial cytoplasm with yields of 0.5 g/l in a shaker flask (A600 nm of 5.5) and 3.1 g/l (A600 nm=33) in a fermentor . Analysis of the mutant antibody fragments revealed that the disulphide bonds are reduced in the cytoplasm, and that the fragments could be denatured and renatured efficiently under reducing conditions in vitro . This shows that with a suitable method of screening or selection, it is possible to make folded and functional antibody fragments in excellent yield in the cytoplasm .

Trends Biotechnol, 1998 Jun, 16(6), 250 - 8
Current trends in 'artificial-nose' technology; Dickinson TA et al.; Basic principles derived from biological olfaction, such as combining semiselective sensor arrays with pattern recognition, have been used to develop instrumentation capable of broad-band chemical detection and quantification . Commercially available instruments are useful in areas including quality control in the food, beverage and fragrance industries, environmental monitoring, chemical-purity and -mixture analysis, and medical diagnostics . Ongoing research is aimed at the development of more-advanced instruments that are smaller, cheaper, faster and more stable and reliable . These second-generation instruments are likely to find an increasing number of applications, including the on-line monitoring of fermentation and other bioprocesses.

J Clin Microbiol, 1998 Jul, 36(7), 2135 - 7
Isolation and characterization of sorbitol-fermenting Shiga toxin (Verocytotoxin)-producing Escherichia coli O157:H- strains in the Czech Republic; Bielaszewska M et al.; Two sorbitol-fermenting (SF) Shiga toxin-producing Escherichia coli (STEC) O157:H- strains were isolated from patients with hemolytic-uremic syndrome in the Czech Republic in 1995 . Their phenotypic and genotypic characteristics and genomic DNA fingerprints were identical or closely related to those of SF STEC O157:H- strains isolated in Germany in 1988 to 1997 . This indicates that the Czech isolates belong to the SF STEC O157 clone which is widespread in Germany . It is the first finding of the clone outside Germany.

Plant Foods Hum Nutr, 1997, 51(4), 365 - 80
Effect of soy-fortification method on the fermentation characteristics and nutritional quality of fermented maize meal; Plahar WA et al.; Studies were conducted to develop an appropriate household/small-scale enterprise level technique for the production of soy-fortified fermented maize dough (or meal) by comparing different treatments, processing methods and fortification levels . The effects of fortification method of the Ghanaian traditional fermented maize dough with raw or heat-treated whole soybeans and full-fat soyflour at 0%, 10% and 20% replacement levels, on the rate of fermentation and product quality were investigated . Sensory characteristics, trypsin inhibitor activity, amino acid pattern, proximate composition and hot paste viscosity were used as the indices of quality . Addition of whole soybeans to maize before milling and fermentation reduced the fermentation time by 60% while increasing the protein content by 24% and 70% respectively for 10% and 20% levels of fortification . A significant improvement was also achieved in the amino acids pattern of the fortified dough . However, raw whole soybeans imparted an undesirable color and beany flavor and an appreciable concentration of trypsin inhibitor activity (TIA) to the dough . Boiling soybeans for 20 min before incorporation into the maize for milling and fermentation was found necessary for desirable flavor and low levels of TIA . Little or no changes in the pasting viscosity characteristics occurred in samples containing boiled soybeans, while the usual method of fortifying maize meal with soy flour was found to severely depress the pasting viscosity characteristics and drastically reduced the acidity of the fermented dough . Based on the findings of the study, the most appropriate technique for the production of soy-fortified high protein fermented maize dough has been suggested to involve incorporation of boiled whole soybeans in soaked maize before milling and fermentation for improved sensory characteristics, enhanced nutritive value and optimal functional properties.

Appl Microbiol Biotechnol, 1998 May, 49(5), 579 - 83
The effects of space flight on the production of monorden by Humicola fuscoatra WC5157 in solid-state fermentation; Lam KS et al.; The effect of space flight on the production of the antibiotic monorden on two types of agar media, T8 and PG, by Humicola fuscoatra WC5157 was examined on board the US Space Shuttle mission STS-77 in May 1996 . Paired space-flight and ground control samples were prepared using identical hardware, protocol, media, and inoculum . Inoculation occurred simultaneously for both groups 2.5 after launch . The flight and ground samples were allowed to grow for the entire 10-day mission in a dark, thermally controlled (22 degrees C) environment . Post-flight HPLC analysis of the flight and ground sample extracts indicated that the production of monorden by H . fuscoatra WC5157 in the flight samples was higher than in the ground samples in both agar media . In the T8 medium, the production of monorden in the flight and ground samples was 11.6 +/- 3.5 micrograms and 8.9 +/- 1.1 micrograms respectively (30% increase) . In the PG medium, the production of monorden in the flight and ground samples was 23.8 +/- 3.3 micrograms and 8.2 +/- 2.2 micrograms respectively (190% increase) . The production of monorden in the flight and ground control samples was confirmed by HPLC-MS analysis.

Appl Microbiol Biotechnol, 1998 May, 49(5), 511 - 6
Ethanol production using nuclear petite yeast mutants; Hutter A et al.; Two respiratory-deficient nuclear petites, FY23 delta pet191 and FY23 delta cox5a, of the yeast Saccharomyces cerevisiae were generated using polymerase-chain-reaction-mediated gene disruption, and their respective ethanol tolerance and productivity assessed and compared to those of the parental grande, FY23WT, and a mitochondrial petite, FY23 rho(0) . Batch culture studies demonstrated that the parental strain was the most tolerant to exogenously added ethanol with an inhibition constant, Ki, of 2.3% (w/v) and a specific rate of ethanol production, qp, of 0.90 g ethanol g dry cells-1 h-1 . FY23 rho(0) was the most sensitive to ethanol, exhibiting a Ki of 1.71% (w/v) and qp of 0.87 ethanol g dry cells-1 h-1 . Analyses of the ethanol tolerance of the nuclear petites demonstrate that functional mitochondria are essential for maintaining tolerance to the toxin with the 100% respiratory-deficient nuclear petite, FY23 delta pet191, having a Ki of 2.14% (w/v) and the 85% respiratory-deficient FY23 delta cox5a, having a Ki of 1.94% (w/v) . The retention of ethanol tolerance in the nuclear petites as compared to that of FY23 rho(0) is mirrored by the ethanol productivities of these nuclear mutants, being respectively 43% and 30% higher than that of the respiratory-sufficient parent strain . This demonstrates that, because of their respiratory deficiency, the nuclear petites are not subject to the Pasteur effect and so exhibit higher rates of fermentation.

J Nutr, 1998 Jul, 128(7), 1192 - 8
Intestinal fermentation lessens the inhibitory effects of phytic acid on mineral utilization in rats; Lopez HW et al.; The specific effects of phytic acid (PA) and resistant starch (RS) on mineral bioavailability, namely, Ca, Mg, Fe, Zn and Cu, were investigated in rats adapted to semipurified diets . The diets provided either 73 g/100 g digestible wheat starch (DS) alone, or 53 g/100 g DS plus 20 g/100 g crude potato starch (RS) and either 0 or 1.1 g/100 g PA . A period of 3 wk was first planned to adapt the rats to their respective diets . Compared with rats fed the DS diets, those fed the RS diets had significant cecal hypertrophy and an accumulation of short-chain fatty acids, together with greater cecal blood flow . RS enhanced the cecal absorption of Ca and Mg (from 0.15 to 0.55 micromol/min for Ca, and from 0.10 to 0.35 micromol/min for Mg) . Mineral balance was enhanced significantly by RS (Ca, +46%; Mg +50%; Fe +20%; Zn, + 33% and Cu, +61%) . PA had no significant effect on Ca or Mg solubility and absorption in the cecum, and it failed to alter significantly Ca or Mg balance . The apparent absorption of Fe, Zn and Cu was significantly lower in rats fed the DS + PA diet than in rats fed the DS diet (Fe, -35%; Zn, -28%; and Cu, -31%) . In rats adapted to the RS diet, the inhibitory effects of PA were practically abolished and the mineral balance was restored to the control values . We conclude that the negative effects of PA on mineral balance are relatively minor compared with the stimulatory effect of RS.

J Nutr, 1998 Jul, 128(7), 1186 - 91
Feeding diets containing high levels of milk products or cellulose decrease urease activity and ammonia production in rat intestine; Kim KI et al.; Three studies were done to determine the effect of feeding diets containing high levels of a readily fermentable carbohydrate (lactose in milk or yogurt, or pure lactose) or an undigestible, unfermentable diluent (alpha-cellulose) on urease (EC 3.5.1.5) activity and net ammonia production in the rat gastrointestinal (GI) contents . Rats (170-200 g) were fed a control diet or diets containing 55% dried milk or 55% dried yogurt, 25% lactose or 10% alpha-cellulose . Feeding diets containing milk or yogurt decreased urease activity to approximately 11% of the control value in the small intestine (on the basis of grams of collected contents or total contents), and to 50% in the large intestine (only on the basis of grams of collected contents) . Feeding the diet containing 25% lactose also decreased urease activity (on the basis of grams of collected contents or total contents) to about 20% of the control value in the small intestine, but not (P > 0.05) in the large intestine . Net ammonia production rate was correlated (r2 = 0.98) with urease activity in the large intestinal contents, and the rate of ammonia production from ureolysis represented about two thirds of the total . Feeding the cellulose diet decreased (P < 0.05) both urease activity and net ammonia production in the large intestine to approximately 30% of the control value . Weights of tissue and contents of the large intestine were much higher (P < 0.01) in rats fed diets containing milk products or lactose than in the control rats, but were not affected by consumption of the cellulose diet . Results of our studies indicate that feeding diets containing high levels of milk products (lactose) or cellulose reduces urease activity and net ammonia production in the rat intestine, and thus may be beneficial for improving animal and human health.

Biochemistry, 1998 Jun 30, 37(26), 9266 - 73
Contribution of domain interface residues to the stability of antibody CH3 domain homodimers; Dall'Acqua W et al.; Dimers of CH3 domains from human IgG1 were used to study the effect of mutations constructed at a domain-domain interface upon domain dissociation and unfolding, "complex stability" . Alanine replacement mutants were constructed on one side of the interface for each of the sixteen interdomain contact residues by using a single-chain CH3 dimer in which the carboxyl terminus of one domain was joined to the amino terminus of the second domain via a (G4S)4 linker . Single-chain variants were expressed in Escherichia coli grown in a fermentor and recovered in yields of 6-90 mg L-1 by immobilized metal affinity chromatography . Guanidine hydrochloride-induced denaturation was used to follow domain dissociation and unfolding . Surprisingly, the linker did not perturb the complex stability for either the wild type or two destabilizing mutants . The CH3 domain dissociation and unfolding energetics are dominated by six contact residues where corresponding alanine mutations each destabilize the complex by >2.0 kcal mol-1 . Five of these residues (T366, L368, F405, Y407, and K409) form a patch at the center of the interface and are located on the two internal antiparallel beta-strands . These energetically key residues are surrounded by 10 residues on the two external beta-strands whose contribution to complex stability is small (three have a Delta DeltaG of 1.1-1.3 kcal mol-1) or very small (seven have a Delta DeltaG of </=0.7 kcal mol-1) . Thus, at the center of the CH3 structural interface there is a small "functional interface" of residues that make significant contributions to complex stability.

Biosci Biotechnol Biochem, 1998 May, 62(5), 953 - 8
Direct formation of human interleukin-11 by cis-acting system of plant virus protease in Escherichia coli; Takahashi T et al.; To produce a large amount of recombinant proteins in Escherichia coli, we constructed a unique cis-acting expression system using a plant virus protease . This new expression system could directly produce recombinant proteins, that had a biologically active form . A gene of nuclear inclusion-a (NIa), which had a specific amino acid sequence, was fused with a foreign protein gene at the same protein reading frame . One of the NIa-specific cleavage amino acid sequences, Gln-Ala, was also contained at the protein-protein junction . In the case of human interleukin-11 (hIL-11), a 23-kDa specific signal band was obtained from recombinant bacteria . N-terminal sequencing of the 23-kDa protein showed that NIa specifically cleaved the fusion protein at Gln-Ala, producing Ala-hIL-11 . Furthermore, we could produce the mature rhIL-11 by extending the culture time . This 23-kDa protein had the same biological activity as hIL-11 in a mouse plasmacytoma, T1165 . Combined with fermentation control, we produced mature rhIL-11 in E . coli.

Biosci Biotechnol Biochem, 1998 May, 62(5), 837 - 41
Effects of difructose anhydride III on calcium absorption in small and large intestines of rats; Suzuki T et al.; Difructose anhydride III (DFA III; di-D-fructo-furanose 1,2':2,3' dianhydride) was prepared from inulin with Arthrobacter sp . H65-7 inulin fructotransferase (depolymerizing (inulase II; EC 2.4.1.93) . DFA III is not hydrolyzed by enzymes in the small intestine, but is metabolized by microorganisms in the large intestine . We investigated the effects of DFA III on calcium absorption in two experiments . In the in vivo experiment, we examined the effects of DFA III, fructooligosaccharides, and raffinose on calcium absorption in male Sprague-Dawley rats 5 weeks old at start of the experiment and given feed containing 3% of one of these oligosaccharides for two weeks . The apparent calcium absorption was significantly higher in rats fed any of these oligosaccharides than in control rats, and the increase with DFA III was the greatest . Absorption in both the small and large intestines was affected . In rats fed DFA III, the cecal wall thickened and soluble calcium and the amounts of some organic acids were higher than in the control groups . In an in vitro experiment with everted jejunal and ileal sacs of rats, calcium absorption was higher when DFA III was present in the mucosal fluid at all concentrations tested (up to 200 mM) . In the jejunal sacs, the increase in calcium absorption depended on the DFA III concentration . In the ileal sacs, the absorption was maximum at 50 mM DFA III and did not increase further at higher concentrations . These results indicate that intact DFA III stimulates calcium absorption in the small intestine, and that cecal fermentation of DFA III may contribute to the increase in calcium absorption by the large intestine.

Methods Cell Biol, 1998, 57, 219 - 27
Laboratory scaleup of cell cultures (0.5-50 liters); Mather JP; With the modern tools of molecular and cell biology now available, many researchers find the need to scale up cell culture in order to produce large quantities of cells or conditioned medium for the further purification of proteins or subcellular fractions . The method used for scaleup will depend on the properties of the cell being used, the amount of material desired, the number of times the process is to be run, and the resources available . Roller bottles, microcarrier cultures, and hollow fiber cultures provide appropriate and scaleable growth systems for attachment-dependent cells . However, the most efficient production of material, especially if the large-scale production is to be repeated several times, is obtained by suspension adapting the cells and growing them in suspension . This can be done in spinners or in fermenters, which range in size from 0.1 to 12,000 liters in volume . This chapter describes methods for choosing the optimal production system and medium for scaling up to different levels of production and for suspension adapting cells for scaleup of suspension culture.

Med J Aust, 1998 Jun 1, 168(11), 552 - 5
Haemolytic-uraemic syndrome outbreak caused by Escherichia coli O111:H-: clinical outcomes; Henning PH et al.; In South Australia in 1995, we treated 20 children with haemolytic-uraemic syndrome associated with Escherichia coli O111:H- . The source of the outbreak was contaminated locally produced semi-dry fermented sausage (mettwurst) . One child died of multiple haemorrhagic cerebral infarcts . Eighteen children required renal dialysis (for a median of 14 days); 12 months after discharge five still had significant impairment of renal function . Other major complications included colonic necrosis (3), cerebral haemorrhage/infarction (3), convulsions (4), and glucose intolerance (2) . Although E . coli O111:H- has been associated with sporadic cases of haemolytic-uraemic syndrome, this was the first large outbreak reported in Australia.

Microbiology, 1998 Jun, 144 ( Pt 6), 1565 - 73
Phytase activity of anaerobic ruminal bacteria; Yanke LJ et al.; Phytase catalyses the release of phosphate from phytate (myo-inositol hexakisphosphate), the predominant form of phosphorus in cereal grains, oilseeds and legumes . The presence of phytase activity was investigated in 334 strains of 22 species of obligately anaerobic ruminal bacteria . Measurable activities were demonstrated in strains of Selenomonas ruminantium, Megasphaera elsdenii, Prevotella ruminicola, Mitsuokella multiacidus and Treponema spp . Strains isolated from fermentations with cereal grains proved to have high activity, and activity was particularly prevalent in S . ruminantium, with over 96% of the tested strains being positive . The measured phytase activity was found exclusively associated with the bacterial cells and was produced in the presence of approximately 14 mM phosphate . The most highly active strains were all S . ruminantium, with the exception of the one Mitsuokella multiacidus strain examined . Phytase activity varied greatly among positive strains but activities as high as 703 nmol phosphate released (ml culture)-1 were measured for a S . ruminantium strain and 387 nmol phosphate released (ml culture)-1 for the Mitsuokella multiacidus strain.

Curr Microbiol, 1998 Jul, 37(1), 1 - 5
High-frequency DNA rearrangements in the chromosomes of clinically isolated Mycoplasma fermentans; Hu WS et al.; Mycoplasma fermentans is currently being examined as an agent potentially associated with human disease . Several strains of M . fermentans were isolated from patients with respiratory tract disease and AIDS . Two of these clinical strains, M64 and SK6, were triple-filter-cloned and designated as the parental clones in this study . Genomic DNA of randomly picked subclones in four and five subsequent generations passed from the parental M64 and SK6 clones were analyzed by using a radiolabeled M . fermentans-specific insertion sequence (IS)-like element as the probe . The hybridization patterns of DNA restriction fragments revealed high frequencies of chromosomal changes accompanied with excision or new insertion of the IS-like element in M . fermentans chromosome . The findings indicate M . fermentans has an effective mechanism(s) to produce a rapid gene rearrangement that may be mediated by one or more copies of the IS-like element.

Exp Physiol, 1998 May, 83(3), 397 - 408
Gas handling in the caecum of the horse; Cottrell DF et al.; Electromanometric recordings of caecal pressures were made in chronically cannulated ponies . Endoscopy allowed direct observation of the caecal base and cupola while recording intracaecal pressures and enabled a functional interpretation of caecal pressure profiles . Using gas-tight seals, the caecal gas cap baseline pressure (tone) was usually below atmosphere, becoming less negative postprandially . Diurnal variations were observed in the amplitude and frequency of caecal pressure profiles and the direction of caecal movements, during which intra-caecal gas cap pressures briefly became positive . A paraprandial (psychic) phase of enhanced caecal motility was observed . Manipulation of the caecal gas cap volume, by insufflation of nitrogen gas, demonstrated the capacity of the caecal base to regulate gas pressures and to eliminate fermenting gases.

Arch Tierernahr, 1998, 51(1), 63 - 75
The effect of sealing and of additives on the fermentation characteristics and mould and yeast counts in stretch film wrapped big-bale lucerne silage; Keller T et al.; The effect of number of film layers was investigated in silages produced in wrapped big bales . The herbage used was difficult to ensile lucerne wilted to DM levels of 320-490 g/kg . Fermentation changed to a more homofermentative process as the number of film layers increased . An increasing number of film layers (4, 6, 8 or 10) also resulted in a notable decrease in moulds and yeasts . Four layers could not guarantee successful preservation in lucerne, and higher numbers of undesirable micro-organisms were detected . Hard stalks damaged the first two film layers during wrapping in the bales . Effect of number of film layers was more important than effect of additives for inhibition of mould and yeast counts.

Arch Tierernahr, 1998, 51(1), 21 - 6
The effect of porcine bile acids on methane production by rumen contents in vitro; Immig I; Hindgut fermentation differs from rumen fermentation by a lower methane production and the presence of reductive acetogenesis . Bile acids which are lost into the lower digestive tract may have a promoting effect on reductive acetogenesis in the hindgut . In this experiment it was investigated if bile acids induce reductive acetogenesis in rumen fermentation in vitro . Rumen contents from a fistulated cow were incubated in vitro with ground hay and increasing amounts of porcine bile acids or bile acid salts . Bile acids inhibited methane production up to 70% of the control incubation . The concomitant increase in propionate production compensated for the lower methane production so that the 2H-recoveries were in a normal range between 79-92% . Therefore the occurrence of reductive acetogenesis could be excluded . It is concluded, that bile acids are a controlling factor in caecal methanogenesis.

J Basic Microbiol, 1998, 38(2), 123 - 8
Continuous ethanol production from sugarcane molasses using a column reactor of immobilized Saccharomyces cerevisiae HAU-1; Sheoran A et al.; A fermentation system for the continuous ethanol production from sucrose and molasses using calcium alginate immobilized Saccharomyces cerevisiae strain HAU-1 has been optimised . Immobilization of active yeast cells (30%, w/v) was accomplished in 1.5% calcium alginate and these yeast-beads were employed for ethanol production in a vertical column reactor . High ethanol productivity was achieved with a medium containing 10%, w/v sucrose at a dilution rate of 0.20 h-1 . Alginate beads containing 30-50% yeast cell--mass resulted in high productivity 60.4 g l-1 h-1) . Sugarcane molasses containing 15% total sugars was fermented in column reactor to produce 6.0%, v/v ethanol in continuous system . These yields could be improved to 7.0% with overall 11% increase in fermentation--efficiency with the use of acid-clarified sugar cane molasses medium.

Biotechnology (N Y), 1996 Feb, 14(2), 192 - 6
High level secretion of a humanized bispecific diabody from Escherichia coli; Zhu Z et al.; Clinical development of bispecific antibodies (BsAb) has been effectively stymied by the lack of efficient production methods . We therefore attempted to produce a humanized BsAb fragment using an expression system that has proved very successful for secretion of monospecific Ab fragments from E . coli . An anti-p185HER2/anti-CD3 BsF(ab')2 was first recast into the diabody format and then periplasmically secreted from E . coli grown to high cell density in a fermentor . The diabody was recovered in very high yield (up to 935 mg/l) after protein A purification and predominantly (> or = 80%) as a dimer as judged by size exclusion chromatography . Diabody dimers were found to be mainly functional heterodimers (approximately 75%) by titration with p185HER2 extracellular domain . The diabody binds p185HER2 extracellular domain and human T lymphocytes with affinities close to those of the parent BsF(ab')2 . Furthermore, the diabody is capable of simultaneous binding to tumor cells overexpressing p185HER2 and CD3 on T cells as shown by cellular rosetting . The diabody is equally potent as the parent BsF(ab')2 in retargeting IL-2 activated T-enriched peripheral blood lymphocytes to lyse tumor cells overexpressing p185HER2.

Biochem Mol Biol Int, 1998 Jun, 45(1), 11 - 23
Free radical scavenging activity of fermented papaya preparation and its effect on lipid peroxide level and superoxide dismutase activity in iron-induced epileptic foci of rats; Imao K et al.; Fermented papaya preparation is a natural health food that has been commercially sold in Japan for 2 years . It is made by yeast fermentation of Carica Papaya Linn . We examined the antioxidant action of the fermented papaya preparation on free radicals and lipid peroxidation . Free radicals have been related with aging and diseases, such as cancer, diabetes and especially in neurological disorders, for example, Parkinson's disease or Alzheimer's disease . A diet including variable antioxidant foods may therefore help to prevent these illnesses . The free radical scavenging activity of the fermented papaya preparation was examined using an electron spin resonance (ESR) spectrometer . Fermented papaya preparation (50 mg/ml) scavenged 80% of hydroxyl radicals (.OH) as spin adducts of spin trap, 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) (5.27 x 10(15)spins/ml) generated by Fenton reagents . The value of IC50 was 12.5 mg/ml . The oral administration of the fermented papaya preparation for 4 weeks decreased the elevated of lipid peroxide levels in the ipsilateral 30 min after injection of iron solution by iron into the left cortex of rats . The fermented papaya preparation also increased superoxide dismutase activity in the cortex and hippocampus of them . These results suggest that the fermented papaya preparation has antioxidant actions and that it may be prophylactic food against the age related and neurological diseases associated with free radicals.

Arch Biochem Biophys, 1998 Jun 1, 354(1), 57 - 64
Aldehyde dehydrogenase (CoA-acetylating) and the mechanism of ethanol formation in the amitochondriate protist, Giardia lamblia; Sanchez LB; The so far unelucidated pathway of formation of ethanol, one of the major end products of the fermentative metabolism of the amitochondriate protist, Giardia lamblia, was examined . Two NAD-dependent enzymatic activities, an acetaldehyde dehydrogenase (CoA-acetylating) (EC 1.2.1.10) and an alcohol dehydrogenase (EC 1.1.1.1) were detected . These are assumed to catalyze the formation of ethanol from acetyl-CoA via acetaldehyde . The first activity, present on a 95-kDa protein, was purified . It catalyzed the reversible interconversion of acetyl-CoA to acetaldehyde and CoA-SH with NAD but not NADP as cofactor . In the direction of aldehyde formation acetyl-CoA was the preferred substrate . Propionyl-CoA and isobutyryl-CoA were reduced with lower efficiency while succinyl-CoA and benzoyl-CoA were not . In the direction of acyl-CoA formation, acetaldehyde was the preferred substrate . Propionaldehyde and isobutyraldehyde were utilized at a lower efficiency while formaldehyde, benzaldehyde, and acetone were not . The second activity, a primary alcohol dehydrogenase, was also NAD-specific and used preferentially ethanol as substrate . Sequencing data of peptides from the purified protein and Northern and Southern analysis indicated that the same polypeptide, which belongs to the bifunctional aldehyde/alcohol dehydrogenase enzyme family, carried both activities . These activities define the pathway to ethanol in G . lamblia as a two step-processes: (i) acetyl-CoA + NADH<-->acetaldehyde + CoA-SH + NAD+ and (ii) acetaldehyde + NADH<-->ethanol + NAD+ . In contrast to most eukaryotes in which ethanol formation proceeds from pyruvate via acetaldehyde, the G . lamblia pathway departs from acetyl-CoA, a more distal product of extended glycolysis.

Mol Cell Probes, 1998 Apr, 12(2), 85 - 92
The ftsZ gene as a tool for detection of Mycoplasma fermentans; Ofir R et al.; Mycoplasma fermentans was reported as a common contaminant of cell cultures, and was shown to either induce or suppress several immunological functions . A strain of M . fermentans was recently isolated from a mouse T-lymphoma cell line, which differs from other M . fermentans strains by its growth characteristics and was designated (in the authors' records) as strain 609 . Using the differential display technique (DD), a differentially expressed gene that was identified as the M . fermentans 609 ftsZ gene was isolated . Comparison of the nucleotide sequence of the M . fermentans 609 ftsZ gene to other ftsZ genes showed a 98% homology with Mycoplasma fermentans strain K7 and approximately 50% homology with Mycoplasma pulmonis and Mycoplasma genitalium . Comparison of the putative amino acid sequences of the FtsZ proteins showed similar homology . A polymerase chain reaction (PCR) assay to detect the presence of this ftsZ gene was established; it is a fast and convenient assay to detect infection of cells by the M . fermentans species . This work demonstrates that: (i) DD can be used as a useful technique to identify and isolate mycoplasmal genes from infected cells; and (ii) the ftsZ gene can be a useful marker to distinguish between different species of mycoplasma.

Poult Sci, 1998 Apr, 77(4), 552 - 6
Fermentation of soybean meal with Aspergillus usamii reduces phosphorus excretion in chicks; Hirabayashi M et al.; Fermentation with Aspergillus usamii almost completely degrades phytate phosphorus in soybean meal . Phosphorus excretion was investigated in chicks fed a fermented soybean meal-based diet . Thirty chicks were fed one of three experimental diets; a control soybean meal-based diet (total phosphorus, 5.2 g/kg; nonphytate phosphorus, 2.3 g/kg), a control soybean meal-based diet with added inorganic phosphorus (total phosphorus, 7.1 g/kg; nonphytate phosphorus, 4.0 g/kg), or a fermented soybean meal-based diet without supplemental inorganic phosphorus (total phosphorus, 5.8 g/kg; nonphytate phosphorus, 3.9 g/kg) for 4 wk . Body weight gain, the amount of retained phosphorus, and femoral phosphorus content were lower in the control group than in the phosphorus-supplied group and the fermented soybean meal group . The latter two groups showed similar body weight gain and femoral phosphorus content . On the other hand, phosphorus excretion was markedly more in the phosphorus-supplied group than in the other groups . As a result, phosphorus retention (percentage of intake) was lower in the phosphorus-supplied group than in the fermented soybean meal group . In conclusion, fermentation improved phosphorus bioavailability in soybean meal and supplemental inorganic phosphorus was not necessary for the fermented soybean meal-based diet, which remarkably reduced phosphorus excretion.

Nat Biotechnol, 1996 May, 14(5), 620 - 3
Pathway engineering for the production of aromatic compounds in Escherichia coli; Flores N et al.; Glucose is the preferred substrate for certain fermentation processes . During its internalization and concomitant formation of glucose-6-phosphate through the glucose phosphotransferase system (PTS), one molecule of phosphoenolpyruvate (PEP) is consumed . Together with erythrose 4-phosphate (E4P), PEP is condensed to form 3-deoxy-D-arabino-heptulosonate 7-phosphate (DAHP), the first intermediate of the common segment of the aromatic pathway . From this metabolic route, several commercially important aromatic compounds can be obtained . We have selected Escherichia coli mutants that can transport glucose efficiently by a non-PTS uptake system . In theory, this process should increase the availability of PEP for other biosynthetic reactions . Using these mutants, in a background where the DAHP synthase (the enzyme that catalyzes the condensation of PEP and E4P into DAHP) was amplified, we were able to show that at least some of the PEP saved during glucose transport, can be redirected into the aromatic pathway . This increased carbon commitment to the aromatic pathway was enhanced still further upon amplification of the E . coli tktA gene that encodes for a transketolase involved in the biosynthesis of E4P.

J Antibiot (Tokyo), 1998 Apr, 51(4), 394 - 401
Signal transduction inhibitors, hibarimicins, A, B, C, D and G produced by Microbispora . I . Taxonomy, fermentation, isolation and physico-chemical and biological properties; Kajiura T et al.; Strain TP-AO121 which produces a complex of novel tyrosine kinase inhibitors designated hibarimicins A, B, C, D and G was considered to be a new subspecies of Microbispora rosea, and the name, Microbispora rosea subsp . hibaria, was proposed . Hibarimicins A, B, C and D specifically inhibited the src tyrosine kinase activity without affecting protein kinase A or protein kinase C . They also showed in vitro anti-Gram-positive bacterial and antitumor activities . The molecular formulae of hibarimicins A, B, C, D and G were assigned to be C85H112O37, C85H112O37, C83H110O36, C85H112O38, and C85H112O39 respectively.

Eur J Clin Nutr, 1998 May, 52(5), 368 - 71
Delayed gastric emptying rate may explain improved glycaemia in healthy subjects to a starchy meal with added vinegar; Liljeberg H et al.; OBJECTIVES: The aim of the study was to evaluate the possible influence of acetic acid (administered as vinegar) on the postprandial glucose and insulin responses, and the potential involvement of a modified gastric emptying rate was studied by use of paracetamol as a marker . DESIGN: The white bread reference meal as well as the corresponding meal supplemented with vinegar had the same content of starch, protein and fat . The meals were served in the morning after an over-night fast and in random order . Capillary blood samples for analysis of glucose, insulin and paracetamol were collected postprandially . SETTING: The study was performed at the Department of Applied Nutrition and Food Chemistry, Lund University, Sweden . SUBJECTS: Ten healthy volunteers, seven women and three men, aged 22-51 y, with normal body mass indices were recruited . RESULTS: The presence of acetic acid, given as vinegar, significantly reduced the postprandial glucose (GI=64) and insulin responses (II=65) to a starchy meal . As judged from lowered paracetamol levels after the test meal with vinegar, the mechanism is probably a delayed gastric emptying rate . CONCLUSIONS: Fermented foods or food products with added organic acids should preferably be included in the diet in order to reduce glycaemia and insulin demand.

Plant Foods Hum Nutr, 1997, 51(3), 265 - 75
Chemical and sensory evaluation of vegetable milks from African yam bean Sphenostylis stenocarpa (Hochst ex A Rich) Harms and maize (Zea mays L.); Nnam NM; Vegetable milks were developed from fermented and unfermented African yam bean (AYB) flours and their maize blends . AYB was cleaned, dehulled, milled and fermented for 24 hours by the natural microflora present in the legume flour . Maize was fermented for 48 hours . A ratio of 70:30 (protein basis) of AYB: maize was used to formulate the blends . Vegetable milks were prepared from the AYB flours and their maize blends . Standard assay techniques were used to evaluate the milks for proximate, mineral, ascorbate and antinutrient composition . The protein contents of the milks (1.47-2.06 percent) was comparable to soymilk (2.04 percent) and bambara groundnut milk (2.00 percent) . The milks contained appreciable quantities of carbohydrate and minerals tested . The milk blends had traces of ascorbate and contained higher phosphorus than the milks from the AYB flours . The fermented milk blend had higher protein, ash and sugar levels and lower phytate and stachyose levels compared to non-fermented blend . Raffinose was reduced to trace levels in the fermented milks . The milks were appetizing . The fermented milk blend was more acceptable than others and was preferred in terms of flavor and color . It had greater advantages over the other vegetable milks evaluated in terms of zinc, phosphorus and stachyose levels.

J Dairy Res, 1998 May, 65(2), 253 - 60
Influence of thermal and other manufacturing stresses on retinol isomerization in milk and dairy products; Panfili G et al.; An analytical procedure, based upon HPLC, has been used to determine the degree of isomerization of retinol (vitamin A) in various dairy products . In raw milks, which are not subjected to thermal processing, there was no conversion of the predominant all-trans-isomers to cis-isomers in samples from various species . Pasteurized milks with mild heat treatment (high quality milk) had an average 13-cis: all-trans ratio of 2.6%, while pasteurized milk treated for 15 s at temperatures ranging from 72 to 76 degrees C had an average ratio of 6.4% . Milk subjected to more severe heat treatments had a higher degree of isomerization (UHT milk, 15.7%; sterilized milk, 33.5%), consistent with increased thermal conversion of the retinol isomers . In pasteurized and UHT cream, the increase in 13-cis-isomer was also a consequence of heat treatment (pasteurized cream, 3.0%; UHT cream, 14.4%) . The presence of cis isomers in fermented milk suggests that fermentation processes, directly or indirectly, can induce cis-trans isomerization . In the cheeses analysed, the extent of retinol isomerization ranged from 7.6 to 35.0% . Our results confirm the importance of individual isomers in evaluating the vitamin A status of dairy products.

Appl Biochem Biotechnol, 1998 Spring, 70-72, 939 - 53
Efficient production of mannan-degrading enzymes by the basidiomycete Sclerotium rolfsii; Sachslehner A et al.; Sclerotium rolfsii CBS 191.62 was cultivated on a number of carbon (C) sources, including mono- and disaccharides, as well as on polysaccharides, to study the formation of different mannan-degrading enzyme activities . Highest levels of mannanase activity were obtained when alpha-cellulose-based media were used for growth, but formation of mannanase could not be enhanced by employing galactomannan as the only carbon source . Although both xylanase and cellulase formation was almost completely repressed when S . rolfsii was grown on more readily metabolizable carbohydrates, including glucose or mannose, considerable amounts of mannanase activity were secreted under these growth conditions . Enhanced mannanase production only commenced when glucose was depleted in the medium . The maximal mannanase activity of 240 IU/mL obtained in a laboratory fermentation is remarkable . Mannanase activity formed under these derepressed conditions could be mainly attributed to one major, acidic mannanase isoenzyme with a pI value of 2.75.

Appl Biochem Biotechnol, 1998 Spring, 70-72, 919 - 28
Bioconversion of fumaric acid to succinic acid by recombinant E . coli; Wang X et al.; Succinic acid was produced efficiently from fumaric acid by a recombinant E . coli strain DH5 alpha/pGC1002 containing multicopy fumarate reductase genes . The effects of initial fumaric acid and glucose concentration on the production of succinic acid were investigated . Succinic acid reached 41 to over 60 g/L in 48.5 h starting with 50 to 64 g/L fumaric acid . Significant substrate inhibition was observed at initial fumaric acid concentration of 90 g/L . L-Malic acid became the major fermentation product under these conditions . Provision of glucose (5-30 g/L) to the fermentation medium stimulated the initial succinic acid production rate over two folds.

Appl Biochem Biotechnol, 1998 Spring, 70-72, 869 - 75
Biotechnological production of xylitol from agroindustrial residues . Evaluation of bioprocesses; Rodrigues DC et al.; Batch, fed-batch, and semicontinuous fermentation processes were used for the production of xylitol from sugarcane bagasse hemicellulosic hydrolysate . The best results were achieved by the semicontinuous fermentation process: a xylitol yield of 0.79 g/g with an efficiency of 86% and a volumetric productivity of 0.66 g/L/h.

Appl Biochem Biotechnol, 1998 Spring, 70-72, 789 - 804
beta-Cyclodextrin production by simultaneous fermentation and cyclization; Lima HO et al.; Production of beta-cyclodextrin (CD) with high-dextrose equivalent (DE) starch hydrolysates by simultaneous fermentation and cyclization (SFC) gives higher yields than using only the enzyme CGTase, because fermentation eliminates glucose and maltose that inhibit CD production, while at the same time, produces ethanol that increases yield . A 10% (w/v) solution of cassava starch, liquefied with alpha-amylase, was incubated with CGTase using: only the enzyme, added ethanol (from 1 to 5%), and added yeast S . cerevisiae (12% w/v), plus nutrients, the latter being the SFC process . Reaction conditions were: 38 degrees C, pH 6.0, DE from 2 to 25, and 3.3 mL of CGTase/L . The yield of beta-CD has decreased with an increase in DE, and maximum reaction yields were found for DE equal to 3.54, reaching 5.6, 14.7, and 11.5 mM beta-CD, respectively . For an increase of DE, of approx 6 times (from 3.54 to 23.79), beta-CD yield decreased 6 times for the first, and second reaction media with 3% (v/v) ethanol, and only approx 3 times for SFC (from 11.5 to 3.73 mM), showing that this process is less sensitive to variations in the DE.

Appl Biochem Biotechnol, 1998 Spring, 70-72, 479 - 92
Nonisothermal simultaneous saccharification and fermentation for direct conversion of lignocellulosic biomass to ethanol; Wu A et al.; The enzymatic reaction in the simultaneous saccharification and fermentation (SSF) is operated at a temperature much lower than its optimum level . This forces the enzyme activity to be far below its potential, consequently raising the enzyme requirement . To alleviate this problem, a nonisothermal simultaneous saccharification and fermentation process (NSSF) was investigated . The NSSF is devised so that saccharification and fermentation occur simultaneously, yet in two separate reactors that are maintained at different temperatures . Lignocellulosic biomass is retained inside a column reactor and hydrolyzed at the optimum temperature for the enzymatic reaction (50 degrees C) . The effluent from the column reactor is recirculated through a fermenter, which runs at its optimum temperature (20-30 degrees C) . The cellulase enzyme activity is increased by a factor of 2-3 when the hydrolysis temperature is raised from 30 to 50 degrees C . The NSSF process has improved the enzymatic reaction in the SSF to the extent that it reduces the overall enzyme requirement by 30-40% . The effect of temperature on beta-glucosidase activity was the most significant among the individual cellulase compounds . Both ethanol yield and productivity in the NSSF are substantially higher than those in the SSF at the enzyme loading of 5 IFPU/g glucan . With 10 IFPU/g glucan, improvement in productivity was more discernible for the NSSF . The terminal yield attainable in 4 d with the SSF was reachable in 40 h with the NSSF.

Appl Biochem Biotechnol, 1998 Spring, 70-72, 441 - 62
Ethanol production from AFEX-treated forages and agricultural residues; Belkacemi K et al.; Lignocellulosic materials derived from forages, namely timothy grass, alfalfa, reed canary grass, and agricultural residues, such as corn stalks and barley straw, were pretreated using ammonia fiber explosion (AFEX) process . The pretreated materials were directly saccharified by cellulolytic enzymes . Sixty to 80% of theoretical yield of sugars were obtained from the pretreated biomasses . Subsequent ethanolic fermentation of the hydrolysates by Pachysolen tannophilus ATCC 32691 resulted in 40-60% of theoretical yield after 24 h, based on the sugars present in the hydrolysates . The uptake of sugars was not complete, indicating a possible inhibitory effect on P . tannophilus during the fermentation of these substrates.

Appl Biochem Biotechnol, 1998 Spring, 70-72, 331 - 9
Factors that affect the biosynthesis of xylitol by xylose-fermenting yeasts . A review; Silva SS et al.; Xylitol is a sweetener with important technological properties like anticariogenicity, low caloric value, and negative dissolution heat . Because it can be used successfully in food formulations and pharmaceutical industries, its production is in great demand . Xylitol can be obtained by microbiological process, since many yeasts and filamentous fungi synthesize the xylose reductase enzyme, which catalyses the xylose reduction into xylitol as the first step in the xylose metabolism . The xylitol production by biotechnological means has several economic advantages in comparison with the conventional process based on the chemical reduction of xylose . The efficiency and the productivity of this fermentation chiefly depends upon the microorganism and the process conditions employed . In this mini-review, the most significant upstream parameters on xylitol production by biotechnological process are described.

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