Z Lebensm Unters Forsch, 1992 Sep, 195(3), 235 - 8 {Occurrence of beta-phenylethylamine and its derivatives in cocoa and cocoa products}; Ziegleder G et al.; 2-Phenylethylamine was extracted from cocoa nibs and chocolates and analysed by coupled gas chromatography-mass spectroscopy . The amine concentration increases in fermentation of cocoa and decreased during roasting and alkalization . Its concentration in chocolates is dependent on non-fat cocoa contents . Previously unreported aldimines were found in cocoa powders, which arise from the condensation of phenylethylamine and aldehydes . The main component of these products is N-phenylmethyl-N-phenylmethylene amine (CAS 3240-95-7). J Clin Microbiol, 1992 Sep, 30(9), 2435 - 40 Evidence that Lo's mycoplasma (Mycoplasma fermentans incognitus) is not a unique strain among Mycoplasma fermentans strains; Sasaki T et al.; Mycoplasma fermentans incognitus has attracted much interest either as a cofactor for the progression of AIDS or as a pathogenic agent in non-AIDS-related diseases (S.-C . Lo, M . S . Dawson, P . B . Newton III, M . A . Sonoda, J . W.-K . Shih, W . F . Engler, R . Y.-H . Wang, and D . J . Wear, Am . J . Trop . Med . Hyg . 41:364-376, 1989; S.-C . Lo, M . S . Dawson, M . Wong, P . B . Newton III, M . A . Sonoda, W . F . Engler, R.Y.-H Wang, J . W.-K . Shih, H . J . Alter, and D . J . Wear, Am . J . Trop . Med . Hyg . 41:601-616, 1989; S.-C . Lo, J.W.-K . Shih, N.-Y . Yang, C.-Y . Ou, and R . Y.-H . Wang, Am . J . Trop . Med . Hyg . 40:213-226, 1989) . In the present study, the genetic and serologic properties of the incognitus strain and other M . fermentans strains were compared . Furthermore, the replication of human immunodeficiency virus type 1 (HIV-1), determined by reverse transcriptase activity and HIV-1 p24 antigen level, in peripheral blood mononuclear cells was evaluated after stimulation with mycoplasma cell lysates . The psb-2.2 viruslike infectious agent DNA probe, used to identify the incognitus strain in the tissues of AIDS and non-AIDS patients by Lo et al . (Am . J . Trop . Med . Hyg . 41:364-376 and 40:213-226, 1989), showed reaction patterns similar to those of two M . fermentans strains isolated from cell cultures but not to that of the type strain PG18 . Restriction enzyme patterns of the incognitus strain with EcoRI and HindIII were also similar to those of M . fermentans strains isolated from cell cultures . There were no remarkable differences in the immunoblot profiles between the incognitus strain and the other M . fermentans strains . These results suggest that the incognitus strain is not a unique strain among M . fermentans strains . Further, cell lysates of each M . fermentans strain could also enhance the replication of HIV-1 to a level similar to that of the incognitus strain as determined by the reverse transcriptase activity and the amount of the p24 antigen. Appl Microbiol Biotechnol, 1992 Sep, 37(6), 756 - 61 Object-oriented fuzzy expert system for on-line diagnosing and control of bioprocesses; Siimes T et al.; An object-oriented fuzzy expert system to support on-line control of an automated fermentation plant is described . The major elements of the system consist of a fuzzy inference engine, a database, a knowledge base, and an expression evaluater . The expression evaluater calculates specific rates for growth, and substrate and product formation at different physiological states during the cultivation from the measured data . The specific rates are then compared with the standard target rates stored in the database . If differences outside the set tolerances were observed, the inference engine analyses the reasons for the faults on the basis of the knowledge represented in the form of a knowledge network and fuzzy membership functions of the process variables . The fuzzy expert system was developed on the basis of a shell constructed by using the object oriented Smalltalk/V Mac programming environment, with Lac-tobacillus casei lactic acid fermentation as the example of process application. Comp Biochem Physiol Comp Physiol, 1992 Sep, 103(1), 189 - 97 An in vitro study of short-chain fatty acid concentrations, production and absorption in pig (Sus scrofa) colon; Holtug K et al.; 1 . Short-chain fatty acid concentration was 180 mmol/l in the proximal colon and decreased to 108 mmol/l in the rectum . 2 . Fermentation in chymus from different regions of the colon, showed the pattern of end products to reflect the substrate and not the site of the colon . 3 . Isolated mucosa from proximal and distal colon had electroneutral sodium absorption of 4.8 +/- 0.2 and 2.9 +/- 0.8 mueq/cm2 hr in bicarbonate free media, which was abolished in the absence of chloride . 4 . Electroneutral sodium absorption was enhanced by short-chain fatty acids in the proximal colon and could be described by Michaelis-Menten kinetics with Km 2.0-11 mmol/l and Jm 1.6-3.6 mueq/cm2 hr . In the distal colon the stimulation was smaller and propionate even inhibited sodium absorption . 5 . Butyrate was absorbed in the proximal colon, whereas acetate and propionate, and butyrate in the distal colon had a flux ratio of one . 6 . Amiloride (5 mmol/l) inhibited sodium absorption and net butyrate absorption. Arch Latinoam Nutr, 1992 Sep, 42(3), 301 - 8 Biological utilization of naturally fermented pearl millet flour (Pennisetum typhoideum); Khetarpaul N et al.; Natural fermentation of pearl millet flour at 20, 25 and 30 degrees for 72 h brought about an improvement in its apparent and true protein digestibility . Utilisable protein, net protein retention and protein retention efficiency values were also enhanced as a result of fermentation . Rats fed on flour fermented at 20 and 25 degrees C had higher food as well as protein efficiency ratios than the flour fermented at 30 degrees C . Feeding of the fermented products did not bring about any histopathological abnormality in rats . Cutlets prepared from the fermented flour were organoleptically acceptable to a panel of judges. J Dairy Sci, 1992 Sep, 75(9), 2394 - 408 Influence of dietary fiber and buffer value index on the ruminal milieu of lactating dairy cows; Le Ruyet P et al.; The influence of dietary buffer value index and dietary ADF content on ruminal fluid pH, buffering capacity, and buffer value index was measured . Four lactating Holstein cows (two primiparous) averaging 72 +/- 60 DIM were used in a 4 x 4 Latin square with 3-wk experimental periods . Treatments were a 2 x 2 factorial arrangement of TMR containing two ADF concentrations (16 and 21% of DM) and two buffer value indexes (calculated from analysis of individual dietary ingredients to be -200 and 0) . Milk fat content and milk fat yield tended to be increased by high ADF, and protein yield tended to increase with low buffer value index and low ADF . Although the high ADF diets increased ruminal fluid pH, they reduced buffering capacity; because the magnitude of the pH increase was greater than the reduction in buffering capacity, ruminal fluid buffer value index was increased by added ADF . The high buffer value index diets reduced ruminal fluid pH and increased ruminal fluid buffering capacity; effects on pH outweighed those on buffering capacity so that the ruminal fluid index paradoxically decreased as the dietary index increased . Ruminal fluid acetate increased and propionate decreased as ADF increased . We conclude that ruminal fluid buffer value index increases with dietary ADF, likely because of reduced ruminal concentrations of fermentation acids . Because diets with the highest index produced the lowest ruminal indexes, dietary buffer value index must be studied further before it can be included in any model purporting to predict the need for supplemental dietary buffers. J Antibiot (Tokyo), 1992 Sep, 45(9), 1397 - 403 A novel inositol mono-phosphatase inhibitor from Memnoniella echinata . Producing organism, fermentation, isolation, physicochemical and in vitro biological properties; Lam YK et al.; A novel inositol mono-phosphatase inhibitor, L-671,776 (1), was discovered from a culture of the hyphomycete, Memnoniella echinata (ATCC 20928) . 1 has a molecular weight of 388 and a molecular formula of C23H32O5 . The mode of inhibition is non-competitive, with a Ki of 450 microM . It shows no inhibition of myo-inositol 1,4-bisphosphate 1-phosphatase or myo-inositol 1,4,5-triphosphate 5-phosphatase, although it weakly inhibits myo-inositol 1,4,5-triphosphate 3-kinase (IC50 = 3 mM) . It elevates inositol monophosphates in rat parotid slices (EC50 approximately 3 mM), but abolishes agonist effects . It also produces short-lived contraction of guinea pig trachea at 300 microM. Mol Cell Biol, 1992 Sep, 12(9), 4197 - 208 ABF1 is a phosphoprotein and plays a role in carbon source control of COX6 transcription in Saccharomyces cerevisiae; Silve S et al.; Previously, we have shown that the Saccharomyces cerevisiae DNA-binding protein ABF1 exists in at least two different electrophoretic forms (K . S . Sweder, P . R . Rhode, and J . L . Campbell, J . Biol . Chem . 263: 17270-17277, 1988) . In this report, we show that these forms represent different states of phosphorylation of ABF1 and that at least four different phosphorylation states can be resolved electrophoretically . The ratios of these states to one another differ according to growth conditions and carbon source . Phosphorylation of ABF1 is therefore a regulated process . In nitrogen-starved cells or in cells grown on nonfermentable carbon sources (e.g., lactate), phosphorylated forms predominate, while in cells grown on fermentable carbon sources (e.g., glucose), dephosphorylated forms are enriched . The phosphorylation pattern is affected by mutations in the SNF1-SSN6 pathway, which is involved in glucose repression-depression . Whereas a functional SNF1 gene, which encodes a protein kinase, is not required for the phosphorylation of ABF1, a functional SSN6 gene is required for itsd ephosphorylation . The phosphorylation patterns that we have observed correlate with the regulation of a specific target gene, COX6, which encodes subunit VI of cytochrome c oxidase . Transcription of COX6 is repressed by growth in medium containing a fermentable carbon source and is derepressed by growth in medium containing a nonfermentable carbon source . COX6 repression-derepression is under the control of the SNF1-SSN6 pathway . This carbon source regulation is exerted through domain 1, a region of the upstream activation sequence UAS6 that binds ABF1 (J . D . Trawick, N . Kraut, F . Simon, and R . O . Poyton, Mol . Cell Biol . 12:2302-2314, 1992) . We show that the greater the phosphorylation of ABF1, the greater the transcription of COX6 . Furthermore, the ABF1-containing protein-DNA complexes formed at domain 1 differ according to the phosphorylation state of ABF1 and the carbon source on which the cells were grown . From these findings, we propose that the phosphorylation of ABF1 is involved in glucose repression-derepression of COX6 transcription. Appl Biochem Biotechnol, 1992 Sep, 36(3), 227 - 34 Ethanol production from cellulose by coupled saccharification/fermentation using Saccharomyces cerevisiae and cellulase complex from Sclerotium rolfsii UV-8 mutant; Deshpande MV; Using cellulase/hemicellulase complex of Sclerotium rolfsii UV-8 mutant and Saccharomyces cerevisiae for fermentation, the coupled saccharification/fermentation (CSF) of 15% AT-rice straw was carried out at 40 degrees C, pH 4.5 for the first 24 h and further incubation was performed at 30 degrees C for 72 h . Increasing the amount of cellulase activity from 3-12 IU FPA/g of substrate resulted in increased yields of ethanol from 1.5-3.6% in 96 h . It has been observed that the coupled system was advantageous over the two stage (separate hydrolysis/fermentation) system as it produced higher amounts of ethanol from cellulose (3.6% as compared to 2.3% ethanol from rice straw). Arch Biochem Biophys, 1992 Aug 1, 296(2), 474 - 81 Stimulation by heme of steryl ester synthase and aerobic sterol exclusion in the yeast Saccharomyces cerevisiae; Keesler GA et al.; Saccharomyces cerevisiae sterol and heme auxotrophs were used to elucidate a role for hemes in sterol esterification . Steryl ester synthase (SES) activity was stimulated on average fourfold in cells supplemented with 50 micrograms/ml delta-aminolevulinic acid (ALA) . This stimulation was not dependent on ALA per se, but on the ability of this precursor to effect heme competency . The addition of ALA stimulated SES activity of yeast on either fermentative or respiratory carbon sources . The elevation of SES activity was independent of intracellular free sterol, unsaturated fatty acid, or methionine levels . SES activity increases as the cells enter stationary phase, and this increase is enhanced by heme competency . SES was directly inhibited by the hypocholesterolemic drug lovastatin (mevinolin) . The inhibition of SES activity by lovastatin was enhanced in heme-competent cells. J Gen Microbiol, 1992 Aug, 138 ( Pt 8), 1657 - 64 Production of cellulolytic and xylanolytic enzymes during growth of the anaerobic fungus Piromyces sp . on different substrates; Teunissen MJ et al.; Piromyces sp . strain E2, an anaerobic fungus isolated from an Indian elephant (hindgut fermenter) was tested for its ability to ferment a range of substrates . The fungus was able to use bagasse, cellobiose, cellulose, fructose, glucose, lactose, mannose, starch, wheat bran, wheat straw, xylan and xylose . Formate and acetate were the main fermentation products after growth on these substrates . The amount of carbon found in the fermentation products of cultures, in which substrate digestion was complete averaged 88.5 mM, or 59% of the carbon offered as substrate . No growth was observed on other substrates tested . Lactose, starch, cellobiose and filter paper cellulose were good inducers of cellulolytic and xylanolytic enzymes . Cellulolytic and xylanolytic enzymes were produced constitutively by Piromyces strain E2, although enzyme activities were generally lower after growth on glucose and other soluble sugars . Complex substrates (bagasse, wheat bran, and wheat straw) were good inducers for xylanolytic enzymes but not for cellulolytic enzymes . The extracellular protein banding pattern after SDS-PAGE was therefore only slightly affected by the growth substrate . Identical beta-glucosidase and endoglucanase activity patterns were found after growth on different substrates . This indicated that differences in enzyme activities were not the result of secretion of different sets of isoenzymes although it remains possible that the relative amount of each isoenzyme produced is influenced by the growth substrate. Appl Environ Microbiol, 1992 Aug, 58(8), 2667 - 9 Metabolism of 3-methylindole by a methanogenic consortium; Gu JD et al.; A methanogenic 3-methylindole (3-MI)-degrading consortium, enriched from wetland soil, completely mineralized 3-MI . Degradation proceeded through an initial hydroxylation reaction forming 3-methyloxindole . The consortium was unable to degrade oxindole or isatin, suggesting a new pathway for 3-MI fermentation. Appl Environ Microbiol, 1992 Aug, 58(8), 2583 - 91 Response surface analysis of the effects of pH and dilution rate on Ruminococcus flavefaciens FD-1 in cellulose-fed continuous culture; Shi Y et al.; The ruminal cellulolytic bacterium Ruminococcus flavefaciens FD-1 was grown in cellulose-fed continuous culture with 20 different combinations of pH and dilution rate (D); the combinations were selected according to the physiological pH range of the organism (6.0 to 7.1) and growth rate of the organism on cellulose (0.017 to 0.10 h-1) . A response surface analysis was used to characterize the effects of pH and D on the extent of cellulose consumption, growth yield, soluble sugar concentration, and yields of fermentation products . The response surfaces indicate that pH and D coordinately affect cellulose digestion and growth yield in this organism . As expected, the net cellulose consumption increased with increasing D while the fraction of added cellulose that was utilized decreased with increasing D . The effect of changes in pH within the physiological range on cellulose consumption was smaller than that of changes in D . Cellulose degradation was less sensitive to low pH than to high pH . At low Ds (longer retention times), cellulose degradation did not follow first-order kinetics . This decreased rate of cellulose digestion was not due to poor mixing, limitation by other medium components, or preferential utilization of the more amorphous fraction of the cellulose . The cell yield increased from 0.13 to 0.18 mg of cells per mg of cellulose with increasing Ds from 0.02 to 0.06 h-1 and decreased when the pH was shifted from the optimum of 6.5 to 6.8 . The effect of pH on cell yield increased with increasing D . The reduced cell yield at low pH appears to be due to both an increase in maintenance energy requirements and a decrease in true growth yield. Appl Environ Microbiol, 1992 Aug, 58(8), 2565 - 70 Contribution of anaerobic protozoa and methanogens to hindgut metabolic activities of the American cockroach, Periplaneta americana; Gijzen HJ et al.; The ciliate Nyctotherus ovalis occurs in high numbers in the hindgut of the American cockroach (Periplaneta americana) and harbors methanogenic bacteria as endosymbionts . The contribution of these hindgut microorganisms to metabolic and developmental processes of P . americana was studied by comparing cultures of cockroaches in which the composition of the hindgut microbial population was altered in various ways . Rearing the insects protozoan free resulted in increased insect generation time, decreased adult body weight, and absence of methane production . After feeding of protozoan-free adult cockroaches with a hindgut suspension containing N . ovalis and methanogens, methane increased to normal values and insect body weight was restored during the development of the second generation of insects . Feeding the protozoan-free cockroaches a hindgut suspension which was made free of N . ovalis resulted in an increase in methane production to only about 20% of the normal methane production level . This suggests that the methanogenic endosymbionts of N . ovalis are the major source of methane production in the hindgut . Inhibition of methanogens by addition of bromoethanesulfonic acid to the drinking water of a normal cockroach culture resulted in a reduction of methane production to about 2% of the normal level . No effects on insect body weight or the number of N . ovalis organisms were observed, but the fermentation pattern in the hindgut was shifted towards a relative increase in propionate levels . Similar results were obtained for in vitro cultures of hindgut microorganisms treated with bromoethanesulfonic acid . The results suggest a major role for hindgut protozoa in cockroach metabolic activities, especially during the insect growth period . The relatively large amounts of methane produced by cockroaches and by other methane-producing xylophagous insects suggest a major contribution by insects to global methane production. Appl Environ Microbiol, 1992 Aug, 58(8), 2513 - 6 Fate of Escherichia coli O157:H7 as affected by pH or sodium chloride and in fermented, dry sausage; Glass KA et al.; The influence of pH adjusted with lactic acid or HCl or sodium chloride concentration on survival or growth of Escherichia coli O157:H7 in Trypticase soy broth (TSB) was determined . Studies also determined the fate of E . coli O157:H7 during the production and storage of fermented, dry sausage . The organism grew in TSB containing less than or equal to 6.5% NaCl or at a pH of 4.5 to 9.0, adjusted with HCl . When TSB was acidified with lactic acid, the organism grew at pH 4.6 but not at pH 4.5 . A commercial sausage batter inoculated with 4.8 x 10(4) E . coli O157:H7 per g was fermented to pH 4.8 and dried until the moisture/protein ratio was less than or equal to 1.9:1 . The sausage chubs were then vacuum packaged and stored at 4 degrees C for 2 months . The organism survived but did not grow during fermentation, drying, or subsequent storage at 4 degrees C and decreased by about 2 log10 CFU/g by the end of storage . These studies reveal the importance of using beef containing low populations or no E . coli O157:H7 in sausage batter, because when initially present at 10(4) CFU/g, this organism can survive fermentation, drying, and storage of fermented sausage regardless of whether an added starter culture was used. Appl Environ Microbiol, 1992 Aug, 58(8), 2410 - 4 Moderation of ruminal fermentation by ciliated protozoa in cattle fed a high-grain diet; Nagaraja TG et al.; The objective of this study was to assess the influence of ciliated protozoa on ruminal fermentation in cattle fed high-grain diets . Six ruminally cannulated steers fed a corn-based grain diet (85% concentrate plus 15% alfalfa hay) at 12-h intervals were assigned randomly to two groups, ciliate free and faunated, in a crossover design . Defaunation was by ruminal emptying, omasal flushing, and treatment with sodium sulfosuccinate . Two to 3 weeks after defaunation, the ruminal contents of all steers were sampled before the morning feeding (0 h) and at 1, 2, 4, 6, 8, and 12 h after feeding to measure pH, analyze fermentation products, and monitor counts of ciliated protozoa and lactic acid-producing and -fermenting bacterial groups . Total numbers of ciliated protozoa in the faunated steers averaged 4.3 x 10(5)/g, and the protozoa consisted of nine genera . Ciliate-free steers had lower (P less than 0.01) ruminal pHs (pH 5.97) than faunated cattle (pH 6.45); however, the treatment-time interaction was not significant . Ruminal lactate and ammonia concentrations were similar in both groups . The total volatile fatty acid concentration was higher (P less than 0.05) in the ciliate-free steers than in the faunated steers and exhibited a treatment-time interaction (P less than 0.05) . The acetate-to-propionate ratio was higher (P less than 0.05) in the faunated group than in the ciliate-free group and showed a treatment-time interaction (P less than 0.05) . Total anaerobic bacterial counts were about fourfold higher in the ciliate-free group than in the faunated group.(ABSTRACT TRUNCATED AT 250 WORDS) Can J Microbiol, 1992 Aug, 38(8), 753 - 7 Some nutritional requirements of a mixed culture transforming Reichstein's compound S into prednisolone; Ghanem KM et al.; Reichstein's compound S was successfully converted to prednisolone in a single-step fermentation using a mixed culture of Curvularia lunata and Mycobacterium smegmatis . Introducing additional medium at the time of bacterial inoculation and increasing the M . smegmatis inoculum to 8% were necessary for maximal dehydrogenation of cortisol to prednisolone (86%) . However, beef extract, corn-steep solids, and malt extract were inhibitory to the dehydrogenase activity and stimulatory to hydroxylase . Of the vitamins tested, nicotinic acid and riboflavin at 0.2 and 1.13 mg/L, respectively, resulted in maximum transformation of Reichstein's compound S (100%) and optimized prednisolone yields (92%) in the mixed culture . The trace elements present in the medium were sufficient for maximal transformation, and there was no need for an exogenous supply . Addition of ATP, sodium acetate, and NAD inhibited the dehydrogenation reaction. Antonie Van Leeuwenhoek, 1992 Aug, 62(1-2), 63 - 78 Peroxisome biogenesis in Saccharomyces cerevisiae; Kunau WH et al.; The observation that peroxisomes of Saccharomyces cerevisiae can be induced by oleic acid has opened the possibility to investigate the biogenesis of these organelles in a biochemically and genetically well characterized organism . Only few enzymes have been identified as peroxisomal proteins in Saccharomyces cerevisiae so far; the three enzymes involved in beta-oxidation of fatty acids, enzymes of the glyoxylate cycle, catalase A and the PAS3 gene product have been unequivocally assigned to the peroxisomal compartment . However, more proteins are expected to be constituents of the peroxisomes in Saccharomyces cerevisiae . Mutagenesis of Saccharomyces cerevisiae cells gave rise to mutants unable to use oleic acid as sole carbon source . These mutants could be divided in two groups: those with defects in structural genes of beta-oxidation enzymes (fox-mutants) and those with defects in peroxisomal assembly (pas-mutants) . All fox-mutants possess morphologically normal peroxisomes and can be assigned to one of three complementation groups (FOX1, 2, 3) . All three FOX genes have been cloned and characterized . The pas-mutants isolated are distributed among 13 complementation groups and represent 3 different classes: peroxisomes are either morphologically not detectable (type I) or present but non-proliferating (type II) . Mislocalization concerns all peroxisomal proteins in cells of these two classes . The third class of mutants contains peroxisomes normal in size and number, however, distinct peroxisomal matrix proteins are mislocalized (type III) . Five additional complementation groups were found in the laboratory of H.F . Tabak . Not all PAS genes have been cloned and characterized so far, and only for few of them the function could be deduced from sequence comparisons . Proliferation of microbodies is repressed by glucose, derepressed by non-fermentable carbon sources and fully induced by oleic acid . The regulation of four genes encoding peroxisomal proteins (PAS1, CTA1, FOX2, FOX3) occurs on the transcriptional level and reflects the morphological observations: repression by glucose and induction by oleic acid . Moreover, trans-acting factors like ADR1, SNF1 and SNF4, all involved in derepression of various cellular processes, have been demonstrated to affect transcriptional regulation of genes encoding peroxisomal proteins . The peroxisomal import machinery seems to be conserved between different organisms as indicated by import of heterologous proteins into microbodies of different host cells . In addition, many peroxisomal proteins contain C-terminal targeting signals . However, more than one import route into peroxisomes does exist.(ABSTRACT TRUNCATED AT 400 WORDS) Antonie Van Leeuwenhoek, 1992 Aug, 62(1-2), 109 - 30 The RAS-adenylate cyclase pathway and cell cycle control in Saccharomyces cerevisiae; Thevelein JM; The cell cycle of Saccharomyces cerevisiae contains a decision point in G1 called 'start', which is composed of two specific sites . Nutrient-starved cells arrest at the first site while pheromone-treated cells arrest at the second site . Functioning of the RAS-adenylate cyclase pathway is required for progression over the nutrient-starvation site while overactivation of the pathway renders the cells unable to arrest at this site . However, progression of cycling cells over the nutrient-starvation site does not appear to be triggered by the RAS-adenylate cyclase pathway in response to a specific stimulus, such as an exogenous nutrient . The essential function of the pathway appears to be limited to provision of a basal level of cAMP . cAMP-dependent protein kinase rather than cAMP might be the universal integrator of nutrient availability in yeast . On the other hand stimulation of the pathway in glucose-derepressed yeast cells by rapidly-fermented sugars, such as glucose, is well documented and might play a role in the control of the transition from gluconeogenic growth to fermentative growth . The initial trigger of this signalling pathway is proposed to reside in a 'glucose sensing complex' which has both a function in controlling the influx of glucose into the cell and in activating in addition to the RAS-adenylate cyclase pathway all other glucose-induced regulatory pathways in yeast . Two crucial problems remaining to be solved with respect to cell cycle control are the nature of the connection between the RAS-adenylate cyclase pathway and nitrogen-source induced progression over the nutrient-starvation site of 'start' and second the nature of the downstream processes linking the RAS-adenylate cyclase pathway to Cyclin/CDC28 controlled progression over the pheromone site of 'start'. Yeast, 1992 Aug, 8(8), 655 - 65 The telomere-associated MAL3 locus of Saccharomyces is a tandem array of repeated genes; Michels CA et al.; Saccharomyces strains capable of fermenting maltose contain any one of five telomere-associated MAL loci . Each MAL locus is a complex of three genes encoding the three functions required to ferment maltose: maltose permease (GENE 1), maltase (GENE 2) and the MAL trans-activator (GENE 3) . All five loci have been cloned and all are highly sequence homologous over at least a 9.0 kbp region containing these GENEs (Charron et al., Genetics 122, 307-331, 1989) . Our initial studies of strains carrying the MAL3 locus indicated the presence of linked, repeated MAL-homologous sequences (Michels and Needleman, Mol . Gen . Genet . 191, 225-230, 1983) . Here we report our analysis of the centromere-proximal MAL3-linked sequences and show that the complete MAL3 locus spans approximately 40 kbp and consists of tandemly arrayed, partial repeats of the three GENE sequences described above . In addition, the structure of the MAL3 locus is compared to that of three partially functional alleles of MAL3 . These alleles were shown to contain only MAL31 and MAL32 and their structure suggests that they resulted from MAL3 deletions removing the sequences centromere-proximal to MAL31 . The amplification and rearrangement of the telomere-linked MAL3 sequences are discussed in the context of studies on other telemere-associated sequences from yeast and other species. Scand J Gastroenterol, 1992 Aug, 27(8), 632 - 4 Absorption of wheat starch in patients resected for left-sided colonic cancer; Nordgaard I et al.; Bacterial fermentation of carbohydrate in the colon, producing short-chain fatty acids (SCFA)--and especially butyrate--has been shown possibly to impede cell proliferation and regulate cell differentiation of colonocytes . In patients with diverticular disease or benign polyps in the colon a hyperabsorption of potato starch in the small intestine has been found . We have investigated the absorption of wheat starch in 15 patients radically resected for cancer in the descending or sigmoid colon, and the results were compared with those of 15 healthy controls . The starch malabsorption was quantified by the hydrogen breath test . The patients malabsorbed 2-14 g (median, 8 g) of 100 g wheat starch ingested, and the control group malabsorbed 3-11 g (median, 6 g) (P greater than 0.1) . Mouth-to-cecum transit time for wheat starch and lactulose and the hydrogen production capacity after the lactulose standards were also similar in patients and controls . The results do not support the theory that hyperabsorption of starch is characteristic of patients with malignant disease in the large intestine. Biochem Int, 1992 Aug, 27(5), 831 - 9 D-xylose fermentation and catabolism in Fusarium oxysporum; Singh A et al.; Fusarium oxysporum exhibits different fermentative capacities when grown under different aeration conditions . Highest ethanol and acetic acid yield coefficients were obtained under semi-aerobic culture conditions . Effect of aerobiosis on the levels of key enzymes and intracellular intermediary metabolites of pentose phosphate pathway, tricarboxylic acid cycle and glycolysis exhibited striking correlation with the fermentative character of metabolism . The results are discussed in relation to the energy levels in the cell, the redox balance and mitochondrial function. J Pediatr Gastroenterol Nutr, 1992 Aug, 15(2), 146 - 9 Short-chain fatty acid absorption in patients with cystic fibrosis; Vaisman N et al.; Patients with cystic fibrosis (CF) often exhibit malabsorption despite the use of supplemental pancreatic enzymes . Unabsorbed carbohydrates and amino acids can serve as substrates for large intestine anaerobic fermentation, thus increasing excretion of short-chain fatty acids (SCFA) in the feces . Nine patients with CF on regular pancreatic enzyme supplementations in the age range of 5-11 years and one older patient were studied . Three-day stool samples were collected, as were 72-h food records . Stools were analyzed for gross energy, total nitrogen, fat content, and SCFA concentration . A significant difference was found between CF and normal controls in total caloric excretion due to fat malabsorption . No significant difference was found between CF and normal controls in protein or SCFA excretion . Fat excretion as percentage of fat intake was significantly increased in CF patients: 35.3 +/- 10.2% versus 8.0 +/- 3.0%, respectively . These data suggest that carbohydrate supplementation could be more widely used to increase caloric intake in CF patients without causing secondary osmotic diarrhea. J Dairy Sci, 1992 Aug, 75(8), 2304 - 23 Microbial protein synthesis and flows of nitrogen fractions to the duodenum of dairy cows; Clark JH et al.; Attempts have been made to increase nutrient availability for milk production by increasing feed intake, optimizing ruminal fermentation, and supplementing nutrients to the diet that will escape ruminal degradation . Energy and N are the nutritional factors that most often limit microbial growth and milk production . Ruminal fermentation and flow of microbial and dietary protein to the small intestine are affected by feed intake and by the amount and source of energy and protein in the diet . Feeding protein and carbohydrate that are not degraded in the rumen increases the quantity of dietary protein that passes to the small intestine but may decrease the quantity of microbial protein that is synthesized in the rumen . This often results in only small differences in the total NAN that passes to the small intestine . Because microbial protein supplies a large quantity of total AA that passes to the small intestine, differences in passage of individual AA often are only slight . Additional research with cows consuming large amounts of feed are needed to identify combinations of feed ingredients that synchronize availabilities of energy and N for optimizing ruminal digestion, microbial protein synthesis, nutrient flow to the small intestine, and milk production and composition. J Dairy Sci, 1992 Aug, 75(8), 2235 - 41 Effects of lasalocid on selected ruminal and blood metabolites in young calves; Quigley JD 3rd et al.; Twelve Holstein bull calves were ruminally cannulated at 5 d of age and assigned to 0 or 1 mg of lasalocid/kg of BW daily, administered postruminally via milk replacer or into the ruminal cannula . Calves were fed milk replacer for 8 wk and calf starter for 12 wk . Lasalocid administration was terminated at weaning in calves fed lasalocid in milk replacer . Ruminal pH tended to be higher in calves fed lasalocid ruminally than in calves on control treatment and averaged 5.9 and 5.6 and 5.4 and 5.1 during wk 1 to 8 and 9 to 12, respectively . Molar proportion of ruminal butyrate tended to be lower when lasalocid was added to the rumen, particularly after weaning . Blood beta-hydroxybutyrate and acetoacetate were lower when lasalocid was administered into the rumen after weaning and averaged .897 and .646 and .026 and .015 mM in calves on control and ruminal treatments, respectively . No effects of lasalocid administered via the milk replacer were observed, except for plasma NEFA, which were reduced postweaning . These data suggest that lasalocid reduces blood beta-hydroxybutyrate by changes in ruminal fermentation and subsequent metabolism of butyrate by ruminal epithelium. J Antibiot (Tokyo), 1992 Aug, 45(8), 1313 - 24 Protorubradirin, an antibiotic containing a C-nitroso-sugar fragment, is the true secondary metabolite produced by Streptomyces achromogenes var . rubradiris . Rubradirin, described earlier, is its photo-oxidation product; Bannister B et al.; In an attempt to improve the isolation of the antibiotic rubradirin from fermentations of Streptomyces achromogenes var . rubradiris, the use of preparative reversed-phase chromatography was investigated . The product isolated was a mixture of rubradirin and a new antibiotic named protorubradirin, of extremely similar structure, which is converted into rubradirin on exposure to light and air . Methanolysis of protorubradirin in the dark yields an anomeric mixture of methyl glycosides of a C-nitroso-sugar, converted photo-oxidatively into the methyl rubranitrosides derived from rubradirin . Thus, protorubradirin is the C-nitroso-analogue of rubradirin . It is suggested that the same relationship between protorubradirin and rubradirin may apply to the anthracycline antibiotics viriplanin A and viriplanin D. J Antibiot (Tokyo), 1992 Aug, 45(8), 1278 - 85 Biosynthesis of thiopeptide antibiotic A10255 in stirred reactors using a chemically defined medium supplemented with continuous nutrient feeds; Boeck LD et al.; A10255 is a complex of new thiopeptide antibiotics produced by Streptomyces gardneri . When stirred reactors were operated in batch mode using a defined medium with a glucose feed, 250 micrograms/ml of A10255 were produced during a four-day fermentation cycle . The linear growth phase of S . gardneri was extended through seven days by supplementing the defined medium with continuous feeds of hydrolyzed casein and methyl caprate . With the supplementary feeds, antibiotic biosynthesis paralleled growth during the extended cycle and attained levels of 1,750 micrograms/ml . Increasing the standard glucose feed rate increased titers principally by increasing cell mass . Supplementing the standard glucose feed with lipids such as caprylate or caprate, and decyl alcohol, affected cell mass minimally but produced higher titers by increasing the specific biosynthesis of A10255 per unit of biomass. J Antibiot (Tokyo), 1992 Aug, 45(8), 1222 - 30 A10255, a complex of novel growth-promoting thiopeptide antibiotics produced by a strain of Streptomyces gardneri . Taxonomy and fermentation studies; Boeck LD et al.; A10255 is a complex of new thiopeptide antibiotics characterized structurally by a cyclic peptide core to which is attached a side chain composed of dehydroalanine moieties . The complex contained 80-85% factor B, 15-20% factor G, and trace amounts of factors C, D, E, F, H, and J . Taxonomic studies indicated the producing microorganism to be a strain of Streptomyces gardneri . The major portion of the antibiotic produced remained associated with the mycelial biomass, from which it was extracted with polar solvents such as aqueous methanol or aqueous acetone . Initial A10255 yields of < 2 micrograms/ml were increased to over 300 micrograms/ml in stirred reactors through strain selection, nutritional studies, and conversion of the batch fermentation to a fed-batch mode. J Antibiot (Tokyo), 1992 Aug, 45(8), 1195 - 201 Folipastatin, a new depsidone compound from Aspergillus unguis as an inhibitor of phospholipase A2 . Taxonomy, fermentation, isolation, structure determination and biological properties; Hamano K et al.; A new inhibitor of phospholipase A2 was isolated from the fermentation broth of Aspergillus unguis . The structure, with a depsidone carbon skeleton, was assigned by spectroscopic experiments. Gene, 1992 Aug 1, 117(1), 53 - 60 The Mycobacterium tuberculosis 38-kDa antigen: overproduction in Escherichia coli, purification and characterization; Singh M et al.; The 38-kDa protein (Ag38) of the Gram+ bacterium, Mycobacterium tuberculosis H37Rv, is an immunodominant antigen of potential utility for diagnosis and vaccine development . Assessment of this potential requires large amounts of the purified protein that would be difficult, if not impossible, to obtain from M . tuberculosis itself . The gene coding for Ag38 had been previously cloned and in the present study was expressed as an unfused protein in Escherichia coli under the control of strong transcriptional (bacteriophage lambda pLpR) and translational (atpE) signals . Fermentation of the recombinant E . coli K-12 strain CAG629{pMS9-2}, which is deficient in Lon protease and the heat-shock response, produced recombinant Ag38 (reAg38) at high levels (about 10% of total cellular protein) . The reAg38, which accumulated as inclusion bodies, was completely solubilized in 6 M guanidine.HCl, refolded and purified to apparent homogeneity . The product showed the expected amino acid composition and M(r), and had similar reactivities as the native protein with three different mAb . Polyclonal antibodies raised against reAg38 reacted strongly with the native antigen in enzyme-linked immunosorbent assay . These results demonstrate that reAg38, which cannot be distinguished antigenically from the native protein of M . tuberculosis, can be prepared in quantity from E . coli. Appl Microbiol Biotechnol, 1992 Aug, 37(5), 615 - 20 Studies on plasmid stability, cell metabolism and superoxide dismutase production by Pgk- strains of Saccharomyces cerevisiae; Ayub MA et al.; A double mutant sod1/pgk1 strain of Saccharomyces cerevisiae has been constructed in order to investigate the effects of different environmental conditions on yeast physiology, plasmid stability, and superoxide dismutase (SOD) production . Strains were transformed with yeast episomal plasmids (YEp) containing both PGK1 and SOD1 genes and were grown on fermentable carbon sources and under vigorous aeration . Under these conditions, the presence of the PGK1 gene was made essential for growth and both genes were efficiently expressed . However, plasmid-borne PGK1 was found not to increase the stability of YEp vectors in batch cultures of Pgk- cells . Paradoxically, plasmid stability increased during the respiratory phase of growth . An investigation of the metabolism of Pgk- cells demonstrated that these glycolytic pathway mutants do not appreciably metabolize glycerol . Thus Pgk+, plasmid-containing, cells have a selective advantage during the respiratory phase of batch growth since they can utilize both glycerol and ethanol. Rev Med Chil, 1992 Aug, 120(8), 858 - 61 {Colonic fermentation in humans: effect of the ingestion of meat associated to milk}; Solomons NW et al.; The amount of breath H2 produced for 6 h following the ingestion of 240 ml of milk was used as an index of the rate of colonic fermentation of undigested lactose in 8 lactase non-persistent Guatemalan adults . Treatments in separate days included milk alone, milk with 400 g cooked beef, lactose pre-hydrolyzed milk with the same amount of beef, beef alone and fasting for 6 h . Excess excretion of H2, calculated as the mean area under the curve were 178 +/- 31 ppm h with milk alone, 50 +/- 17 with milk plus beef, -1 +/- 26 with prehydrolyzed milk (p > 0.001) . Peak increments of breath H2 followed the same trend: all 8 subjects over 20 ppm with milk alone, 2 with milk plus beef and none with hydrolyzed milk, beef alone or fasting . Thus, cooked beef significantly reduces the rate of appearance of intact lactose in the large bowel of lactase deficient adults. J Appl Bacteriol, 1992 Aug, 73(2), 163 - 7 Development changes to gut microflora metabolism in mice; Brennan-Craddock WE et al.; Developmental changes in the activities of bacterial nitrate reductase, nitroreductase and beta-glucuronidase and their response to fermentable dietary fibre, were investigated in caecal contents from suckling mice (2-week-old) and in mice aged 4-24 weeks fed either a purified fibre-free diet or that diet supplemented with 5% (w/w) pectin . There was no apparent age-related trend common to the three enzymes studied . Nitrate reductase activity in the mice fed the fibre-free diet did not markedly alter with age . Pectin administration, however, was associated with a significant increase in nitrate reductase activity, particularly in 4-week-old mice . Nitroreductase activity exhibited an overall upward trend in mice from 2 to 12 weeks and thereafter decreased . Caecal beta-glucuronidase activity in mice increased sharply between 2 weeks and 4 weeks of age, thereafter not changing significantly until the 24th week . Pectin feeding had no consistent effect on activities either of nitroreductase or beta-glucuronidase . The changes in enzyme activities with age were not related to the concentration of bacteria in the caecum, which was highest in the 2-week-old mice . We conclude that the weaning is a period in which marked changes in caecal bacterial enzyme activities can occur. Am J Clin Nutr, 1992 Aug, 56(2), 455 - 9 Oat bran increases serum acetate of hypercholesterolemic men; Bridges SR et al.; Mechanisms for the hypocholesterolemic effects of oat bran remain unclear . Soluble fibers such as oat bran are fermented in the colon to short-chain fatty acids (SCFAs), which may enter the portal vein and attenuate hepatic cholesterol synthesis . To compare effects of oat bran and wheat bran on serum SCFA concentrations, 20 hypercholesterolemic men entered a metabolic ward and received control diets for 1 wk followed by oat-bran or wheat-bran diets for 3 wk . Oat bran decreased serum cholesterol 12.8% (P less than 0.001) whereas wheat bran had no effect . Peripheral serum SCFA concentrations were measured seven times over 14 h at the end of each diet . Serum acetate values from 1200 to 2200 were significantly higher in subjects fed oat-bran vs wheat-bran diets . Peak and incremental peak acetate values were also significantly higher than control values in subjects fed oat bran but not in subjects fed wheat bran . SCFA responses may contribute to the hypocholesterolemic effects of oat bran. Biochim Biophys Acta, 1992 Jul 29, 1127(2), 191 - 8 Use of specific polyclonal antibodies to detect heterogeneous lipases from Geotrichum candidum; Charton E et al.; Geotrichum candidum CMICC 335426 was previously shown to produce two lipases termed lipase A and lipase B, lipase B being highly specific for hydrolysis of esters of cis-delta 9 fatty acids . We now describe the isolation of polyclonal antibodies specific for lipase A and lipase B . These antibodies were used in Western blotting techniques to detect the appearance of the lipases during the course of the fermentation of G . candidum CMICC 335426 . A and B were found to be produced simultaneously in the extracellular medium at the start of the growth phase . The two lipases were always present at similar levels in the medium . The specific antibodies were then used to detect the presence of A- and B-like lipases in crude lipase samples from other strains of G . candidum . The lipases were found at different levels in all these samples, and the specificities of the crude lipases varied significantly from one strain to another . Differences in specificity could therefore be explained by different levels of specific (B-type) and non-specific (A-type) lipases in the medium . This was verified by purifying A- and B-type lipases from the G . candidum strain ATCC 34614. J Biol Chem, 1992 Jul 25, 267(21), 14697 - 702 The mitochondrial F1ATPase alpha-subunit is necessary for efficient import of mitochondrial precursors; Yuan H et al.; The mitochondrial import and assembly of the F1ATPase subunits requires, respectively, the participation of the molecular chaperones hsp70SSA1 and hsp70SSC1 and other components operating on opposite sides of the mitochondrial membrane . In previous studies, both the homology and the assembly properties of the F1ATPase alpha-subunit (ATP1p) compared to the groEL homologue, hsp60, have led to the proposal that this subunit could exhibit chaperone-like activity . In this report the extent to which this subunit participates in protein transport has been determined by comparing import into mitochondria that lack the F1ATPase alpha-subunit (delta ATP1) versus mitochondria that lack the other major catalytic subunit, the F1ATPase beta-subunit (delta ATP2) . Yeast mutants lacking the alpha-subunit but not the beta-subunit grow much more slowly than expected on fermentable carbon sources and exhibit delayed kinetics of protein import for several mitochondrial precursors such as the F1 beta subunit, hsp60MIF4 and subunits 4 and 5 of the cytochrome oxidase . In vitro and in vivo the F1 beta-subunit precursor accumulates as a translocation intermediate in absence of the F1 alpha-subunit . In the absence of both the ATPase subunits yeast grows at the same rate as a strain lacking only the beta-subunit, and import of mitochondrial precursors is restored to that of wild type . These data indicate that the F1 alpha-subunit likely functions as an "assembly partner" to influence protein import rather than functioning directly as a chaperone . These data are discussed in light of the relationship between the import and assembly of proteins in mitochondria. Biochim Biophys Acta, 1992 Jul 22, 1136(1), 57 - 67 Glucose-induced activation of plasma membrane H(+)-ATPase in mutants of the yeast Saccharomyces cerevisiae affected in cAMP metabolism, cAMP-dependent protein phosphorylation and the initiation of glycolysis; dos Passos JB et al.; Addition of glucose-related fermentable sugars or protonophores to derepressed cells of the yeast Saccharomyces cerevisiae causes a 3- to 4-fold activation of the plasma membrane H(+)-ATPase within a few minutes . These conditions are known to cause rapid increases in the cAMP level . In yeast strains carrying temperature-sensitive mutations in genes required for cAMP synthesis, incubation at the restrictive temperature reduced the extent of H(+)-ATPase activation . Incubation of non-temperature-sensitive strains, however, at such temperatures also caused reduction of H(+)-ATPase activation . Yeast strains which are specifically deficient in the glucose-induced cAMP increase (and not in basal cAMP synthesis) still showed plasma membrane H(+)-ATPase activation . Yeast mutants with widely divergent activity levels of cAMP-dependent protein kinase displayed very similar levels of activation of the plasma membrane H(+)-ATPase . This was also true for a yeast mutant carrying a deletion in the CDC25 gene . These results show that the cAMP-protein kinase A signaling pathway is not required for glucose activation of the H(+)-ATPase . They also contradict the specific requirement of the CDC25 gene product . Experiments with yeast strains carrying point or deletion mutations in the genes coding for the sugar phosphorylating enzymes hexokinase PI and PII and glucokinase showed that activation of the H(+)-ATPase with glucose or fructose was completely dependent on the presence of a kinase able to phosphorylate the sugar . These and other data concerning the role of initial sugar metabolism in triggering activation are consistent with the idea that the glucose-induced activation pathways of cAMP-synthesis and H(+)-ATPase have a common initiation point. J Nutr, 1992 Jul, 122(7), 1508 - 20 Short-chain fatty acid production and fiber degradation by human colonic bacteria: effects of substrate and cell wall fractionation procedures; Bourquin LD et al.; Three dietary fiber sources (corn fiber, oat bran, wheat bran) were analyzed for chemical composition and potential fermentation by human colonic bacteria in vitro . Total dietary fiber (TDF) concentration of substrates was 64.3, 11.1 and 50.4 g/100 g dry matter for corn fiber, oat bran and wheat bran, respectively . Original material (ORIG), TDF fractions and simulated (SIM) cell wall fractions (produced by combining cellulose, hemicelluloses and pectic substances in proportions they represented in the cell wall) from each substrate were fermented in vitro for 6, 12, 18, 24 or 48 h using inoculum prepared from freshly voided feces from each of three human volunteers . Substrate dry matter remaining after 48 h of fermentation was 87.8, 39.8 and 73.5% for TDF fractions of corn fiber, oat bran and wheat bran, respectively . Disappearance of ORIG fractions was considerably greater than that of TDF due to fermentation of nonfibrous material . Disruption of cell wall structure during isolation of polysaccharide fractions allowed for dramatically increased fermentability of SIM relative to TDF . Averaged across all treatments, production of the short-chain fatty acids, acetate, propionate and butyrate, occurred in the molar ratio 63:21:16; however, profiles of short-chain fatty acids produced were influenced by both treatment and inoculum source . Extent of substrate fermentation varied among inoculum donors, implying that colonic microbial activities differ among individuals . Potential colonic fermentability of fiber sources was influenced by substrate, method of fiber preparation and inoculum source. Nucleic Acids Res, 1992 Jul 11, 20(13), 3495 - 500 A negative regulating element controlling transcription of the gene encoding acyl-CoA oxidase in Saccharomyces cerevisiae; Wang TW et al.; Peroxisomes are induced in Saccharomyces cerevisiae when this yeast is grown in the presence of oleate, and are repressed when glucose is supplied as the carbon source . Concomitant with this is an induction/repression of peroxisomal beta-oxidation enzymes . We are investigating the transcriptional control of acyl-CoA oxidase, the first and rate-limiting enzyme in the peroxisomal beta-oxidation cycle . The promoter region of POX1 from S . cerevisiae has been analyzed in POX1/lacZ fusions . Expression of the POX1/lacZ fusion protein underwent glucose repression and oleate induction . By deletion, DNA band shift and DNase I footprinting analyses we have identified a region that is involved in transcriptional repression of POX1 . Elimination of this DNA sequence results in constitutive expression of POX1 when S . cerevisiae is grown on a fermentable carbon source or glycerol. Nippon Yakurigaku Zasshi, 1992 Jul, 100(1), 67 - 76 {Effect of SL-1010 (sodium hyaluronate with high molecular weight) on experimental osteoarthritis induced by intra-articularly applied papain in rabbits}; Kitoh Y et al.; Sodium hyaluronate (HA) with a molecular weight of approximately 600,000-1,200,000 is reportedly effective against osteoarthritis (OA) . However, since HA with higher molecular weight is expected to be more effective against OA, we investigated the effects of HA (SL-1010) newly produced by fermentation with a molecular weight of 1,800,000-2,100,000 on the experimental OA induced by intraarticular injection of papain, into the knee joint of the rabbit, in comparison with those of HA with a molecular weight of about 950,000 (HA-95) . When 0.4, 0.8, and 1.6% papain (0.5ml) was injected into the knee joint of the animal twice with a 3-day interval, there were dose-dependent degenerative changes and a decrease in sulfated glycosaminoglycan (S-GAG) in the articular cartilage with slight synovial inflammatory changes 6 weeks after the final injection of papain . In this OA model, intraarticular application of SL-1010 slightly reduced the degeneration of articular cartilage, compared with the injections of HA-95 or saline (control) . SL-1010 also caused a significant recovery in the S-GAG level which was decreased in the cartilage of the OA model, compared with the control . In addition, SL-1010 inhibited the release of 35S-GAG from the cartilage obtained from normal and OA model joints . These results suggest that SL-1010 is effective in inhibiting the degeneration of cartilage in the OA model, probably due to the recovery of the S-GAG level by reducing the release of S-GAG from the cartilage. Appl Environ Microbiol, 1992 Jul, 58(7), 2331 - 3 Vitamin B12-dependent propionate production by the ruminal bacterium Prevotella ruminicola 23; Strobel HJ; When Prevotella ruminicola 23 was grown in a defined medium containing a vitamin mixture, significant amounts of propionate were formed . Succinate and acetate were the major fermentation acids produced when vitamins were omitted, and further experiments demonstrated that propionate formation was dependent on vitamin B12 . When the organism was grown in continuous culture at dilution rates of less than 0.20 h-1, propionate and acetate were the predominant fermentation products and little succinate was formed when vitamin B12 was present . However, at higher dilution rates, propionate formation declined and succinate accumulated . Since cell protein yields were reduced 15 to 25% in the absence of vitamin B12, the pathway for propionate formation may contain an energy-conserving step. Appl Environ Microbiol, 1992 Jul, 58(7), 2201 - 10 Influence of ecosystematic factors on survival of Escherichia coli after large-scale release into lake water mesocosms; Brettar I et al.; Mass cultures of an Escherichia coli K-12 strain were released into exposed mesocosms in a eutrophic lake . The release was performed with and without additional input of the E . coli culture medium to stimulate the scenario of leakage of a production fermenter on one hand and to compare the influence of the added organic nutrients with that of the added strain on the other hand . The survival of the introduced strain and the influence on ecological processes in the mesocosms were monitored for 10 weeks after release . For comparison, survival of the strain in microcosms with sterile lake water was also monitored . Survival of the strain was determined by means of immunofluorescence and growth on selective agar medium . In lake mesocosms, E . coli showed a rapid and constant dieback during the first week . After 4 days, cells were mostly restricted to particles, which seemed to provide niches for survival . From the second week onward, survival was improved in mesocosms with culture medium added . In microcosms with sterile lake water, plate counts of E . coli showed a strong decrease within 2 weeks, while total cell numbers remained approximately the same . The rapid elimination of E . coli from the free-water phase of the mesocosms was probably due to the combined effect of the inability to grow in lake water and grazing . The better survival of E . coli (mainly on particles) in mesocosms with added medium was attributed to the medium-induced enhancement of primary production, which was the source of a large quantity of particles . These particles, in turn, may have functioned as niches for prolonged survival as well as transport vehicles for sedimentation of the E . coli cells. J Clin Microbiol, 1992 Jul, 30(7), 1807 - 10 Molecular detection of sorbitol-fermenting Escherichia coli O157 in patients with hemolytic-uremic syndrome; Gunzer F et al.; Shiga-like toxin-producing Escherichia coli strains of serogroup O157 were identified in 26 of 104 patients with hemolytic-uremic syndrome and in 18 of 668 patients with diarrhea . All strains were identified by colony hybridization with DNA probes complementary to Shiga-like toxin I and Shiga-like toxin II gene sequences and characterized by biochemical tests and serotyping . Seventeen of these 44 patients had E . coli O157 strains which were unusual because they fermented sorbitol within 24 h of incubation and were positive for beta-glucuronidase activity . Culture filtrates of these sorbitol-fermenting strains were highly toxic to Vero cells in culture . Serological tests and DNA analysis performed by restriction endonuclease digestion of B-subunit toxin genes revealed that all 17 isolates produced Shiga-like toxin II . Although by using molecular probes we established a high frequency of sorbitol-fermenting E . coli O157 strains in the patients we examined, further studies on the prevalence of such isolates in other areas of endemic disease are clearly warranted. J Nutr, 1992 Jul, 122(7), 1425 - 33 A method for estimating the available energy of incompletely digested carbohydrates in rats; Juhr NC et al.; We developed a method to estimate the available energy from carbohydrates that are unavailable or partially unavailable through direct digestion and absorption . Radiolabeled bacterial and plant cellulose and polydextrose were administered orally to germfree and conventional rats . Label in breath, feces, intestinal contents and carcass were determined with excellent total recovery of the administered label . Comparison of these measurements in germfree and conventional rats was used to calculate the energy directly available by digestion and that available only after fermentation . Although the method overestimates available energy because of the more efficient digestive metabolism of the germfree rat, it provides a reliable, maximum energy value based upon fewer assumptions than previous methods . In conventional rats, 65% of the administered cellulose and 54% of the administered polydextrose were recovered in feces . In conventional rats, appreciable amounts of cellulose were fermented and an available energy value of 3.5 kJ/g was calculated . Calculation of the total availability of polydextrose, taking into account the direct absorption of small amounts of monomers present and the efficiency of fermentation, indicates an available energy value of 4.7 kJ/g. Zh Obshch Biol, 1992 Jul-Aug, 53(4), 549 - 56 {A comparative analysis of allozyme variability in vertebrate animals}; Mezhzherin SV; Comparative analysis of levels of the allozymic variation in the vertebrates is conducted using evaluation of a) within population heterozygosity of ferment coding homologous loci, b) average (per each species) allele frequencies of homologous loci, and c) overall sample of the loci being analyzed . It is established that amphibians and reptiles are characterized by the highest, birds and mammals--by the lowest, and fishes--by the middle level of genetic diversity . The diversity of genetic systems, if the constant heterozygosity of duplicated loci is taken into consideration, decreases from fishes to mammals and from cold-blooded to warm-blooded vertebrates . This tendency could be considered as an extrapolation of the "progressive specialization" rule on molecular level . Three basic factors determining certain level of genetic diversity of a species are acknowledged position in the phylogenetic system, population structure, and level of introgressive hybridization . From methodological viewpoint, evaluation of the genetic diversity by homologous loci seems to be most valid in comparative studies. FEMS Microbiol Lett, 1992 Jul 1, 73(1-2), 155 - 9 Sequential inactivation of ammonium and glucose transport in Saccharomyces cerevisiae during fermentation; Cardoso H et al.; Ethanol at concentrations above 12% (v/v) in mineral medium with glucose and with ammonium as the only nitrogen source induced rapid inactivation of the ammonium transport system in the strain IGC 3507 of Saccharomyces cerevisiae terminating protein synthesis . Subsequently, when glucose was present, the glucose transport system was irreversibly inactivated . This two-step mechanism may play a decisive role when ethanol stops fermentation by S . cerevisiae, before all the fermentable sugar has been consumed. J Antibiot (Tokyo), 1992 Jul, 45(7), 1117 - 21 TA-3037A, a new inhibitor of glutathione S-transferase, produced by actinomycetes . I . Production, isolation, physico-chemical properties and biological activities; Komagata D et al.; TA-3037A, a new inhibitor of glutathione S-transferase was discovered in the fermentation broth of Streptomyces sp . TA-3037 . It was purified by chromatography followed by solvent extraction and then isolated as yellow needles . TA-3037A has the molecular formula of C16H11NO4 . It was competitive with the substrate, and the inhibition constant (Ki) was 4.9 microM. Mol Microbiol, 1992 Jul, 6(14), 1913 - 23 Identification and characterization of narQ, a second nitrate sensor for nitrate-dependent gene regulation in Escherichia coli; Chiang RC et al.; In response to nitrate availability, Escherichia coli regulates the synthesis of a number of enzymes involved in anaerobic respiration and fermentation . When nitrate is present, nitrate reductase (narGHJI) gene expression is induced, while expression of the DMSO/TMAO reductase (dmsABC), fumarate reductase (frdABCD) and fermentation related genes are repressed . The narL and narX gene products are required for this nitrate-dependent control, and apparently function as members of a two-component regulatory system . NarX is a presumed sensor-transmitter for nitrate and possibly molybdenum detection . The presumed response-regulator, NarL, when activated by NarX then binds at the regulatory DNA sites of genes to modulate their expression . In this study a third nitrate regulatory gene, narQ, was identified that also participates in nitrate-dependent gene regulation . Strains defective in either narQ or narX alone exhibited no nitrate-dependent phenotype whereas mutants defective in both narQ and narX were fully inactive for nitrate-dependent repression or activation . In all conditions tested, this regulation required a functional narL gene product . These findings suggest that the narX and narQ products have complementary sensor-transmitter functions for nitrate detection, and can work independently to activate NarL, for eliciting nitrate-dependent regulation of anaerobic electron transport and fermentation functions . The narQ gene was cloned, sequenced, and compared with the narX gene . Both gene products are similar in size, hydrophobicity, and sequence, and contain a highly conserved histidine residue common to sensor-transmitter proteins. Plant Foods Hum Nutr, 1992 Jul, 42(3), 247 - 56 The nutritive quality of sorghum-commonbean tempe; Mugula JK; The nutritive quality of sorghum-commonbean (40:60) tempe manufactured by Rhizopus oligosporus: Rhizopus oryzae (1:1) mixed culture fermentation was determined . The protein, crude fat and ash content increased slightly, while carbohydrates decreased . The dietary fibre of the tempe increased by 10% . Mould fermentation increased the content of reducing sugars, total acid and aminonitrogen 15.3, 6.7 and 4.6-fold, respectively . It decreased the phytate content by 44% and it increased the tannic acid content by 52% . In vitro iron absorption increased from 2.8 to 12.5% . The protein efficiency ratio of tempe was 1.61 +/- 0.33; the net protein ratio was 2.39 +/- 0.20; the in vitro and in vivo protein digestibility were 88.2 and 80.0 +/- 0.05% respectively, while the protein efficiency ratio, net protein ratio in vivo digestibility of skim milk was 2.96 +/- 0.17, 3.51 +/- 0.17 and 98.0 +/- 1.87, respectively . The sorghum-bean tempe could be used for supplementary feeding. Plant Foods Hum Nutr, 1992 Jul, 42(3), 219 - 24 The effect of fermentation on the nutrient status and on some toxic components of Icacinia manni; Antai SP et al.; The effect of fermentation on the nutrient status and on some toxic components of Icacinia manni was investigated . Chemical analysis of both unfermented and fermented products revealed an increase in protein, ash and fibre content while the lipid and carbohydrate content showed a decrease . The results indicated that fermentation resulted in protein enrichment of the fermented Icacinia manni mash . Fermentation was also observed to cause a marked decrease in the level of some toxic components (oxalic acid, phytic acid and hydrocyanic acid) of the product . The possibility of incorporating Icacinia manni among the edible starchy plant tubers is discussed. J Dairy Sci, 1992 Jul, 75(7), 1923 - 35 Effects of feeding lactating dairy cows diets containing whole soybeans and tallow; Schauff DJ et al.; Four multiparous Holstein cows averaging 133 d postpartum and fitted with ruminal cannulas were utilized in a 4 x 4 Latin square design to investigate the effects of feeding diets containing whole soybeans and tallow . Treatments were 1) control, no added fat; 2) control and 10% whole raw soybeans; 3) control, 10% whole raw soybeans, and 2.5% tallow; and 4) control, 10% whole raw soybeans, and 4.0% tallow . Cows were fed for ad libitum intake a diet of alfalfa haylage, corn silage, and concentrate (45:5:50, DM basis) . Intakes of DM and production of milk, milk CP, milk SNF, and 4% FCM were not affected by feeding supplemental fat . Production of milk fat and weight percentages and yields of long-chain fatty acids in milk fat were increased, whereas weight percentages and yields of short- and medium-chain fatty acids were decreased by feeding supplemental fat . Digestibilities of DM, OM, energy, cellulose, and fatty acids were decreased slightly when fat was added to the diet, but utilization of energy and N for production of milk was not altered . Supplemental fats increased concentrations of NEFA and cholesterol in plasma . These data indicate that relatively large amounts of unprotected fat can be added to the diet of lactating dairy cows without deleterious effects on milk composition, ruminal fermentation, or nutrient digestibilities. Food Addit Contam, 1992 Jul-Aug, 9(4), 379 - 84 Changes in cassava toxicity during processing into gari and ijapu--two fermented food products; Sokari TG et al.; Grated cassava to which tap water was added at levels of 25%, 50% and 75% (v/w) was held at 30 degrees C, 40 degrees C or 50 degrees C and examined over a 6 h period for cyanide content, pH and titratable acidity (TTA) . During the come-up time, i.e . the time between addition of water and attainment of desired holding temperature (between 14 and 47 min), reductions in bound cyanide of ca 54-85% occurred, depending on the level of added water and holding temperature . The corresponding losses for the control samples, to which no water was added, were ca 25-33% . The biggest reduction in the bound cyanide of > 99% (from 89.0 to 0.6 ppm) occurred in grated cassava with 75% added water held at 50 degrees C . There was little or no change in pH during the period of study . The reduction of processing time for certain cassava products based on separation into detoxication and flavour development/fermentation stages is discussed. Food Addit Contam, 1992 Jul-Aug, 9(4), 337 - 43 Factors affecting the results of T-2 mycotoxin ELISA assay; Laamanen I et al.; Certain substances in the sample may increase or decrease the reaction between the enzyme and substrate in ELISA assays . During a survey of T-2 trichothecene in food and animal feed 75% of milled grain samples gave a higher O.D . value in competitive T-2 toxin ELISA than the negative control . In samples spiked with small quantities (10 micrograms/kg) of T-2 toxin this type of reaction resulted in underestimates of toxin content . However, the effect was weak and, owing to the high sensitivity of the assay, it did not result in false negative reactions . The low efficiency of the carrier solvent and natural peroxidases in food and feed were considered to be the cause of the inaccurate reactions . A few fermented and processed foodstuffs and feed gave positive results in the T-2 toxin ELISA assay, but verification of the results by gas chromatography (GC) showed that the reactions were false . Certain substances in the samples destroyed or decreased the enzyme activity . False positive reactions can be distinguished from correct ones by retesting the extracts in different dilutions. Antibiot Khimioter, 1992 Jul, 37(7), 8 - 9 {Comparative evaluation of stability of benzylpenicillin in acid media of natural solutions and in culture fluid}; Peretokina NS et al.; Inactivation of benzylpenicillin in real media i.e . fermentation broths and their filtrates was studied in comparison with the published data on inactivation of commercial benzylpenicillin in aqueous solutions as dependent on the medium pH and temperature . The lowest constant of benzylpenicillin inactivation was shown to be in the fermentation broths. Antibiot Khimioter, 1992 Jul, 37(7), 10 - 3 {Destabilization of emulsions during extraction of antibiotics from natural solutions}; Peretokina NS et al.; Various means for changing the aggregative stability of emulsions in the system of benzylpenicillin fermentation broth filtrate and butyl acetate were tested . It was shown that the use of desemulgators was more efficient than the use of some means for removing the desemulgating admixtures . Moreover, addition of surface active substances after the preliminary thermocoagulation resulted in maximum decreasing of the emulsion aggregative stability. Yakugaku Zasshi, 1992 Jul, 112(7), 489 - 95 {Pharmacological study on kefir--a fermented milk product in Caucasus . I . On antitumor activity (1)}; Kubo M et al.; The antitumor activity of kefir (YK-1), a fermented milk product in Caucasus, was investigated . YK-1 at oral doses of 100 or 500 mg/kg inhibited the proliferation of solid tumor of Ehrlich ascites carcinoma transplanted subcutaneously in mice . YK-1 did not show an inhibitory effect on the ear swelling induced contact dermatitis caused by picryl chloride (PC-CD) . However, YK-1 inhibited the immunosuppression in Ehrlich carcinoma-bearing mice and with the frozen and dried ascites of the tumor-bearing mice containing immunosuppressive substances (EC-sup) in PC-CD-induced mice . And also, YK-1 activated the immunosuppressive activity of spleen cells of mouse treated with EC-sup . These results suggest that YK-1 may have antitumor activity against Ehrlich carcinoma and activate the immunosuppression with it. Can J Microbiol, 1992 Jul, 38(7), 626 - 34 Relationship of low lysine and high arginine concentrations to efficient ethanolic fermentation of wheat mash; Thomas KC et al.; Very high gravity wheat mashes containing 20 or more grams of carbohydrates per 100 mL were fermented completely by Saccharomyces cerevisiae, even though these mashes contained low amounts of assimilable nitrogen . Supplementation of wheat mashes with various amino acids or with yeast extract, urea, or ammonium sulfate reduced the fermentation time . However, lysine or glycine added as single supplements, inhibited yeast growth and fermentation . With lysine, yeast growth was severely inhibited, and a loss of cell viability as high as 80% was seen . Partial or complete reversal of lysine-induced inhibition was achieved by the addition of a number of nitrogen sources . All nitrogen sources that relieved lysine-induced inhibition of yeast growth also promoted uptake of lysine and restored cell viability to the level observed in the control . They also increased the rate of fermentation . Experiments with minimal media showed that for lysine to be inhibitory to yeast growth, assimilable nitrogen in the medium must be in growth-limiting concentrations or totally absent . In the presence of excess nitrogen, lysine stimulated yeast growth and fermentation . Results indicate that supplementing wheat mash with other nitrogen sources increases the rate of fermentation not only by providing extra nitrogen but also by reducing or eliminating the inhibitory effect of lysine on yeast growth. Br J Nutr, 1992 Jul, 68(1), 293 - 303 Effect of ileo-rectal anastomosis and post-valve T-caecum cannulation on growing pigs . 1 . Growth performance, N-balance and intestinal adaptation; Kohler T et al.; The effects of post-valve T-caecum (PVTC) cannulation and end-to-side ileo-rectal anastomosis (IRA) on growth performance, nitrogen retention and intestinal fermentation were measured in growing pigs by comparison with a control group of intact animals . There were no differences between PVTC-pigs and intact pigs in growth performance and N balance . In IRA-animals reduced growth (P < 0.01), less efficient feed conversion (P < 0.01) and decreased N retention (P < 0.001) were found . Indices of fermentation measured in ileal digesta of PVTC- and IRA-pigs were considerably different . In IRA-animals the concentration of volatile fatty acids (VFA) was about 112-162 mmol/l, higher (P < 0.001) than in digesta of PVTC-pigs (20-31 mmol/l) . The molar proportions of acetate and propionate depended (P < 0.01 and P < 0.001 respectively) on the digesta-collection technique . Concentrations and ratios of VFA measured in PVTC-pigs were similar to reported values . Diaminopimelic acid (DAPA) concentration and N:DAPA ratios measured in digesta were significantly (P < 0.05 and P < 0.001 respectively) different between treatments . All digesta variables measured showed increased microbial activity in digesta of IRA-pigs; thus, an influence on digestibility measurement can be assumed. Nihon Kyobu Shikkan Gakkai Zasshi, 1992 Jul, 30(7), 1215 - 21 {Nosocomial respiratory infection caused by Pseudomonas cepacia in immunocompromised hosts}; Fujita J et al.; Pseudomonas cepacia is a gram negative rod, having no fermentative activity on glucose . This organism was detected in the sputum, throat swab, or throat washing of 22 inpatients treated between January, 1990, and December, 1990, at the First Department of Internal Medicine, Kagawa Medical School . The primary diseases for which these 22 patients were hospitalized were leukemia in 12, malignant lymphoma in 5, lung cancer in 2, myelodysplastic syndrome in 1, and embryonal cell carcinoma in 1 . Twelve of the 22 patients had episodes of pneumonia which complied clinically with the diagnostic criteria provided to facilitate the National Nosocomial Infection Study . The complication of pneumonia occurred in 7 patients with leukemia, 2 with malignant lymphoma, 2 with lung cancer, and 1 with myelodysplastic syndrome . In 10 of these 12 patients, the organism was detected before the onset of pneumonia . All 22 patients in whom the organism was demonstrated had received antibiotics . The antibiotics which was most frequently used to treat these patients 1 month before detection of Pseudomonas cepacia were amikacin and ceftizoxime, which were used in 13 patients . Of the antibiotics in which the susceptibility to Pseudomonas cepacia was, evaluated, minocycline was effective in 100% (21/21), ceftazidime in 50% (11/22), and ofloxacin in 27.3% (6/22) . Physicians should be especially aware of the possibility of colonization and nosocomial respiratory infection by Pseudomonas cepacia in patients with severe underlying diseases. J Antibiot (Tokyo), 1992 Jul, 45(7), 1055 - 63 WS9326A, a novel tachykinin antagonist isolated from Streptomyces violaceusniger no . 9326 . I . Taxonomy, fermentation, isolation, physico-chemical properties and biological activities; Hayashi K et al.; Data from several studies suggest that tachykinins may play an important role in the pathophysiology of airway diseases, especially asthma . Our aim is to discover tachykinin antagonists which exhibit therapeutically useful anti-asthmatic activity . In our search for activities inhibiting the binding of {3H}substance P to guinea-pig lung membrane preparations, we have found that the fermentation product, WS9326A, isolated from Streptomyces violaceusniger, is a potent tachykinin receptor antagonist. Biotechnol Prog, 1992 Jul-Aug, 8(4), 307 - 15 Bioprocess development to improve foreign protein production from recombinant Streptomyces; DelaCruz N et al.; Bioprocessing strategies to improve production of the heterologous protein parathion hydrolase from recombinant Streptomyces lividans were investigated . Initial limitations to increased production were overcome by using large amounts of nutrients and feeding these nutrients throughout the fermentation . Batch addition of such large amounts of nutrients resulted in byproduct acid accumulation . Our data suggest that byproducts resulted from incomplete utilization of peptide medium ingredients and not from an overflow of glucose catabolism . Over extended fed-batch operation, oxygen transfer became limiting and these limitations were overcome by sparging oxygen-enriched gas . When cultivation was continued past about 90 h, we observed that despite nutrient feeding and oxygen enrichment enzyme activities no longer increased . Our results show that during such late cultivation periods the rates of enzyme synthesis and deactivation became balanced . If synthesis is prevented, either by a nutritional limitation or by the addition of the protein synthesis inhibitor chloramphenicol, enzyme activities were observed to decrease . Since deactivation rate constants in these experiments were similar to those observed in cell-free studies, and because extracellular protease activities were not detected in our fermentation, it appears that deactivation results from the inherent instability of the parathion hydrolase enzyme. Biotechnol Prog, 1992 Jul-Aug, 8(4), 369 - 74 Monitoring intracellular protein profiles with two-dimensional gel electrophoresis; Dykstra KH et al.; Two-dimensional polyacrylamide gel electrophoresis (2D PAGE) is a method of separating complex protein mixtures, such as whole cell extracts, on the basis of protein isoelectric point and molecular weight . In bioprocess engineering, conventional 2D PAGE has tremendous potential to yield detailed information on the intracellular effect of various process conditions . It has been used in our work to examine global intracellular changes occurring in a typical cycloheximide fermentation and to look at the feedback regulatory behavior of cycloheximide biosynthesis . Application of the technique for bioprocess monitoring will require that the time necessary for preparation of a 2D electropherogram be substantially shortened . This may be accomplished by performing the separation on a miniature scale or eventually by use of capillary electrophoresis for one or more of the separations . Advantages and disadvantages of these two approaches are discussed. Biotechnol Prog, 1992 Jul-Aug, 8(4), 285 - 90 Effect of oxygen supply on the suspension culture of genetically modified tobacco cells; Gao J et al.; The effect of oxygen supply on the cultivation of the genetically modified tobacco cells and the formation of a foreign protein, beta-glucuronidase (GUS), was investigated in 250-mL Erlenmeyer flasks, a 5-L stirred tank fermenter, and a 7-L air-lift fermenter . The oxygen supply was varied by using different volumes of medium in the case of the 250-mL Erlenmeyer flask culture or by the different aeration rate in the case of the two types of fermenters tested . Higher oxygen supply stimulated cell growth and increased oxygen consumption rate, the level of phenolics, and GUS productions. J Antibiot (Tokyo), 1992 Jul, 45(7), 1079 - 83 Benarthin: a new inhibitor of pyroglutamyl peptidase . I . Taxonomy, fermentation, isolation and biological activities; Aoyagi T et al.; We found benarthin, a new inhibitor of pyroglutamyl peptidase, in the fermentation broth of Streptomyces xanthophaeus MJ244-SF1 . It was purified by column chromatography and centrifugal partition chromatography (CPC) and then was isolated as a colorless powder . The binding of benarthin was competitive with substrate and its inhibition constant (Ki) was 1.2 x 10(-6) M. J Antibiot (Tokyo), 1992 Jul, 45(7), 1029 - 40 WS009 A and B, new endothelin receptor antagonists isolated from Streptomyces sp . no . 89009 . I . Taxonomy, fermentation, isolation, physico-chemical properties and biological activities; Miyata S et al.; WS009 A and B novel endothelin receptor antagonists, have been isolated from the fermentation broth of Streptomyces sp . No . 89009 . These antagonists were purified from the culture filtrate followed by Diaion SP-207, DEAE Toyopearl column chromatography and HPLC . WS009 A and B showed selective activity in an endothelin receptor binding assay with IC50 of 5.8 x 10(-6) M and 6.7 x 10(-7) M, respectively . On the basis of spectroscopic and chemical evidence, the structures of WS009 A and B have been established as 1 and 3, and are highly hydroxylated benz{a}anthraquinone chromophores. J Chromatogr, 1992 Jun 26, 604(1), 143 - 55 Production, purification and characterization of recombinant human interferon gamma; Zhang Z et al.; An essentially three-step chromatographic purification procedure, i.e., ion-exchange, immobilized metal ion affinity and size-exclusion chromatography, is described for the purification to homogeneity of recombinant human interferon-gamma (rhIFN-gamma) from the inclusion bodies produced in genetically transformed Escherichia coli cells . Batchwise adsorption of the cloudy solution of renatured rhIFN-gamma obviated the need for high-speed centrifugation to clarify the suspension . This step effectively removed about 70% of extraneous protein impurities . The established purification process is reproducible and leads to a total recovery of 32% . Pilot-scale processing of E . coli cells grown in a 30-l fermentor gave about 70 mg of a homogeneous preparation of rhIFN-gamma . The specific biological activity of purified rhIFN-gamma is ca . 3.4 x 10(7) I.U./mg protein, which is comparable to that of its natural counterpart . It is basic protein (pI greater than pH 9) with a monomer relative molecular mass of 15,000 . It behaves, however, as a dimer on size-exclusion chromatography . Its partial NH2-terminal sequence is identical with that established for the rhIFN-gamma . However, its amino acid composition and its relative molecular mass (15,067 as determined by electrospray mass spectrometry) indicate that the purified protein is a truncated form lacking fifteen amino acid residues from its carboxyl-terminal side . This modification does not seem to have any adverse effect on its biological potency . The levels of DNA, bacterial endotoxins and Ni(II) ions in the final product were determined. J Chromatogr, 1992 Jun 26, 604(1), 157 - 70 Purification, characterization and crystallization of recombinant HIV-1 reverse transcriptase; Bhikhabhai R et al.; The pol I gene from HIV-1 encoding the protease, reverse transcriptase (RT) and endonuclease has been expressed in Escherichia coli . By modifying the fermentation conditions and developing a new purification scheme, the yield of purified RT has been increased substantially compared with that obtained in an earlier procedure . The expressed RT was purified to homogeneity by ammonium sulphate fractionation followed by chromatography on DEAE Sepharose, Heparin Sepharose, S Sepharose and Poly(A)-Sepharose . The purified HIV-RT is a heterodimer (p66/p51) with an isoelectric point close to 8 and with a tendency to aggregate . The proteolytic product (p51), corresponding to the N-terminal end of the RT molecule, was isolated and identified, as were also some bacterial polypeptides that co-elute with HIV-RT during the early stages of the purification . The heterodimer was crystallized in several morphological forms using the vapour-diffusion hanging drop technique . To concentrate the protein and to change the buffer for crystallization, reverse-salt-gradient chromatography and micropreparative columns were used . The best crystals diffracted to 9 A resolution . The best crystals of native RT diffracted to 9 A resolution and in complex with nucleic acids to 4.5 A resolution (using a rotating anode X-ray source). Proc R Soc Lond B Biol Sci, 1992 Jun 22, 248(1323), 283 - 9 Isolation of deacetoxycephalosporin C from fermentation broths of Penicillium chrysogenum transformants: construction of a new fungal biosynthetic pathway; Cantwell C et al.; Deacetoxycephalosporin C (DAOC), a precursor of cephalosporins excreted by Cephalosporium and Streptomyces species, has been produced in Penicillium chrysogenum transformed with DNA containing a hybrid penicillin N expandase gene (cefEh) and a hybrid isopenicillin N epimerase gene (cefDh) . DAOC from a P . chrysogenum transformant was identified by ultraviolet light (UV), high performance liquid chromatography (HPLC), nuclear magnetic resonance (NMR) and mass spectrum analyses . P . chrysogenum transformed with DNA containing cefEh without cefDh did not produce DAOC . Untransformed P . chrysogenum produced penicillin V (phenoxymethylpenicillin) but not DAOC . Transformants also produced penicillin V but, in general, less than untransformed P . chrysogenum . The cefEh and cefDh genes were constructed by replacing the open reading frame (ORF) of cloned P . chrysogenum pcbC and penDE genes with the ORF of the Streptomyces clavuligerus expandase gene, cefE, and the ORF of the Streptomyces lipmanii epimerase gene, cefD, respectively . Analyses of representative transformants suggested that production of DAOC occurred via cefEh and cefDh genes stably integrated in the P . chrysogenum genome . DNA from untransformed P . chrysogenum did not hybridize to cefE or cefD gene probes. Gene, 1992 Jun 15, 115(1-2), 201 - 11 Actinomycete infections in humans--a review; Schaal KP et al.; Diseases caused by pathogenic aerobic and facultatively anaerobic actinomycetes differ considerably with respect to their etiology, pathogenesis, clinical appearance and epidemiology . Facultatively anaerobic (fermentative) actinomycetes may not only be involved etiologically in the three classical forms of cervicofacial, thoracic and abdominal actinomycoses, but also in infections of the female genital organs, the eye, the tissue adjacent to dental implantation elements and tooth extraction wounds . The species distribution of the fermentative actinomycetes isolated from these conditions varied to a certain, but characteristic, extent, as did the concomitant actinomycotic flora . The sex ratio reported for human Actinomyces infections (male:female = 3:1) appeared to be restricted to actinomycotic abscesses and empyemas . The prevailing pathogenic, obligately aerobic actinomycete species in Germany was found to be Nocardia farcinica followed by Nocardia asteroides . The comparatively high incidence of N . farcinica infections was chiefly due to the occurrence of nosocomial postoperative wound infections by this pathogen observed in two German hospitals . Besides surgical treatment, immunosuppressive treatment appeared to be the most common factor predisposing for nocardiosis . Recent observations strongly suggested that the spectrum of human nocardial infections in Germany has been changing, as regards the overall incidence, the prevalence of N . farcinica, the sex ratio, the mean age of patients, as well as the role of N . farcinica as a possibly important nosocomial pathogen. J Biol Chem, 1992 Jun 15, 267(17), 11705 - 8 Squalestatin 1, a potent inhibitor of squalene synthase, which lowers serum cholesterol in vivo; Baxter A et al.; Squalestatin 1 is a member of a novel family of fermentation products isolated from a previously unknown Phoma species (Coelomycetes) . Squalestatin 1 is a potent, selective inhibitor of squalene synthase, a key enzyme in cholesterol biosynthesis; in vitro, 50% inhibition of enzyme activity is observed at a concentration of 12 +/- 5 nM (range of 4-22 nM) . Squalestatin 1 inhibits cholesterol biosynthesis from {14C}acetate by isolated rat hepatocytes (50% inhibition at 39 nM) and by rat liver in vivo . In marmosets, a species with a lipoprotein profile similar to that of man, squalestatin 1 lowers serum cholesterol by up to 75% . This compound will allow further investigation of the control of the sterol biosynthesis pathway and could also lead to the development of new therapies for elevated serum cholesterol. J Clin Microbiol, 1992 Jun, 30(6), 1402 - 6 Fluorogenic substrates for differentiation of gram-negative nonfermentative and oxidase-positive fermentative bacteria; Kampfer P et al.; A total of 803 strains of gram-negative nonfermentative and oxidase-positive fermentative bacteria (38 taxa) were investigated for their ability to hydrolyze 53 different fluorogenic 4-methylumbelliferyl- and beta-naphthylamide-linked substrates within 6 h of incubation . The hydrolysis of 16 fluorogenic substrates showed high separation index values among the tested taxa, was reproducible, and showed good agreement with data in the literature . In combination with other biochemical tests (like carbon substrate utilization tests and classical biochemical tests), hydrolysis profiles can improve the differentiation of gram-negative nonfermentative and oxidase-positive fermentative bacteria. Am J Physiol, 1992 Jun, 262(6 Pt 2), R939 - 46 Short-term effect of aldosterone on Na-Cl transport across equine colon; Clarke LL et al.; In ponies fed concentrated (pelleted) meals, postprandial increases of plasma aldosterone have been temporally associated with a decrease in colonic fluid volume that parallels the conclusion of postfeeding fermentation . To determine the significance of short-term increases of plasma aldosterone on the rate of colonic Na absorption, in vitro transport studies were conducted on the mucosae of three morphologically distinct colonic segments (i.e., ventral, dorsal, and small colons) from ponies infused with a high physiological concentration of aldosterone for an 8-h period . In control ponies, basal NaCl absorption across the proximal colon (ventral and dorsal colons) was amiloride-insensitive and electroneutral . In aldosterone-treated ponies, the rate of electroneutral Na absorption was doubled in both segments and a small, amiloride-sensitive current was detected in the dorsal colon . However, consistent with previous observations {Clarke and Argenzio . Am . J . Physiol . 259 (Gastrointest . Liver Physiol . 22): G62-G69, 1990}, expression of electroneutral Na absorption in the ventral colon required pretreatment of the tissues with an inhibitor of prostaglandin synthesis, i.e., indomethacin . In the distal (small) colon, basal absorption was entirely electrogenic and amiloride-sensitive, and aldosterone treatment tripled the rate of absorption . The above findings are consistent with the notion that postprandial hyperaldosteronism can significantly increase colonic Na absorption and, thereby, may facilitate colonic fluid absorption during the concluding period of meal-induced fermentation (8-12 h postfeeding) . However, in the ventral colon (i.e., the principal site of fermentation), mineralocorticoid action does not dominate control of electroneutral Na transport because accelerated absorption could be abolished by the antiabsorptive effect of local prostanoids. Mol Gen Genet, 1992 Jun, 233(3), 363 - 71 A new member of the adenylate kinase family in yeast: PAK3 is highly homologous to mammalian AK3 and is targeted to mitochondria; Schricker R et al.; Making use of the polymerase chain reaction primed by oligonucleotides corresponding to regions conserved between members of the nucleoside monophosphate kinase family, we have isolated the yeast gene PAK3 . Pak3p belongs to the subgroup of long-form adenylate kinase isozymes (deduced molecular mass 25.3 kDa) and exhibits highest sequence similarity to bovine AK3 rather than to the yeast isozyme, Aky2p . The gene is shown to be non-essential because haploid disruption mutants are viable, both in the presence and absence of a functional AKY2 allele . It maps on chromosome V upstream of RAD3 . Its expression level is low when cells are grown on glucose or other fermentable carbon sources and about threefold higher on glycerol, but can be significantly induced by ethanol . A PAK3/mouse dihydrofolate reductase fusion construct expressed in yeast is targeted to mitochondria . Transformation with PAK3 on a multicopy plasmid complements neither adenylate kinase deficiency in an aky2-disrupted yeast strain nor in Escherichia coli cells conditionally defective in adenylate kinase. Heredity, 1992 Jun, 68 ( Pt 6), 515 - 28 Remating effects on the genetic structure of female life histories in populations of Drosophila mojavensis; Etges WJ et al.; A quantitative genetic analysis of nine adult fitness components was performed in two populations of cactophilic Drosophila mojavensis under natural conditions of fermenting cactus and ethanol vapour . Female progeny from 18 sires and 36 dams were treated to a range of six exposure periods to males to assess effects of remating frequency on female fitness . Lifetime fecundity increased with increasing male exposure, but longevity showed an intermediate optimum with temporary exposure to males of 2-4 days . Narrow-sense heritabilities were significant for egg production traits while broad-sense heritabilities were significant for longevity-related traits . Positive genetic correlations between components of fitness were expressed among functionally related traits, e.g . longevity was positively correlated with lifetime fecundity, the number of clutches laid, clutch size, and the number of eggs laid per day . Negative genetic correlations were detected between early and late life fecundity suggesting genetic tradeoffs among components of adult fitness. FEBS Lett, 1992 Jun 1, 303(2-3), 251 - 4 Fusion of Mycoplasma fermentans strain incognitus with T-lymphocytes; Franzoso G et al.; The ability of Mycoplasma fermentans (strain incognitus) to fuse with cultured lymphocytes was investigated and the fusion process was characterized . Fusion was measured using an assay to determine lipid mixing based on the dequenching of the fluorescent probe, octadecylrhodamine (R18), that was incorporated into the mycoplasma cells . Fusion of M . fermentans was detected with both CD4+ (Molt 3) and CD4- (12-E1) cells . The amount of fusion induced was relatively low and ranged from 5-10% with either cell culture . When primary peripheral blood lymphocytes were used the fusion yield was somewhat higher, reaching 12% of the cell population . Similar findings were obtained with fluorescent microscopy analysis suggesting that a predetermined, but unidentified subpopulation of cultured lymphocytes, were being fused . The rate of fusion was temperature dependent . Following a short lag period fusion at 37 degrees C was virtually completed in 60 min . The lymphocytes remained intact throughout the fusion process, as determined by the Trypan blue staining procedure . Fusion was almost completely inhibited by anti-M . fermentans antisera and by pretreatment of M . fermentans cells with proteolytic enzymes, suggesting that a surface-exposed proteinaceous component is involved in the fusion process. EMBO J, 1992 Jun, 11(6), 2357 - 64 Hsp104 is required for tolerance to many forms of stress; Sanchez Y et al.; Heat-shock proteins (hsps) are induced by many types of stress . In Saccharomyces cerevisiae, a mutation in the HSP104 gene, a member of the highly conserved hsp100 gene family, reduces the ability of log-phase fermenting cells to withstand high temperatures after mild, conditioning pretreatments . Here, we examine the expression of hsp104 and its importance for survival under many different conditions . Hsp104 is expressed at a higher level in respiring cells than in fermenting cells and is required for the unusually high basal thermotolerance of respiring cells . Its expression in stationary phase cells and spores is crucial for the naturally high thermotolerance of these cell types and for their long-term viability at low temperatures . The protein is of critical importance in tolerance to ethanol and of moderate importance in tolerance to sodium arsenite . Thus, the hsp104 mutation establishes the validity of a long-standing hypothesis in the heat-shock field, namely, that hsps have broadly protective functions . Further, that a single protein is responsible for tolerance to heat, ethanol, arsenite and long-term storage in the cold indicates that the underlying causes of lethality are similar in an extraordinary variety of circumstances . Finally, the protein is of little or no importance in tolerance to copper and cadmium, suggesting that the lethal lesions produced by these agents are fundamentally different from those produced by heat. Am J Gastroenterol, 1992 Jun, 87(6), 751 - 6 Evidence for colonic conservation of malabsorbed carbohydrate in short bowel syndrome; Royall D et al.; The purpose of this study was to determine whether energy from malabsorbed carbohydrate could be conserved through colonic fermentation in short bowel syndrome . Seven patients with short bowel anastomosed to the remaining colon and five patients with short bowel without a colon were selected from the home total parenteral nutrition (TPN) program . Six normal volunteers also were studied . After an overnight fast, subjects consumed a 50-g carbohydrate bread meal and were studied hourly over the next 6 h . Carbohydrate malabsorption, estimated by lactulose breath hydrogen testing, was 48 +/- 13% in short bowel patients . After the bread meal, breath hydrogen was higher in short bowels with colons (69 +/- 20 ppm) than in either short bowels without colons (11 +/- 7 ppm) or normal subjects (10 +/- 3 ppm) (p less than 0.01) . Blood acetate levels also were higher in short bowels with colons than in those without colons, reaching a peak of 167 +/- 27 mumol/L at 4 h (p less than 0.05) . We conclude that in patients with a short bowel and a colon, malabsorbed carbohydrate is fermented and there is a rise in blood acetate, suggesting that the colon has a role in salvaging malabsorbed carbohydrate as a source of energy through carbohydrate fermentation. J Dairy Sci, 1992 Jun, 75(6), 1736 - 44 Effect of direct-fed microbials on rumen microbial fermentation; Martin SA et al.; Nonbacterial, direct-fed microbials added to ruminant diets generally consist of Aspergillus oryzae fermentation extract, or Saccharomyces cerevisiae cultures, or both . Results from in vivo research have been variable regarding effects of direct-fed microbials on ruminant feedstuff utilization and performance . Some research has shown increased weight gains, milk production, and total tract digestibility of feed components, but others have shown little influence of direct-fed microbials on these parameters . In vitro research with mixed ruminal microorganisms likewise has been inconsistent regarding the effects of direct-fed microbials . Several researchers observed that direct-fed microbials increased cellulolytic bacterial numbers in the rumen and stimulated the production of some fermentation end products . This suggests that direct-fed microbials may be providing growth factors for the ruminal microbes . However, other researchers have reported no effect of direct-fed microbials on in vitro fiber digestion . Recent research demonstrated that growth of the predominant ruminal bacterium Selenomonas ruminantium in lactate medium as well as lactate uptake by whole cells of Sel . ruminantium were markedly increased by an A . oryzae fermentation extract and an S . cerevisiae culture . In addition, both products increased the production of acetate, propionate, succinate, total VFA, and cell yield (grams of cells per mole of lactate) . Therefore, it appears that these direct-fed microbials provide soluble factors that stimulate lactate utilization by Sel . ruminantium . Evidence is presented indicating that the malate content of the A . oryzae fermentation extract and S . cerevisiae culture may be involved in this stimulation. J Dairy Sci, 1992 Jun, 75(6), 1616 - 21 Influence of feeding varying levels of Amaferm on performance of lactating dairy cows; Denigan ME et al.; Amaferm, a fermentation extract of Aspergillus oryzae, was fed as a top-dressing to dairy cows at 0, 1.5, 3, and 6 g/d in two lactation trials using 64 cows in 1989 . Lactation trial 1 was conducted in the spring (March to May) and used 40 cows averaging 75 DIM for a 70-d treatment period . Lactation trial 2 was during the summer (June to July) . Twenty-four cows averaging 140 DIM were employed in a 60-d study . Measurements included milk yield, feed intake, BW, rectal temperatures, respiration rate, and digestibility of CP, NDF, and DM . None of the levels of Amaferm had a significant effect on milk yield or composition, BW changes, or digestion coefficients in either trial . Cows fed 1.5 g/d of Amaferm had a higher DMI than those receiving 0 or 6 g in trial 1, and respiration rates were significantly higher for cows fed 3 g/d of Amaferm in trial 2 . Under the conditions of this study, none of the levels of Amaferm affected the performance of lactating cows . Further elucidation of factors influencing response to Amaferm is needed. J Antibiot (Tokyo), 1992 Jun, 45(6), 914 - 21 Herboxidiene, a new herbicidal substance from Streptomyces chromofuscus A7847 . Taxonomy, fermentation, isolation, physico-chemical and biological properties; Miller-Wideman M et al.; Screening of microbial fermentation broths for herbicidal activity led to the discovery of a novel polyketide, herboxidiene, from an actinomycete identified as a member of the Streptomyces chromofuscus cluster . A 14- to 20-fold increase in fermentation production of herboxidiene was achieved as a result of media optimization . Herboxidiene was purified using successive reverse phase C18 steps and Sephadex LH-20 chromatography . Its molecular formula, C25H42O6, was determined by HRFAB-MS . Herboxidiene demonstrated exceptionally potent, selective, herbicidal activity against a variety of weed species and was inactive against wheat, even at rates as high as 5.6 kg/hectare. J Antibiot (Tokyo), 1992 Jun, 45(6), 899 - 905 Leualacin, a novel calcium blocker from Hapsidospora irregularis . I . Taxonomy, fermentation, isolation, physico-chemical and biological properties; Hamano K et al.; A new calcium blocker, designated leualacin, has been isolated from Hapsidospora irregularis . The compound inhibits the binding of 3H-nitrendipine, a well known synthetic calcium blocker, to cardiac Ca channel in a competitive manner, although its structure is completely different from dihydropyridines. J Antibiot (Tokyo), 1992 Jun, 45(6), 892 - 8 PI-200 and PI-201, new platelet aggregation inhibitors produced by Streptomyces sp . A7498 . Taxonomy, fermentation, isolation, physico-chemical properties, structure determination and biological properties; Kishimura Y et al.; Two new platelet aggregation inhibitors, PI-200 and PI-201 were isolated from the fermentation broth of Streptomyces sp . A7498 . PI-200 and PI-201 inhibited ADP-induced aggregation of rabbit platelets with an IC50 of 3.8 x 10(-4) M and 7.1 x 10(-4) M, respectively. J Antibiot (Tokyo), 1992 Jun, 45(6), 846 - 53 SF2457, a new antibiotic related to amicetin; Itoh J et al.; A novel nucleoside antibiotic, SF2457, was isolated from the fermentation broth of Nocardia brasiliensis SF2457 . The structure of SF2457 was determined by degradation studies using alkaline hydrolysis and methanolysis . SF2457 is closely related to the amicetin group antibiotics . The antibiotic exhibited inhibitory activity against Gram-positive and Gram-negative bacteria. J Nutr Sci Vitaminol (Tokyo), 1992 Jun, 38(3), 287 - 96 Qualitative and quantitative estimation of soluble indigestible polysaccharides as substrate for hindgut fermentation by mini-scale batch culture; Kikuchi H et al.; Pectin, guar gum, transgalactosylated oligosaccharide and glucose were estimated as substrate for hindgut fermentation by measuring the volume of gas released from a 1 ml scale batch culture using rat cecal contents . The amount of short-chain fatty acids (SCFA) in cultures of glucose and pectin was also measured . The amount of SCFA (Y mumol/culture) or volume of gas released (Y ml/culture) was expressed as an exponential function of incubation time (t) (Y = A+B x (1-e-kt); A, B and k are constants) . The amount of potential production of gas and SCFA (B) for glucose was higher than that for pectin and the rate constant of gas and SCFA (k) for pectin was higher than that for glucose . The volume of gas released (ml/culture) correlated positively and linearly with the amount of total SCFA (acetic, propionic and n-butyric acids, mumol/culture) . A single regression stood for both glucose and pectin . The gas release followed saturation kinetics . The half maximal concentration and maximal velocity for gas release from pectin were higher than those from other substrates (glucose, guar gum and transgalactosylated oligosaccharide). Shi Yan Sheng Wu Xue Bao, 1992 Jun, 25(2), 157 - 63 {Studies on genetic engineering of human insulin-purification and characterization of human proinsulin and insulin}; Guo LH et al.; E . coli DH 5 alpha cells harboring a plasmid pWR 590-BCA 4 for fused human proinsulin production were cultured . The fused human proinsulin was isolated from the fermented cells and then subjected it to cleavage with BrCN . The cleaved product was then converted to crude proinsulin-S-sulfonate using oxidative sulfitolysis . The isolation of human proinsulin-S-sulfonate was accomplished by ion exchange chromatography on QAE-sephadex A-25, followed by gel filtration on sephadex G-50 . The purified human proinsulin-S-sulfonate was folded using a disulfide interchange method . The folding mixture was then chromatographed on sephadex G-50 and purified proinsulin was obtained . The proinsulin was then converted to human insulin and C-peptide by a combination cleavage with trypsin and carboxypeptidase B . The total yield of human insulin was about 5 mg/L The Zinc insulin crystals were obtained with amorphous human insulin using citrate method . The amino acid composition N-terminal sequences as well as C-terminal amino acid residues are in agreement with expected results . The hypoglycemic activity of purified human insulin is 26-27 U/mg, as judged by mouse convulsion assay, and the RIA activity is about 99% of that of porcine insulin. J Protein Chem, 1992 Jun, 11(3), 213 - 23 High-level expression of recombinant human FK-binding protein from a fusion precursor; Edalji R et al.; The human peptidyl-prolyl isomerase FK-binding protein (FKBP) was cloned as a fusion partner with CMP-KDO synthetase (CKS), and the resultant construct was characterized as an improved high-expression source for FKBP . The CKS-FKBP fusion was expressed as a soluble protein at levels approaching 1 gm/L in Escherichia coli fermentations . The fusion protein was purified to near homogeneity by a one-step ammonium sulfate fractionation of whole cell lysate . After selective cleavage, the fusion precursor produced yields approaching 300 mg of purified FKBP per liter of harvested culture, a approximately 30 to 60-fold increase over that observed for a nonfusion construct . Selective cleavage of the fusion partners was accomplished using either hydroxylamine or specific, limited proteolysis . Once separated from the CKS fusion partner, the FKBP was isolated in a single step by either reversed-phase HPLC or chromatography on Q-Sepharose . For comparison of physical and chemical properties, a nonfusion construct of recombinant human FKBP was expressed in E . coli and isolated . The purified FKBPs exhibited expected SDS-PAGE molecular weights and N-terminal sequences . The proteins had similar proton NMR spectra and binding to {3H}FK-506 . The fusion construct, CKS-FKBP, was also found to bind {3H}FK-506 . These data indicate that FKBP fused to the C-terminus of CKS folds independently of the fusion partner and suggests the fused FKBP adopts a conformation resembling that of the native protein. J Dairy Sci, 1992 Jun, 75(6), 1581 - 7 Development of buffer systems for pH control and evaluation of pH effects on fiber digestion in vitro; Grant RJ et al.; An in vitro buffering system capable of pH control between pH 5.8 and 6.8 was developed to examine the effect of media pH on disappearance of NDF at various times of fermentation and to assess initially the effect of media pH on kinetics of NDF digestion . The pH conditions selected for evaluation of these buffer systems were 5.8, 6.2, and 6.8 . Use of McIlvaine's solution with sodium bicarbonate was not successful because of rapid drifting of pH downward during fermentation . To evaluate the effectiveness of citric or phosphoric acids as components of phosphate-bicarbonate buffer systems, alfalfa silage and a mixture of alfalfa silage and corn grain (1:1 mixture, dry basis) were fermented for 0, 12, 24, 48, and 72 h . The pH of each flask was measured at 0, 4, 12, 24, 48, and 72 h postinoculation, and pH was readjusted with bicarbonate solution when necessary . Drifting of media pH downward was more noticeable when phosphoric acid was used to adjust the buffer pH than with citric acid . Citric acid had no adverse effects on NDF digestion compared with phosphoric acid when used to adjust a phosphate-bicarbonate buffer system . Alfalfa hay, bromegrass hay, and corn silage were incubated for 0, 12, 2