Am J Vet Res, 2000 Aug, 61(8), 858 - 61 In vitro evaluation of intraluminal factors that may alter intestinal permeability in ponies with carbohydrate-induced laminitis; Weiss DJ et al.; OBJECTIVES: To study the in vitro effects of cecal contents incubated with corn starch on colonic permeability in horses . ANIMALS: 4 healthy adult ponies . PROCEDURE: Mucosal specimens were obtained from the right ventral colon and mounted in Ussing chambers . Changes in short circuit current, conductance, and large-molecule permeability in response to addition of cecal contents and cecal contents incubated with corn starch were evaluated for 120 minutes . RESULTS: Incubation of cecal contents with corn starch for 8 hours resulted in a decrease in cecal content pH and an increase in lactic acid concentration . These changes were similar to those reported in vivo for ponies given corn starch . Exposure of colonic mucosa to cecal contents incubated with corn starch resulted in an increase in tissue conductance and permeability of technetium Tc 99m pentetate, compared with mucosa exposed to cecal contents alone . CONCLUSIONS AND CLINICAL RELEVANCE: In vitro exposure of colonic mucosa to cecal contents incubated with starch resulted in increased paracellular permeability . Fermentation of excessive amounts of carbohydrate in the intestinal lumen of horses may directly induce increased intestinal permeability associated with carbohydrate-induced laminitis. J Biotechnol, 2000 Jul 14, 80(3), 271 - 6 Repeated-batch production of pigments by immobilised Monascus purpureus; Fenice M et al.; Extracellular pigment production by immobilised Monascus purpureus C322 has been studied in repeated-batch processes using different immobilising carriers such as Ca-alginate, polyurethane sponge, active carbon and pearlite . With Ca-alginate, pigment production was maximum (30.5 UA470 as process mean production, three batches) while the cell leakage was negligible (0.4 g 1(-1) free biomass) and the bead mechanical stability good; with this carrier, an extended repeated-batch fermentation (nine batches, 55 days) was carried out: the process pigment productivity was 3.87 UA470 day(-1). Am J Bot, 2000 Aug, 87(8), 1081 - 1090 Fate of oxygen losses from Typha domingensis (Typhaceae) and Cladium jamaicense (Cyperaceae) and consequences for root metabolism; Chabbi A et al.; The objective of this work was to determine whether radial oxygen loss (ROL) from roots of TYPHA: domingensis and CLADIUM: jamaicense creates an internal oxygen deficiency or, conversely, indicates adequate internal aeration and leakage of excess oxygen to the rhizosphere . Methylene blue in agar was used to visualize the pattern of ROL from roots, and oxidation of a titanium-citrate solution was used to quantify rates of oxygen leakage . TYPHA:'s roots had a higher porosity than CLADIUM:'s and responded to flooding treatment by increasing cortical air space, particularly near the root tips . A greater oxygen release, which occurred along the subapical root axis, and an increase in rhizosphere redox potential (E(h)) over time were associated with the well-developed aerenchyma system in TYPHA: Typha roots, regardless of oxygen release pattern, showed low or undetectable alcohol dehydrogenase (ADH) activity or ethanol concentrations, indicating that ROL did not cause internal deficiencies . CLADIUM: roots also released oxygen, but this loss primarily occurred at the root tips and was accompanied by increased root ADH activity and ethanol concentrations . These results support the hypothesis that oxygen release by CLADIUM: is accompanied by internal deficiencies of oxygen sufficient to stimulate alcoholic fermentation and helps explain CLADIUM:'s lesser flood tolerance in comparison with TYPHA: J Anim Sci, 2000 Aug, 78(8), 2215 - 22 Influence of feed intake fluctuation and frequency of feeding on nutrient digestion, digesta kinetics, and ruminal fermentation profiles in limit-fed steers; Soto-Navarro SA et al.; Nine crossbred beef steers (344 +/- 26 kg) fitted with ruminal cannulas were used in a randomized complete block design to evaluate the effects of feeding frequency and feed intake fluctuation on total tract digestion, digesta kinetics, and ruminal fermentation profiles in limit-fed steers . In Period 1, steers were allotted randomly to one of four dietary treatments: 1) feed offered once daily at 0800; 2) feed offered once daily at 0800 with a 10% fluctuation in day-to-day feed intake; 3) feed offered twice daily at 0800 and 1700; and 4) feed offered twice daily at 0800 and 1700 with a 10% fluctuation in a day-to-day feed intake . In Period 2, steers were reallocated across treatments . The 90% concentrate diet was fed at 90% of the ad-libitum consumption by each steer . Chromium-EDTA and Yb-labeled steam-flaked corn were intraruminally infused at 0800 on d 1 and 3 and Co-EDTA and Er-labeled steam-flaked corn were infused on d 2 and 4 of the 4-d collection period . Ruminal samples were collected at 0, 3, 6, 9, 12, 15, 18, and 24 h after the 0800 feeding, and total feces were collected for 4 d . Total tract digestibilities of OM, N, and starch were lowest (fluctuation x frequency, P < .05) when feed was offered twice daily with a 10% fluctuation in intake . Ruminal fluid volume and passage rate were not affected (P > .10) by feeding frequency or intake fluctuation . A frequency x fluctuation x sampling time interaction occurred (P < .01) for ruminal pH . Steers fed a constant amount of feed once daily had higher (P < .05) ruminal pH at 0, 3, 18, and 24 h than steers fed once daily with a 10% fluctuation in feed intake . Total VFA concentration was greater (P < .01) at 9 h after the 0800 feeding when feed was offered once vs twice daily . Feeding twice daily increased (P < .05) the molar proportion of acetate and decreased (P < .05) the molar proportion of propionate . Increasing feeding frequency resulted in a more stable ruminal environment; however, the increased acetate:propionate ratio with twice-daily feeding might result in lower efficiency of energy utilization by limit-fed steers. J Anim Sci, 2000 Aug, 78(8), 2032 - 8 Effects of planting density and processing method on laboratory characteristics of grain sorghum for ruminants; Defoor PJ et al.; Grain sorghum grown in 38-cm (high-density) or 76-cm rows (normal-density) was steam-flaked, harvested as high-moisture grain followed by rolling and ensiling, or dry-rolled . Chemical composition, enzymatic starch availability, CP insolubility, and IVDMD in a reduced-strength buffer were evaluated . High-density planting increased (P < .10) OM and starch concentration and decreased (P < .0001) CP concentration but did not affect (P > .10) P concentration, enzymatic starch availability, or CP insolubility . High-density planting resulted in lower (P < .10) in vitro ruminal culture pH at 6, 12, and 18 h of incubation when grain sorghum was processed by steam flaking, and lower (P < .10) IVDMD at 6, 12, and 18 h of digestion when grain sorghum was processed by dry rolling . Steam flaking decreased (P < .10) CP concentration and solubility and increased (P < .10) OM concentration . High-moisture ensiling decreased (P < .10) the insolubility of CP but did not otherwise seem to alter the chemical composition of grain sorghum relative to dry rolling . Starch was more available (P < .10), and DM was digested more rapidly and extensively (P < .10) in vitro, in steam-flaked sorghum followed by high-moisture sorghum . Based on these data, it seems that planting density primarily affected chemical composition of grain sorghum, whereas processing primarily affected CP insolubility and rate and extent of starch fermentation. Biosci Biotechnol Biochem, 2000 Jul, 64(7), 1337 - 44 Purification and characterization of acid-stable protopectinase produced by Aspergillus awamori in solid-state fermentation; Nagai M et al.; Aspergillus awamori IFO 4033 produced an acid-stable protopectinase in solid-state fermentation using wheat bran as the medium . The enzyme was purified to a homogeneous preparation with anion-exchange, hydrophobic, and size-exclusion chromatography . The enzyme was a monomeric protein of 52 kDa, by SDS-PAGE analysis, with an isoelectric point of pH 3.7 . The optimum pH for enzyme activity was 2.0, and it was most active at 50 degrees C (at pH 2.0) and was stable up to 50 degrees C (at pH 2.0) . The enzyme showed pectin-releasing activity toward protopectins from various origins, especially on lemon protopectin . An outstanding characteristic of the enzyme was its extreme stability in acidic conditions: the enzyme activity was not lost after incubating at pH 2.0 and 37 degrees C for 24 h. J Pharm Sci, 2000 Sep, 89(9), 1097 - 105 Determination of erythromycin and related substances in enteric-coated tablet formulations by reversed-phase liquid chromatography; Wardrop J et al.; An isocratic method for the identification and quantitation of erythromycin and related substances in enteric-coated tablet formulations using high-performance liquid chromatography (HPLC) with ultraviolet (UV) detection at 205 nm is described . A novel method for sample preparation using a molecular weight centrifuge filter to reduce the interferences observed from polymeric tablet coating material is also presented . Erythromycin HPLC assays are best run at high pH; therefore, various polymer columns were evaluated . The resulting HPLC method that was developed has several advantages over current pharmacopeial assay methods for enteric-coated erythromycin tablets . Comparative data from both methods for the same batch of EryTab tablets are presented . The method can also be applied to various other erythromycin formulations, including particle-coated tablets, erythromycin stearate tablets, and erythromycin ethylsuccinate suspensions and fermentation broths . A C18 Polymeric column is used with a mobile phase composition of 0.02 M potassium phosphate dibasic buffer (pH 9): acetonitrile (60:40) and flow rate of 1 mL/min . This method is more sensitive, specific, and rugged than the pharmacopeial method. J Exp Bot, 2000 Aug, 51(349), 1413 - 22 Anoxia tolerance in the aquatic monocot Potamogeton pectinatus absence of oxygen stimulates elongation in association with an unusually large pasteur effect; Summers JE et al.; Elongation by stems of overwintered tubers of Potamogeton pectinatus (L.) is strongly promoted over several days by oxygen-free conditions . Characteristics of the respiration underpinning this unusual response were examined . Anaerobic plants produced ethanol and CO(2) in approximately equimolar amounts, indicating that glycolysis coupled to alcoholic fermentation was the principal CO(2)-producing respiratory pathway . Rates of CO(2) evolution by aerobic and anaerobic whole plants (shoot and tuber) were similar, suggesting a rate of glycolysis three times that of aerobic plants, i.e . a strong Pasteur effect . In the shoot alone, anaerobic CO(2) production was twice the aerobic rate indicating a 6-fold increase in the rate of glycolysis in this tissue . Anoxic stems contained more sucrose at a stronger concentration than slower-growing aerobic stems or anaerobic leaves, demonstrating that sugar supply to the site of most rapid growth exceeded demand in the absence of oxygen . Concentrations of potentially toxic acetaldehyde in the external medium were small (approximately 0.2 mol m(-3)) during anoxia and on return to aerated conditions . Lactic acid was undetectable under anaerobic conditions and in vivo (31)P-NMR analysis of shoots revealed a cytoplasmic acidification of only </=0.2 pH units . In contrast, shoots of Pisum sativum, an anoxia-intolerant species, showed much stronger cytoplasmic acidification when transferred to oxygen-free conditions. Vopr Pitan, 2000, 69(1-2), 50 - 2 {Effects of mixture of fermented whey SGOL-1-40 ("Sgidolac") and sterilized milk on the course of experimental tuberculosis}; Lind RM et al.; The effect of enzymolic whey SGOL 1-40 ("Sgidolac") and sterilized milk mixture on experimental tuberculosis process with mice has been investigated . The mice of CBA line infected with tuberculosis (Type H37Rv) and been given this mixture (rate SGOL 1-40 to milk 1:5) per os immediately after the infection at the amount of 0.5 g/Kg body weight per day every day, perished on 42-nd day, meanwhile the mice that had received the mixture 3 weeks before the infection and all the period after it, died on 46-th day he mice in the control group (infected and untreated) died on the 38-th day . The positive treatment and prophylactic effect of the SGOL 1-40 and milk mixture on the tuberculosis process has been stated and morphologically proved. J Chromatogr B Biomed Sci Appl, 2000 Jun 23, 743(1-2), 5 - 12 Effect of biological suspensions on the position of the binodal curve in aqueous two-phase systems; Rito-Palomares M et al.; This study is concerned with the influence of biological suspension on the position of the binodal curve in aqueous two-phase systems (ATPSs) . Three different biological suspensions (i.e., disrupted yeast, E . coli homogenate and fermentation broth from Trichoderma harzianum) were selected and their impact upon ATPS performance was evaluated on the basis of changing volume ratio (Vr) and the position of the binodal curve of biological ATPSs (added with biomass) . Biological ATPSs with initial Vr greater than 1 and long (>40%, w/w) tie-line length (TLL), exhibited significant changes in Vr when compared with that from non-biological systems . Such behaviour was associated with the top phase biomass accumulation . It was shown that the addition of the biological suspensions used in this study to ATPSs caused the binodal curve to displace towards the origin, which was associated with the critical contribution of the bio-polymer (present in the systems) to the phase formation . The practical implementation of ATPSs for the purification of biological materials exploiting the information reported in this study is discussed. Res Rep Health Eff Inst, 1999 Oct, (89), i - ii, 1-117; discussion 119-33 Reproductive and offspring developmental effects following maternal inhalation exposure to methanol in nonhuman primates; Burbacher T et al.; INTRODUCTION: In an effort to improve air quality and decrease dependence on petroleum, the federal government, industry, and other groups have encouraged development of alternative fuels such as methanol to substitute for gasoline or diesel fuel . Methanol is also a candidate to provide the hydrogen for fuel cells, which are being developed for a variety of power sources (including motor vehicle engines) . Before people are exposed to increased concentrations of methanol, the potential health effects of such exposures require study . Methanol, a simple alcohol containing one carbon atom, occurs naturally in plants and animals and participates in human metabolism . People regularly consume low doses of methanol in fruits, vegetables, and fermented beverages as well as soft drinks and foods sweetened with aspartame (which breaks down to methanol in the gastrointestinal tract) . Despite its ubiquitous presence, methanol can be highly toxic if sufficient quantities are consumed . Ingestion of methanol (usually in the form of wood alcohol or tainted alcoholic beverages) can result in metabolic acidosis, blindness, and even death . Although the body has the capacity to metabolize the low doses of methanol to which people are regularly exposed, it cannot handle high doses because too much methanol overwhelms the body's ability to remove a toxic metabolite (formate) . When formate accumulates, methanol poisoning occurs . One factor that regulates the rate at which formate is removed is the liver level of a derivative of the vitamin folic acid . People who are deficient in folic acid (including 15% to 30% of pregnant women) may be particularly susceptible to the toxic effects of methanol . If methanol were to be widely adopted as a fuel, environmental exposures would increase through ingestion of contaminated drinking water, inhalation of vapors from evaporative and other emissions, and dermal contact . Current concentrations of methanol in ambient air are very low, 1 to 30 parts per billion (ppb) . If all motor vehicles in the United States were converted to 100% methanol fuel, methanol levels in ambient air are estimated to increase approximately 1,000-fold (to 1 to 10 ppm in cities) and in a worst-case situation could occasionally reach concentrations as high as 200 ppm in enclosed spaces (HEI 1987) . Inhaling these concentrations of methanol for short periods of time is not predicted to affect formate production and thus should not present a health risk . However, little is known about the consequences of long-term inhalation of methanol vapors, especially in susceptible populations of pregnant women and developing fetuses . HEI, therefore, developed a research program to address this information gap . APPROACH: Dr . Thomas Burbacher and colleagues of the University of Washington studied the effects of long-term exposure to methanol vapors on metabolism and reproduction in adult female monkeys (Macaca fascicularis) and developmental effects in their offspring, who were exposed prenatally to methanol . The investigators exposed adult female monkeys (11 to 12 animals/group) to one of four concentrations of methanol vapors (0, 200, 600, and 1,800 ppm) for 2.5 hours a day, seven days a week during the following periods: (1) before breeding, (2) during breeding, and (3) during pregnancy . They collected blood from the adults at regular intervals to monitor methanol levels (which served as a marker of internal dose) and formate concentrations . They also conducted pharmacokinetic studies to determine whether methanol disposition (which includes absorption, distribution, metabolism, and excretion) was altered as a result of repeated methanol exposures and to assess pregnancy-related changes . Because high doses of methanol damage the central nervous system, the infants (8 to 9 animals/group) were examined at regular intervals during the first nine months of life to assess their growth and neurobehavioral development . RESULTS: Exposure to methanol vapors did n Biotechnol Bioeng, 2000 Oct 5, 70(1), 65 - 71 Feasible boundaries of aqueous two-phase systems with NH(3) and CO(2) as recyclable volatile salts; van Berlo M et al.; Aqueous two-phase systems (ATPSs) have great potential for use in the downstream processing of fermentation products . A major drawback of these systems, limiting application in industrial practice up till now, is the consumption of large amounts of auxiliary materials such as polymers and salts . Making use of alternative auxiliaries can diminish this relatively large discharge . A possible approach is to make use of volatile salts induced by combinations of ammonia and carbon dioxide that can be recycled to the extraction system . As part of an ongoing research effort on ATPSs with volatile salts, this work aims at getting more information on the system boundaries or operating conditions of these systems in terms of phase behavior . The results show that the NH(3)/CO(2) ratio is an important parameter that has a large influence on the system boundaries . Both for systems with PEG 2000 and PEG 4000, this ratio has to be larger than about 1.75 to make a liquid-liquid phase separation possible . The most optimal ratio seems to be 2.0 for reasons of solution composition and absence of solid salt . J Bacteriol, 2000 Sep, 182(17), 4934 - 40 Effects of limited aeration and of the ArcAB system on intermediary pyruvate catabolism in Escherichia coli; Alexeeva S et al.; The capacity of Escherichia coli to adapt its catabolism to prevailing redox conditions resides mainly in three catabolic branch points involving (i) pyruvate formate-lyase (PFL) and the pyruvate dehydrogenase complex (PDHc), (ii) the exclusively fermentative enzymes and those of the Krebs cycle, and (iii) the alternative terminal cytochrome bd and cytochrome bo oxidases . A quantitative analysis of the relative catabolic fluxes through these pathways is presented for steady-state glucose-limited chemostat cultures with controlled oxygen availability ranging from full aerobiosis to complete anaerobiosis . Remarkably, PFL contributed significantly to the catabolic flux under microaerobic conditions and was found to be active simultaneously with PDHc and cytochrome bd oxidase-dependent respiration . The synthesis of PFL and cytochrome bd oxidase was found to be maximal in the lower microaerobic range but not in a delta ArcA mutant, and we conclude that the Arc system is more active with respect to regulation of these two positively regulated operons during microaerobiosis than during anaerobiosis. Int J Syst Evol Microbiol, 2000 Jul, 50 Pt 4, 1665 - 72 Use of conventional taxonomy, electrophoretic karyotyping and DNA-DNA hybridization for the classification of fermentative apiculate yeasts; Vaughan-Martini A et al.; A taxonomic study was conducted that considered strains of the genera Hanseniaspora/Kloeckera held in the Industrial Yeasts Collection (DBVPG) of the Dipartimento di Biologia Vegetale of the Universita di Perugia, Italy . Standard phenotypic as well as molecular criteria were considered in a effort to revisit the classification of these strains, some of which have been in the collection for about 50 years . Results of salient physiological tests showed that some of the DBVPG and type strains could not be identified by current taxonomic keys . Electrophoretic karyotypes were identical for some species, with the type strains of the seven accepted species showing only five distinct chromosomal patterns . DNA-DNA hybridization analyses, using a non-radioactive dot-blot technique, allowed for the distinction of taxa . The taxonomic implications of these results are discussed. J Exp Bot, 2000 Apr, 51(345), 785 - 96 Regulation of alcoholic fermentation in coleoptiles of two rice cultivars differing in tolerance to anoxia; Gibbs J et al.; To investigate regulation of anaerobic carbohydrate catabolism in anoxia-tolerant plant tissue, rate of alcoholic fermentation and maximum catalytic activities of four key enzymes were assessed in coleoptiles of two rice cultivars that differ in tolerance to anoxia . The enzymes were ATP-dependent phosphofructokinase (PFK), pyrophosphate-dependent phosphofructokinase (PFP), pyruvate decarboxylase (PDC), and alcohol dehydrogenase (ADH) . During anoxia, rates of coleoptile elongation and ethanol synthesis were faster in the more tolerant variety Calrose than in IR22 . Calrose coleoptiles, in contrast to IR22, also showed a sustained Pasteur effect, with the estimated rate of glycolysis during anoxia being 1.4-1.7-fold faster than that of aerobic coleoptiles . In Calrose after 5 d anoxia, maximum catalytic activities of crude enzyme extracts were (in mumol substrate g-1 fresh weight min.-1) 170-240 for ADH, 4-6 for PDC and PFP and 0.4-0.7 for PFK . During anoxia, activity per coleoptile of all four enzymes increased 3-5.5-fold, suggesting that PFK, and PFP, like PDC and ADH, are synthesised in anoxic rice coleoptiles . Enzyme activities, on a fresh weight basis, were lower in IR22 than in Calrose . In vivo activities of PDC and PFK in anoxic coleoptiles from both cultivars were calculated using in vitro activities, estimated substrate levels, cytoplasmic pH, and S0.5 (the substrate level at which 0.5Vmax is reached, without inferring Michaelis-Menten kinetics) . Data indicated that potential carbon flux through PFK, rather than through PDC, more closely approximated rates of alcoholic fermentation . That PFK is an important site of regulation was supported further for Calrose coleoptiles by a decrease in the concentration of its substrate pool (F-6-P + G-6-P) following the onset of anoxia . By contrast, in IR22, there was little evidence for control by PFK, consistent with recent evidence that suggests substrate supply limits alcoholic fermentation in this cultivar. Enzyme Microb Technol, 2000 Sep 1, 27(6), 376 - 389 Biocatalytic preparation of a chiral synthon for a vasopeptidase inhibitor: enzymatic conversion of N(2)- Patel RN, Banerjee A, Nanduri VB, Goldberg SL, Johnston RM, Hanson RL, McNamee CG, Brzozowski DB, Tully TP, Ko RY, LaPorte TL, Cazzulino DL, Swaminathan S, Chen C, Parker LW, Venit JJ. {4S-(4I,7I,10aJ)}1-Octahydro-5-oxo-4-{phenylmethoxy)carbonyl}amino}-7H-pyrido-{2,1-b} {1,3}thiazepine-7-carboxylic acid methyl ester (BMS-199541-01) is a key chiral intermediate for the synthesis of Omapatrilat (BMS-186716), a new vasopeptidease inhibitor under development . By using a selective enrichment culture technique we have isolated a strain of Sphingomonas paucimobilis SC 16113, which contains a novel L-lysine epsilon-aminotransferase . This enzyme catalyzed the oxidation of the epsilon-amino group of lysine in the dipeptide dimer N(2)-{N{phenyl-methoxy)-carbonyl} L-homocysteinyl} L-lysine)1,1-disulphide (BMS-201391-01) to produce BMS-199541-01 . The aminotransferase reaction required alpha-ketoglutarate as the amino acceptor . Glutamate formed during this reaction was recycled back to alpha-ketoglutarate by glutamate oxidase from Streptomyces noursei SC 6007 . Fermentation processes were developed for growth of S . paucimobilis SC 16113 and S . noursei SC 6007 for the production of L-lysine epsilon-amino transferase and glutamate oxidase, respectively . L-lysine epsilon-aminotransferase was purified to homogeneity and N-terminal and internal peptides sequences of the purified protein were determined . The mol wt of L-lysine epsilon-aminotransferase is 81 000 Da and subunit size is 40 000 Da . L-lysine epsilon-aminotransferase gene (lat gene) from S . paucimobilis SC 16113 was cloned and overexpressed in Escherichia coli . Glutamate oxidase was purified to homogeneity from S . noursei SC 6003 . The mol wt of glutamate oxidase is 125 000 Da and subunit size is 60 000 Da . The glutamate oxiadase gene from S . noursei SC 6003 was cloned and expressed in Streptomyces lividans . The biotransformation process was developed for the conversion of BMS-201391-01 to BMS-199541-01 by using L-lysine epsilon-aminotransferase expressed in E . coli . In the biotransformation process, for conversion of BMS-201391-01 (CBZ protecting group) to BMS-199541-01, a reaction yield of 65-70 M% was obtained depending upon reaction conditions used in the process . Phenylacetyl or phenoxyacetyl protected analogues of BMS-201391-01 also served as substrates for L-lysine epsilon-aminotransferase giving reaction yields of 70 M% for the corresponding BMS-199541-01 analogs . Two other dipeptides N-{N{(phenylmethoxy)carbonyl}-L-methionyl}-L-lysine (BMS-203528) and N,2-{S-acetyl-N-{(phenylmethoxy)carbonyl}-L-homocysteinyl}-L-lysine (BMS-204556) were also substrates for L-lysine epsilon-aminotransferase . N-alpha-protected (CBZ or BOC)-L-lysine were also oxidized by L-lysine epsilon-aminotransferase. Enzyme Microb Technol, 2000 Sep 1, 27(6), 362 - 370 Production of alcohol from raw wheat flour by Amyloglucosidase and Saccharomyces cerevisiae; Montesinos T et al.; Ethanol production, by a simultaneous saccharification and fermentation process from raw wheat flour, has been performed by Saccharomyces cerevisiae and a low level of amyloglucosidase enzyme . The fermentation time was about 60 h after a 6 h pre-saccharification, with an amyloglucosidase (AMG) level of 270 AGU . kg(-1) starch, but only 31 h with a simultaneous saccharification fermentation process (SSF) . When an AMG level of 540 AGU . kg(-1) starch was used, the time decreased to 21 h, giving an ethanol concentration of 67 g . l(-1) . Sugar composition of the wort after the liquefaction may be responsible of the difference between these two process . Maltose, a fermentable sugar, was produced in high concentration during the liquefaction, allowing a shorter process period, counteracting the effect of the slow starch hydrolysis at 35 degrees C (SSF temperature). Metab Eng, 1999 Oct, 1(4), 299 - 308 A maximum production strategy of lysine based on a simplified model derived from a metabolic reaction network; Shimizu H et al.; The aim of this study is to develop a strategy for maximum production of a target product with a simplified model derived from a metabolic reaction network through an example of lysine production . Based on the model, a search for the optimal specific growth rate profile was conducted among the available conditions of batch fermentation based on the derived model, when the total fermentation time was fixed . The optimal specific growth rate was obtained as a boundary control: initially, the specific growth rate was maintained at a maximum value and was subsequently switched to a critical value giving the maximum specific production rate . To make the specific growth rate follow this optimal profile as accurately as possible in batch mode, first, an appropriate initial concentration of leucine was employed in the experiment . Second, the feeding strategy of leucine was further studied . The specific growth rate profile with feeding was closer to the optimal one and the amount of lysine produced at the final stage of fermentation was increased about twofold, compared to that in the batch fermentation . Finally, the strategy was summarized as an algorithm for general use of this method. J Mol Microbiol Biotechnol, 2000 Jan, 2(1), 27 - 32 The economics of acetone-butanol fermentation: theoretical and market considerations; Gapes JR; Acetone-butanol (AB) fermentation was once run commercially in many countries until these chemicals could be made more cheaply from fossil oil sources . Research into the revitalisation of the process has shown that the process could once again be run economically in niche markets if run in a relatively small industrial scale processing low-grade agricultural products . The following analysis is intended to help identify suitable niche markets. J Mol Microbiol Biotechnol, 2000 Jan, 2(1), 15 - 20 The acetone-butanol fermentation in pilot plant and pre-industrial scale; Nimcevic D et al.; A summary of literature data concerning pilot or preindustrial scale trials of the acetone-butanol fermentation throughout its history is given . The recent pilot plant trials in Austria are also described for the first time . Some aspects of the current development of the acetone-butanol fermentation in general, especially from a technical point of view are also discussed. J Mol Microbiol Biotechnol, 2000 Jan, 2(1), 5 - 8 The history of the acetone-butanol project in Austria; Gapes JR; The acetone-butanol fermentation and the closely related 2-propanol-butanol fermentation are of interest to Europe in particular for environmental and socioeconomic reasons, but its economic and technical feasibility must be proven before reestablishment as a commercial proposition . In particular the reestablishment of a new, fledgling fermentation industry selling into markets presently serviced by the mature, firmly established and highly capitalised petrochemical industry will require a significant driving force or else commercial users, who frequently have long-term supply contracts, will remain with known and proven suppliers . Hence the present state-of-the-art of the acetone-butanol fermentation is best described as technically and economically difficult but possible in niche markets . The most likely future is for decentral fermentation facilities processing locally made substrates and selling into niche markets. J Biotechnol, 2000 Jul 28, 81(1), 27 - 34 Effect of nitrogen source and nitrogen concentration on the production of pyruvate by Torulopsis glabrata; Li Y et al.; The effect of nitrogen sources including yeast extract, peptone, soybean hydrolyzate and some inorganic nitrogen sources, as well as the nitrogen concentration on the fermentative production of pyruvate by Torulopsis glabrata WSH-IP12 was investigated . The addition of yeast extract greatly inhibited pyruvate accumulation, while peptone was shown to be the most favorable nitrogen source . In flask culture, 15 g l(-1) peptone was needed to consume 80 g l(-1) glucose with 23.4 g l(-1)of pyruvate accumulated . Pyruvate production was markedly dependent on the ratio of carbon to nitrogen (C:N), its production was improved by increasing the concentration of glucose and peptone proportionally and reduced by exclusively increasing the glucose concentration . In a glucose fed-batch culture, cell growth and pyruvate production slowed after 28 h . However, cell growth and pyruvate production recovered after further nitrogen, in the form of peptone and ammonium sulfate, was added to the culture . A final concentration of pyruvate of 54.5 g l(-1) was achieved at 64 h (yield to glucose consumed of 0.471 g g(-l)) . By using aqueous ammonia instead of potassium hydroxide for pH control, 57.3 g l(-1) pyruvate with a yield of 0.498 g g(-1) was produced by 55 h . This result further indicates that nitrogen level plays an important role in the production of pyruvate. Plant Sci, 2000 Jul 28, 156(2), 151 - 158 Fermentative metabolism in grape berries: isolation and characterization of pyruvate decarboxylase cDNA and analysis of its expression throughout berry development; Or E et al.; The involvement of pyruvate decarboxylase (PDC) in the control of alcohol production during ripening of fruit tissues under aerobic conditions has been only partially studied . Enzymological studies showed a significant increase in PDC activity during the ripening of oranges and pears, concurrently with the induction of ethanol production . In tomato, on the other hand, the induction of ethanol production and ADH gene expression after the onset of ripening was not accompanied by induction of PDC activity . The isolation of PDC cDNA from fruits has not yet been reported, nor has its expression pattern during fruit development . We report here the isolation of a cDNA clone encoding for a grape PDC and the characterization of its expression throughout berry development . The pattern of PDC gene expression throughout berry development, combined with earlier findings on constitutive PDC activity in the berry, may suggest that PDC is not the limiting factor for the production of ethanol in the berry, which is induced only after the onset of berry ripening . Alternatively, the induction of ADH gene expression, which occurs only after the onset of ripening in both tomatoes and grape berries, may serve as a regulator of ethanol production in response to a ripening-related cue. Metab Eng, 2000 Jan, 2(1), 69 - 77 Optimization of ethanol production in Saccharomyces cerevisiae by metabolic engineering of the ammonium assimilation; Nissen TL et al.; Ethanol is still one of the most important products originating from the biotechnological industry with respect to both value and amount . In addition to ethanol, a number of byproducts are formed during an anaerobic fermentation of Saccharomyces cerevisiae . One of the most important of these compounds, glycerol, is produced by yeast to reoxidize NADH, formed in synthesis of biomass and secondary fermentation products, to NAD+ . The purpose of this study was to evaluate whether a reduced formation of surplus NADH and an increased consumption of ATP in biosynthesis would result in a decreased glycerol yield and an increased ethanol yield in anaerobic cultivations of S . cerevisiae . A yeast strain was constructed in which GLN1, encoding glutamine synthetase, and GLT1, encoding glutamate synthase, were overexpressed, and GDH1, encoding the NADPH-dependent glutamate dehydrogenase, was deleted . Hereby the normal NADPH-consuming synthesis of glutamate from ammonium and 2-oxoglutarate was substituted by a new pathway in which ATP and NADH were consumed . The resulting strain TN19 (gdh1-A1 PGK1p-GLT1 PGK1p-GLN1) had a 10% higher ethanol yield and a 38% lower glycerol yield compared to the wild type in anaerobic batch fermentations . The maximum specific growth rate of strain TN19 was slightly lower than the wild-type value, but earlier results suggest that this can be circumvented by increasing the specific activities of Gln1p and Glt1p even more . Thus, the results verify the proposed concept of increasing the ethanol yield in S . cerevisiae by metabolic engineering of pathways involved in biomass synthesis. Metab Eng, 1999 Apr, 1(2), 141 - 52 Redistribution of metabolic fluxes in Escherichia coli with fermentative lactate dehydrogenase overexpression and deletion; Yang YT et al.; Under anaerobic conditions, competition for pyruvate between the branch point enzymes pyruvate formate lyase (PFL, Km = 2 mM) and fermentative lactate dehydrogenase (LDH, Km = 7.2 mM) determines the partition of carbon flux . Two Escherichia coli mutant strains, one deficient in ackA, pta, and ldhA and the other overexpressing LDH, were constructed to systematically analyze the effects of these perturbations in the existing pathways on the redistribution of carbon fluxes . Deletion of the lactate and acetate synthesis pathways was detrimental to cell growth . Carbon flux is forced through ethanol and formate production pathways, resulting in a concomitant increase in those fluxes . In addition, overexpression of LDH simultaneously increases the common flux as well as the flux to the competing acetyl-CoA branch . Overexpression of lactate dehydrogenase (ldhA) in the parent strain increases the lactate synthesis rate from 0.19 to 0.40 mmol/g-biomass-h when the LDH activities increases from 1.3 to 15.3 units . Even an increase of more than 10 times in the LDH activity fails to divert a large fraction of the carbon flux to lactate; the majority of the flux still channels through the acetyl-CoA branch . Overexpression of LDH in the parent strain simultaneously increases the common flux as well as the flux through the acetyl-CoA branch . Subsequently, the flux amplification factors (or deviation indices which can be related to the flux control coefficients) are positive for all three fluxes occurring at the pyruvate node. Chin J Biotechnol, 1999, 15(3), 165 - 70 Cultivation of encapsulated yeast cells in NaCS-PDMDAAC polyelectrolyte complexes; Zhang H et al.; The cultivation of encapsulated S . cerevisiate and C . utilis in NaCS-PDMDAAC Polyelectrolyte Complexes was studied . The results showed that these two kinds of encapsulated microorganisms showed the same growing properties as in their free cell cultures, and thus NaCS-PDMDAAC microcapsules were suitable for the encapsulation of biological substances . The encapsulated S . cerevisiate cells were fermented sequentially for 16 batches . The highest cell density in the capsules reached 2.64 x 10(10) cells/mL and ethanol concentration reached 47.0 g/L . The encapsulated C . utilis produced the same amount of GSH as the free cell culture. Biotechnol Prog, 2000 Jul-Aug, 16(4), 661 - 7 Selective flocculation and precipitation for the improvement of virus-like particle recovery from yeast homogenate; Tsoka S et al.; The purification of an intracellular product from a complex mixture of contaminants after cell disruption is a common problem in processes downstream of fermentation systems . This is particularly challenging for the recovery of particulate (80 nm in diameter) multimeric protein products, named virus-like particles (VLPs), from cell debris and other intracellular components . Selective flocculation for debris removal followed by selective precipitation of the target protein can be used as a preclarification step to aid purification . In this paper, selective borax flocculation of cell debris in yeast homogenate, followed by selective poly(ethylene glycol) precipitation of VLPs are defined with a view to demonstrating their potential in aiding the initial clarification stages of the purification sequence . The translation from laboratory scale to pilot scale operation is addressed, demonstrating the challenge of scale-up of solid-liquid separation stages for biological particle processing. Biotechnol Prog, 2000 Jul-Aug, 16(4), 571 - 6 A recombinant lipoprotein antigen against Lyme disease expressed in E . coli: fermentor operating strategies for improved yield; Madurawe RD et al.; Decorin-binding lipoprotein, lpp-DBP, a bacterial surface adhesin, shows promise as a vaccine against Lyme disease . It is expressed in recombinant E . coli as an undesirable 20.5 KDa apoprotein that is subsequently lipidated in vivo to the desired 22 KDa lpp-DBP form . This study defines fermentation conditions for maximizing lpp-DBP yield . Super broth medium, a low post-induction temperature (30 degrees C), and a glucose feed based on dissolved oxygen resulted in high lpp-DBP yield and minimized apoprotein formation . Since cells lysed within 2-3 h after induction, the cell yield was maximized by growing cells to high cell density prior to induction . Compared to a glucose feed based on maintaining a constant fermentor glucose concentration (Glucose-Stat), feeding based on maintaining a constant dissolved oxygen level (DO-Stat) improved yields . Also, a dissolved oxygen level of 60% (air saturation) was best, as no product degradation was detected by Western blotting and SDS-PAGE . Acetic acid levels under both modes of glucose feed were sufficiently low, and no adverse growth effects were observed. Biotechnol Prog, 2000 Jul-Aug, 16(4), 553 - 6 Precursor-directed biosynthesis of 6-deoxyerythronolide B analogs in Streptomyces coelicolor: understanding precursor effects; Leaf T et al.; A fermentation process employing precursor-directed biosynthesis is being developed for the manufacture of 6-deoxyerythronolide B (6-dEB) analogues . Through a plasmid-based system in Streptomyces coelicolor, 6-dEB synthesis is catalyzed by 6-dEB synthase (DEBS) . 6-dEB synthesis is abolished by inactivation of the ketosynthase (KS) 1 domain of DEBS but can be restored by providing synthetic activated diketides . Because of its inherent catalytic flexibility, the KS1-deficient DEBS is capable of utilizing unnatural diketides to form various 13-substituted 6-dEBs . Here we characterize process variables associated with diketide feeding in shake-flask experiments . 13-R-6-dEB production was found to depend strongly on diketide feed concentrations, on the growth phase of cultures at feeding time, and on the R-group present in the diketide moiety . In all cases a major portion of the fed diketides was degraded by the cells. Biotechnol Prog, 2000 Jul-Aug, 16(4), 541 - 7 Dry-grind process for fuel ethanol by continuous fermentation and stripping; Taylor F et al.; Conversion of a high-solids saccharified corn mash to ethanol by continuous fermentation and stripping was successfully demonstrated in a pilot plant consuming 25 kg of corn per day . A mathematical model based on previous pilot plant results accurately predicts the specific growth rate obtained from these latest results . This model was incorporated into a simulation of a complete dry-grind corn-to-ethanol plant, and the cost of ethanol production was compared with that of a conventional process . The results indicate a savings of $0.03 per gallon of ethanol produced by the stripping process . The savings with stripping result from the capacity to ferment a more concentrated corn mash so there is less water to remove downstream. Food Addit Contam, 2000 Jun, 17(6), 469 - 75 Determination of ethyl carbamate in some fermented Korean foods and beverages; Kim YK et al.; Ethyl carbamate has been associated with cancer for several decades . It is mainly found in fermented foods and beverages . In view of the importance of fermented foods in the Korean diet and the significant level of ethyl carbamate expected, we determined ethyl carbamate concentrations in some of the staple food items and estimated the daily intake for the Korean population . Ethyl carbamate in commercial samples of kimchi, soy sauce, vinegar, soybean paste, and alcoholic beverages were determined by gas chromatography-mass spectrometry/selective ion monitoring (GC-MS/SIM) . Homemade soy sauce and kimchi were also analysed . The maximum ethyl carbamate concentrations observed were 73 micrograms/kg in soy sauce, 7.9 micrograms/kg in soybean paste, 2.5 micrograms/l in vinegar, 16.2 micrograms/kg in kimchi and 15.4 mu/l in Korean traditional alcoholic beverages . Combining these values with the average daily food intake data, we estimated that the maximum daily exposure of Korean population to ethyl carbamate is 2.8 micrograms/day, which is not a negligible amount considering the 'virtually safe dose' derived by animal experiment ranges between 1.2 and 4.8 micrograms/day . It would be desirable to closely monitor ethyl carbamate levels in Korean foods and to find ways to reduce the daily intake. Rev Latinoam Microbiol, 1998 Jan-Jun, 40(1-2), 109 - 19 {Biosynthesis of congeners during alcohol fermentation}; Santillan-Valverde MC et al.; The flavor of alcoholic beverages is a consequence of a complex mixture of many compounds, including small concentrations of some volatile metabolites known as congeners, which are produced by the yeast during the fermentation . The more important compounds are those that can be found in all the alcoholic beverages in different concentrations, and they can be grouped on the following chemical species: higher alcohols, esters, and carboniles . In the current paper the biochemical pathways that produce these compounds from the raw materials are reviewed . Research done in this field has led to a more complete knowledge concerning to organoleptic profiles of alcoholic beverages and to a better control for the production of the final product. Syst Appl Microbiol, 2000 Jun, 23(2), 300 - 3 Expression levels and patterns of glycolytic yeast genes during wine fermentation; Puig S et al.; Promoters from glycolytic genes are widely used for gene overexpression in the yeast Saccharomyces cerevisiae . Wine strains are not an exception, and genes of enological interest have been expressed in this way . However, the transcriptional pattern of glycolytic genes has never been studied during wine fermentation . In this work we describe the levels and expression patterns of glycolytic genes for a wine yeast strain during the alcoholic fermentation of three different musts . Results show similar transcriptional patterns for all genes studied: maximal levels of mRNA at the exponential growth stage, and a gradual decrease during the stationary phase, in accordance with the fermentation rates . The glyceraldehyde 3-phosphate dehydrogenase genes reach the highest transcriptional levels during wine fermentation, similarly as previously described for laboratory strains and conditions. Syst Appl Microbiol, 2000 Jun, 23(2), 165 - 73 The role of cold-shock proteins in low-temperature adaptation of food-related bacteria; Wouters JA et al.; There is a considerable interest in the cold adaptation of food-related bacteria, including starter cultures for industrial food fermentations, food spoilage bacteria and food-borne pathogens . Mechanisms that permit low-temperature growth involve cellular modifications for maintaining membrane fluidity, the uptake or synthesis of compatible solutes, the maintenance of the structural integrity of macromolecules and macromolecule assemblies, such as ribosomes and other components that affect gene expression . A specific cold response that is shared by nearly all food-related bacteria is the induction of the synthesis so-called cold-shock proteins (CSPs), which are small (7 kDa) proteins that are involved in mRNA folding, protein synthesis and/or freeze protection . In addition, CSPs are able to bind RNA and it is believed that these proteins act as RNA chaperones, thereby reducing the increased secondary folding of RNA at low temperatures . In this review established and novel aspects concerning the structure, function and control of these CSPs are discussed . A model for bacterial cold adaptation, with a central role for ribosomal functioning, and possible mechanisms for low-temperature sensing are discussed. Plant J, 2000 Jul, 23(1), 115 - 22 Functional identification of an Arabidopsis snf4 ortholog by screening for heterologous multicopy suppressors of snf4 deficiency in yeast; Kleinow T et al.; Yeast Snf4 is a prototype of activating gamma-subunits of conserved Snf1/AMPK-related protein kinases (SnRKs) controlling glucose and stress signaling in eukaryotes . The catalytic subunits of Arabidopsis SnRKs, AKIN10 and AKIN11, interact with Snf4 and suppress the snf1 and snf4 mutations in yeast . By expression of an Arabidopsis cDNA library in yeast, heterologous multicopy snf4 suppressors were isolated . In addition to AKIN10 and AKIN11, the deficiency of yeast snf4 mutant to grown on non-fermentable carbon source was suppressed by Arabidopsis Myb30, CAAT-binding factor Hap3b, casein kinase I, zinc-finger factors AZF2 and ZAT10, as well as orthologs of hexose/UDP-hexose transporters, calmodulin, SMC1-cohesin and Snf4 . Here we describe the characterization of AtSNF4, a functional Arabidopsis Snf4 ortholog, that interacts with yeast Snf1 and specifically binds to the C-terminal regulatory domain of Arabidopsis SnRKs AKIN10 and AKIN11. Z Naturforsch {C}, 2000 May-Jun, 55(5-6), 341 - 6 Oxidative metabolism of ambrox and sclareolide by Botrytis cinerea; Farooq A et al.; Ambrox (1), a perfumery diterpene, was oxidatively metabolised by a plant pathogenic fungus Botrytis cinerea in a xenobiotic fashion to afford a major product, i.e., 1beta-hydroxy-8-epiambrox (13) (60%) along with three minor metabolites 3beta-hydroxyambrox (2), sclareolide (5) and 3beta-hydroxysclareolide (7) . Sclareolide (5), a cytotoxic diterpenoidal lactone was fermented with the same fungus to yield 3beta-hydroxysclareolide (7) (59%) as a major metabolite together with two minor metabolites characterised as 1-ketosclareolide (15), and 3beta,14-dihydroxysclareolide (16). Anticancer Res, 2000 May-Jun, 20(3B), 2245 - 8 Population thiamine status and varying cancer rates between western, Asian and African countries; Boros LG; The role of food supplements in the form of vitamins has not been extensively investigated in relation to varying cancer rates between populations of different geographical regions . New data indicate that thiamine (vitamin B1), a common food supplement in Western food products, is directly involved in nucleic acid ribose synthesis of tumor cells in its biologically activated form through the non-oxidative transketolase catalyzed pentose cycle reaction . Whether thiamine plays a role in increased cancer rates in the Western World by enhancing tumor cell proliferation, while increased consumption of thiaminase rich food limiting thiamine availability protects against common malignancies in Asia and Africa has not been evaluated . In the Western World, thiamine is a popular vitamin supplement in the form of tablets and it is also added to basic food items such as milled flour, cereals, peanut butter, refreshment drinks and pastas . On the contrary, thiaminase, the natural thiamine-degrading enzyme, is abundantly present in raw and fermented fish, certain vegetables and roasted insects consumed primarily in Africa and Asia . Excess thiamine supplementation in common food products may contribute to the increased cancer rates of the Western World. Fertil Steril, 2000 Aug, 74(2), 203 - 12 Use of fibrinolytic agents in the prevention of postoperative adhesion formation; Hellebrekers BW et al.; OBJECTIVE: To review the events leading to the formation of adhesions, to describe the development of fibrinolytic agents, to review more than a century of research on the use of fibrinolytic agents in adhesion prevention, and to look at future aspects of adhesion prevention . RESULTS: A better understanding of the pathogenesis of adhesion formation has resulted in the use of fibrinolytic agents in their prevention . Fibrinolytic agents promote fibrinolytic activity during the early period after peritoneal trauma during which an increased formation of fibrin is seen in combination with a deficiency of endogenous fibrinolytic activity . Initially, chemical attacks on fibrin (fibrolysin and hypertonic glucose), foreign digestive ferments (pepsin, trypsin, and papain), and stimulation of intraperitoneal leukocytosis (amniotic fluid) were used . Development of new thrombolytic agents was soon followed by experiments in animal adhesion models and clinical studies to examine their antiadhesion properties . Plasmin preparations (plasmin, actase, and fibrinolysin) and plasmin activators (streptokinase, urokinase, and tissue-type plasminogen activator) were found to be efficacious in preventing adhesion formation in the greater part of reviewed animal and clinical studies . CONCLUSION(S): From the current literature, it can be concluded that postoperative intraperitoneal administration of thrombolytic agents can significantly decrease adhesion formation . Given the large number of experimental studies in animals, future studies should focus on the clinical use of fibrinolytic agents in the prevention of postsurgical adhesion formation. Biochem J, 2000 Aug 15, 350 Pt 1, 261 - 8 Expression of escherichia coli otsA in a Saccharomyces cerevisiae tps1 mutant restores trehalose 6-phosphate levels and partly restores growth and fermentation with glucose and control of glucose influx into glycolysis; Bonini BM et al.; The TPS1 gene, encoding trehalose-6-phosphate synthase (TPS), exerts an essential control on the influx of glucose into glycolysis in the yeast Saccharomyces cerevisiae . The deletion of TPS1 causes an inability to grow on glucose because of a hyperaccumulation of sugar phosphates and depletion of ATP and phosphate . We show that expression of the Escherichia coli homologue, otsA, in a yeast tps1 mutant results in high TPS activity . Although the trehalose 6-phosphate (Tre6P) level during exponential growth on glucose was at least as high as in a wild-type yeast strain, growth on glucose was only partly restored and the lag phase was much longer . Measurement of the glycolytic metabolites immediately after the addition of glucose showed that in spite of a normal Tre6P accumulation there was still a partial hyperaccumulation of sugar phosphates . Strong elevation of the Tre6P level by the additional deletion of the TPS2 gene, which encodes Tre6P phosphatase, was not able to cause a strong decrease in the sugar phosphate levels in comparison with the wild-type strain . In addition, in chemostat experiments the short-term response to a glucose pulse was delayed, but normal metabolism was regained over a longer period . These results show that Tre6P synthesis from a heterologous TPS enzyme can to some extent restore the control of glucose influx into glycolysis and growth on glucose in yeast . However, they also indicate that the yeast TPS enzyme, as opposed to the E . coli otsA gene product, is able to increase the efficiency of the Tre6P control on glucose influx into yeast glycolysis. Membr Cell Biol, 2000, 13(4), 511 - 26 Relationship between formate hydrogen lyase and proton-potassium pump under heterolactic fermentation in Escherichia coli: functional multienzyme associations in the cell membrane; Trchounian AA et al.; Anaerobically grown glucose-fermenting E . coli cells produce molecular hydrogen, acidify the medium and uptake potassium ions . It was shown that the H2 release and the proton-potassium exchange with the fixed (2H+/K+) stoichiometry of the initial DCC-sensitive fluxes were lost in mutants with the deleted fdhF gene or the hycA-H operon responsible for the biosynthesis of formate dehydrogenase H (FDH,H) or hydrogenase 3 (H3), respectively, which are the main components of the formate hydrogen lyase FHL(H) . However, both processes occurred in mutants with the deleted hycE, hycF or hycG genes encoding the major and minor components of H3, respectively . The K+ uptake was sensitive to the osmotic shock resulting from glucose addition to the medium and decreased significantly in the presence of valinomycin . The H2 release and the 2H+/K+ exchange were absent in the mutant with the deleted hycB gene encoding the corresponding minor component of H3 . This mutant acidified the medium and uptook K+ with Km typical for TrkA, but the stoichiometry of the DCC-inhibited fluxes was variable, and the K+ gradient between the cytoplasm and the medium in this mutant was lower than in the mutants lacking other minor components of H3 . The results obtained suggest that the hycB gene product, FdhF and HycE, form probably the FHL(H) complex that directly interacts with the H+-ATPase complex F0F1 and the TrkA(H) system of K+ uptake . Such a multienzyme association is responsible for the H2 production and 2H+/K+ exchange . The major and other minor components of H3 have probably no direct role in the H2 production and 2H+/K+ exchange . H2 production by precursor's or hycE mutant's protoplasts treated with toluene was shown to occur upon addition of the thiol reagent dithiothreitol to the medium containing ATP, potassium ions, NAD+, and NADH . H2 production was inhibited by DCC . The quantity of available thiol groups in membrane vesicles of the precursor or the hycE, hycF or hycG mutants, in which the H2 production and 2H+/K+ exchange were observed, was larger than in other mutants . The number of SH groups decreased in the presence of DCC . These results indicate a significance of the thiol groups for the function of the proposed association. Appl Environ Microbiol, 2000 Aug, 66(8), 3151 - 9 Engineering of the pyruvate dehydrogenase bypass in Saccharomyces cerevisiae: role of the cytosolic Mg(2+) and mitochondrial K(+) acetaldehyde dehydrogenases Ald6p and Ald4p in acetate formation during alcoholic fermentation; Remize F et al.; Acetic acid plays a crucial role in the organoleptic balance of many fermented products . We have investigated the factors controlling the production of acetate by Saccharomyces cerevisiae during alcoholic fermentation by metabolic engineering of the enzymatic steps involved in its formation and its utilization . The impact of reduced pyruvate decarboxylase (PDC), limited acetaldehyde dehydrogenase (ACDH), or increased acetoacetyl coenzyme A synthetase (ACS) levels in a strain derived from a wine yeast strain was studied during alcoholic fermentation . In the strain with the PDC1 gene deleted exhibiting 25% of the PDC activity of the wild type, no significant differences were observed in the acetate yield or in the amounts of secondary metabolites formed . A strain overexpressing ACS2 and displaying a four- to sevenfold increase in ACS activity did not produce reduced acetate levels . In contrast, strains with one or two disrupted copies of ALD6, encoding the cytosolic Mg(2+)-activated NADP-dependent ACDH and exhibiting 60 and 30% of wild-type ACDH activity, showed a substantial decrease in acetate yield (the acetate production was 75 and 40% of wild-type production, respectively) . This decrease was associated with a rerouting of carbon flux towards the formation of glycerol, succinate, and butanediol . The deletion of ALD4, encoding the mitochondrial K(+)-activated NAD(P)-linked ACDH, had no effect on the amount of acetate formed . In contrast, a strain lacking both Ald6p and Ald4p exhibited a long delay in growth and acetate production, suggesting that Ald4p can partially replace the Ald6p isoform . Moreover, the ald6 ald4 double mutant was still able to ferment large amounts of sugar and to produce acetate, suggesting the contribution of another member(s) of the ALD family. Appl Microbiol Biotechnol, 2000 Jun, 53(6), 646 - 9 Economic considerations in the production of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) by bacterial fermentation; Choi J et al.; The process for the production of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) {P(3HB/V)} by bacterial fermentation and its recovery was analysed . The effects of various factors such as P(3HB/V) content, P(3HB/V) productivity, P(3HB/V) yield and 3-hydroxyvalerate (3HV) fraction in P(3HB/V) on the production cost of P(3HB/V) were examined . The increase in the 3HV yield on a carbon source did not significantly decrease the production cost when the 3HV fraction was 10 mol%, because the cost of the carbon substrate for 3HV was relatively small in terms of the total cost . However, at a 3HV fraction of 30 mol%, the 3HV yield on a carbon source had a significant effect on the total P(3HB/V) production cost . The production cost of P(3HB/V) increased linearly with the increase in the 3HV fraction in P(3HB/V). Farmaco, 2000 Mar, 55(3), 165 - 7 Recombinant production of PIGF-1 and its activity in animal models; Maglione D et al.; In this paper we review current knowledge on placenta growth factor (PIGF) and summarise our data on its recombinant production in bacteria and its activity . PIGF and vascular endothelial growth factor (VEGF) are both angiogenic factors belonging to the platelet-derived growth factor (PDGF) family . PIGF is a dimeric glycoprotein which shares a number of biochemical and functional features with VEGF . The aminoacidic similarity between the two factors is high (about 50%) in the PDGF-like domain . By alternative splicing of the PIGF mRNA, three forms of PIGF protein are generated which are named PIGF-1, PIGF-2 and PIGF-3 . We have focused our attention on form 1 of human PIGF (PIGF-1) . A large quantity of active recombinant PIGF-1 has been obtained using a bacterial expression system . By optimising the fermentation and purification it was possible to produce about 140 mg/l of culture of active PIGF-1, which is potentially suitable for a pharmaceutical use . The angiogenic activity of two different batches of bacteria-derived PIGF-1 obtained in our laboratory was demonstrated in chick chorionallantoic membrane assays . Finally, in preliminary studies we have shown that bacteria-derived PIGF-1 has a protective effect against myocardial lesions induced by isoprenaline in rat and rabbit. J Nutr, 2000 Aug, 130(8), 1991 - 5 Fermentation of resistant rice starch produces propionate reducing serum and hepatic cholesterol in rats; Cheng HH et al.; This study was designed to investigate the effects of different proportions of rice starch and cornstarch on lipid metabolism in rats fed high dietary cholesterol . Male Wistar rats were fed a 10 g/100 g fat diet containing 1 g/100 g cholesterol with 0 (control diet), 15, 30, 45 or 63 g/100 g rice starch with an enzyme resistant starch concentration of 1.26, 1.39, 1.52, 1.65 or 1.80 g/100 g, respectively, for 4 wk . Groups fed diets with < 63 g/100 g rice starch were supplemented with cornstarch to 63 g/100 g . The two kinds of starch had different structures as seen using scanning electron microscopy (SEM) . The rice starch was an aggregation (n = 20-60) of smaller granules (3-8 microm in diameter), whereas the cornstarch was composed of larger (5-15 microm in diameter), single granules . The compound rice starch (0.99 kg/L) was larger in size and denser in structure than cornstarch (0.63 kg/L) . Serum total cholesterol concentrations in rats fed both the 45 and 63 g/100 g rice starch diets were significantly lower than in all other groups (P < 0.05) . The serum propionate concentration in the rats fed 63 g/100 g rice starch diets was significantly higher than that of other groups . Hepatic triglyceride and total cholesterol concentrations in rats fed 63 g/100 g rice starch diets were significantly lower than in the control group . These results suggest that, because the compound rice starch was an aggregation of smaller granules, larger in size and denser in structure than cornstarch, it was digested more slowly and altered lipid metabolism . Resistant rice starch may be fermented to produce propionate, which reduces serum and hepatic cholesterol. J Nutr, 2000 Aug, 130(8), 1887 - 93 Isoflavone aglycone-rich extract without soy protein attenuates atherosclerosis development in cholesterol-fed rabbits; Yamakoshi J et al.; The antiatherogenic effect of soy protein with intact isoflavones is well established, but the effects of isoflavones without soy protein have not been determined . We investigated the antiatherogenic effect of an isoflavone aglycone-rich extract (containing 429.4 mg/g isoflavone aglycones) without soy protein from fermented soy in cholesterol-fed rabbits . We fed 12-wk-old New Zealand white male rabbits diets containing 1 g/100 g cholesterol with 0, 0.33 or 1 g/100 g isoflavone aglycones for 8 wk . We also fed the rabbits a diet containing 1 g/100 g cholesterol with 1.09 g/100 g soy saponin-rich extract, a component other than isoflavone aglycones in the isoflavone aglycone-rich extract . Controls did not consume cholesterol, isoflavone aglycones or saponins . The isoflavone aglycone- and saponin-rich extracts did not affect the serum lipid profile of cholesterol-fed rabbits . The serum concentration of daidzein in its conjugated form was significantly higher in the high isoflavone group than in the low isoflavone group . The level of cholesteryl ester hydroperoxide (ChE-OOH) induced by CuSO(4) in plasma in the high isoflavone group was significantly less than that in the cholesterol group, and the ChE-OOH levels of LDL in the low and high isoflavone groups were significantly less than those in the cholesterol group . The ChE-OOH levels in plasma and LDL in the saponin group did not differ from the cholesterol group . In the aortic arch, the cholesterol concentration was significantly lower in the high isoflavone group, and malondialdehyde concentration was significantly lower in the low and high isoflavone groups compared with the cholesterol group; however these concentrations in the saponin group did not differ from those in the cholesterol group . The atherosclerotic lesion area of the aortic arch was significantly lower in the isoflavone groups (26.3% lower in the low isoflavone group and 36.9% lower in the high isoflavone group) than in the cholesterol group . The lesion areas were not different in the soy saponin and cholesterol groups . Immunohistochemical analysis revealed fewer oxidized LDL-positive macrophage-derived foam cells in atherosclerotic lesions in the aortic arch of isoflavone groups compared with that of the cholesterol group . These results suggest that the antioxidative action of isoflavones and their antioxidative metabolites inhibit the oxidation of LDL, thereby exerting an antiatherosclerotic effect. J Biol Chem, 2000 Oct 27, 275(43), 33869 - 75 Evolution of the adhE gene product of Escherichia coli from a functional reductase to a dehydrogenase . Genetic and biochemical studies of the mutant proteins; Membrillo-Hernandez J et al.; The multifunctional AdhE protein of Escherichia coli (encoded by the adhE gene) physiologically catalyzes the sequential reduction of acetyl-CoA to acetaldehyde and then to ethanol under fermentative conditions . The NH(2)-terminal region of the AdhE protein is highly homologous to aldehyde:NAD(+) oxidoreductases, whereas the COOH-terminal region is homologous to a family of Fe(2+)-dependent ethanol:NAD(+) oxidoreductases . This fusion protein also functions as a pyruvate formate lyase deactivase . E . coli cannot grow aerobically on ethanol as the sole carbon and energy source because of inadequate rate of adhE transcription and the vulnerability of the AdhE protein to metal-catalyzed oxidation . In this study, we characterized 16 independent two-step mutants with acquired and improved aerobic growth ability on ethanol . The AdhE proteins in these mutants catalyzed the sequential oxidation of ethanol to acetaldehyde and to acetyl-CoA . All first stage mutants grew on ethanol with a doubling time of about 240 min . Sequence analysis of a randomly chosen mutant revealed an Ala-267 --> Thr substitution in the acetaldehyde:NAD(+) oxidoreductase domain of AdhE . All second stage mutants grew on ethanol with a doubling time of about 90 min, and all of them produced an AdhE(A267T/E568K) . Purified AdhE(A267T) and AdhE(A267T/E568K) showed highly elevated acetaldehyde dehydrogenase activities . It therefore appears that when AdhE catalyzes the two sequential reactions in the counter-physiological direction, acetaldehyde dehydrogenation is the rate-limiting step . Both mutant proteins were more thermosensitive than the wild-type protein, but AdhE(A267T/E568K) was more thermal stable than AdhE(A267T) . Since both mutant enzymes exhibited similar kinetic properties, the second mutation probably conferred an increased growth rate on ethanol by stabilizing AdhE(A267T). Mikrobiologiia, 2000 May-Jun, 69(3), 410 - 4 {Saccharomyces bayanus var . Uvarum comb.nov., a new variety established by genetic analysis}; Naumov GI; Partial genetic isolation of two Saccharomyces bayanus varieties, S . bayanus var . bayanus and S . bayanus var . uvarum comb . nov., was established by hybridological analysis . The hybrids of these two varieties were semisterile: their ascospores were characterized by low survival . Earlier, the new variety was described as a group of cryophilic wine yeast cultivars capable of fermenting melibiose. Acta Vet Scand, 2000, 41(1), 25 - 40 Functional anatomy of the omasum in high Arctic Svalbard reindeer (Rangifer tarandus platyrhynchus) and Norwegian reindeer (Rangifer tarandus tarandus); Mathiesen SD et al.; The structure and fill of the omasum was investigated in summer and in winter in adult female reindeer living on the polar desert and tundra of the high Arctic archipelago of Svalbard and in sub-Arctic mountain habitats in northern Norway . The mean total mass of the omasum in non-lactating adult female Svalbard reindeer was 467 g (0.65 g per 100 g live body mass (BM)) in September and 477 g (1.03 g per 100 g BM) in April . By contrast, the mean mass of the omasum in non-lactating adult reindeer in northern Norway was 534 g (0.83 g per 100 g BM) in September but only 205 g (0.35 g per 100 g BM p < 0.05) in late March, owing to a decrease in both tissue mass and the wet mass of the contents of the organ . The mean absorptive surface of the omasum in Svalbard reindeer was 2300 cm2 in September and 2023 cm2 in April . In Norwegian reindeer, by contrast, the absorptive surface area decreased from 2201 cm2 in September to 1181 cm2 (p < 0.05) in late March . The marked seasonal decline of omasal tissue and contents in Norwegian reindeer probably results from intake of highly digestible forage plants, including lichens, in winter . Svalbard reindeer, a non-migratory sub-species, survive eating poor quality fibrous vascular plants in winter . The absence of any marked seasonal change in the mass, total absorptive surface area or filling of the omasum in Svalbard reindeer in winter despite a substantial decline in body mass presumably reflects their need to maintain maximum absorption of nutrients, including volatile fatty acids, when feeding on such poorly fermentable forage. Rapid Commun Mass Spectrom, 2000, 14(15), 1417 - 24 Pyrolysis/gas chromatography/mass spectrometry monitoring of fungal-biotreated distillery wastewater using Trametes sp . I-62 (CECT 20197); Gonzalez T et al.; Distillery wastewaters generated by ethanol production from fermentation of sugar-cane molasses, named vinasses, lead to important ecological impact due to their high content of soluble organic matter and their intense dark-brown color . Taking advantage of the well-known ability of white-rot fungi to degrade an extensive variety of organic pollutants, the capacity of Trametes sp . I-62 (CECT 20197) to detoxify this type of effluents was evaluated . In this work, pyrolysis/gas chromatography/mass spectrometry was applied to the chemical characterization of several fractions of Cuban distillery wastewater as well as to monitoring the changes which occurred after fungal treatment with this white-rot basidiomycete . Maximum effluent decolorization values and chemical oxygen demand reduction attained after seven days of fungal treatment were 73.3 and 61.7%, respectively, when 20% (v/v) of distillery vinasses was added to the culture medium . Under these conditions a 35-fold increase in laccase production by Trametes sp . I-62 was measured, but no manganese peroxidase activity could be detected . The pyrolysis/gas chromatography/mass spectrometry results showed a decrease in a number of pyrolysis products after seven days of fungal treatment, mainly furan derivatives . The decrease in the relative areas of these compounds could be related to the vinasse color-removal associated with melanoidin degradation . All these results indicated the potential use ofTrametes sp . I-62 in the detoxification of recalcitrant distillery vinasses . Am J Clin Nutr, 2000 Aug, 72(2), 432 - 8 Digestion of so-called resistant starch sources in the human small intestine; Vonk RJ et al.; BACKGROUND: Resistant starch sources, which are only partially digested in the small intestine, can be used to increase colonic availability of short-chain fatty acids . OBJECTIVE: To study the characteristics of the fermentation of resistant starch, the digestion of resistant starch in the small intestine has to be quantified . We compared the metabolic fates of highly digestible cornstarch (DCS), Hylon VII (type 2 resistant starch), and Novelose 330 (type 3 resistant starch), which are of corn origin and, therefore, naturally enriched in (13)C . DESIGN: After administration of 40 g starch or glucose to 7 healthy volunteers, glucose and exogenous glucose concentrations in serum and (13)CO(2) excretion in breath were analyzed for 6 h . (13)C abundance in carbon dioxide was analyzed by isotope ratio mass spectrometry (IRMS) and (13)C abundance in glucose by gas chromatography-combustion IRMS . RESULTS: By comparing the area under the curve (2 h) of exogenous glucose concentration in serum ((13)C glycemic index) after intake of starch or glucose, (13)C glycemic indexes for DCS, Hylon VII, and Novelose 330 were calculated to be 82 +/- 23%, 44 +/- 16%, and 43 +/- 15%, respectively . Comparison of 6-h cumulative percentage dose recovery in breath showed that 119 +/- 28% of DCS, 55 +/- 23% of Hylon VII, and 50 +/- 26% of Novelose 330 was digested in the small intestine . CONCLUSION: The exogenous glucose response in serum and the (13)CO(2) excretion in breath can be used to estimate small intestinal digestion of resistant starch, which amounts to approximately 50%. J Food Prot, 2000 Jul, 63(7), 934 - 9 Effects of gamma radiation on sensory qualities, microbiological and chemical properties of salted and fermented squid; Byun MW et al.; The effects of gamma radiation on sensory quality, microbial population, and chemical properties of salted and fermented squid were investigated . Squid (Todarodes pacificus) was sliced, washed, and then salted with 5, 10, and 20% (wt/wt) sodium chloride . Salted squid was irradiated with dosages of 0, 2.5, 5.0, and 10 kGy of gamma radiation and fermented at 15 degrees C for 50 days . Proximate composition, salinity, water activity, sensory evaluation, and total microbiological populations were examined . Chemical analyses providing information on degree of fermentation, such as amino nitrogen (AN), volatile basic nitrogen (VBN), trimethylamine (TMA), and hypoxanthine (Hx) were also conducted . Irradiated squid was not different in proximate composition, salinity, and water activity from nonirradiated squid . Sensory evaluation scores, total bacteria populations, and pH values were variable depending on salt concentration and irradiation dose . During fermentation, AN, VBN, TMA, and Hx contents increased rapidly as the salt concentration and irradiation dose decreased . Specifically, these chemical compounds of salted and fermented squid prepared with 10% salt and 10 kGy of gamma radiation maintained the appropriate level of fermentation . The present results showed that the combination of low salt concentration (10%) and gamma radiation was effective in processing salted and fermented squid and extending its shelf life compared to control (20% of salt) without adding any food additives. FEMS Microbiol Lett, 2000 Aug 1, 189(1), 81 - 7 Direct profiling of the yeast dynamics in wine fermentations; Cocolin L et al.; We present a method to directly characterize the yeast diversity present in wine fermentations by employing denaturing gradient gel electrophoresis (DGGE) of polymerase chain reaction (PCR)-amplified 26S ribosomal RNA (rRNA) genes . PCR-DGGE of a portion of the 26S rRNA gene was shown to distinguish most yeast genera associated with the production of wine . With this method the microbial dynamics in several model wine fermentations were profiled . PCR-DGGE provided a qualitative assessment of the yeast diversity in these fermentations accurately identifying populations as low as 1000 cells ml(-1) . PCR-DGGE represents an attractive alternative to traditional plating schemes for analysis of the microbial successions inherent in the fermentation of wine. FEMS Microbiol Lett, 2000 Aug 1, 189(1), 9 - 13 Cellular stress responses oscillate in synchronization with the ultradian oscillation of energy metabolism in the yeast Saccharomyces cerevisiae; Wang J et al.; We investigated whether cellular responses to various stress conditions are regulated in synchronization with the ultradian rhythm of respiratory-fermentative metabolism which is coupled to the cell cycle rhythm in continuous cultures of the yeast Saccharomyces cerevisiae . The cellular resistance to heat oscillated with a peak at the late respiro-fermentative phase, which approximately corresponds to the unbudding period of the cell cycle . Cellular resistance to H(2)O(2) and that to the superoxide-generating agent menadione oscillated in the same phase as that of heat resistance . The resistance to cadmium and that to 1-chloro-2,4-dinitrobenzene, an uncoupler of energy metabolism in mitochondria, both oscillated with a peak advanced by about 80 degrees relative to that of heat resistance, approximately covering the respiro-fermentative phase . Thus, cellular resistance to various stresses in S . cerevisiae oscillated in synchronization with the metabolic oscillation in the continuous culture. FEBS Lett, 2000 Jul 7, 476(3), 134 - 9 Mitochondrial Isa2p plays a crucial role in the maturation of cellular iron-sulfur proteins; Pelzer W et al.; The assembly of iron-sulfur (Fe/S) clusters in a living cell is mediated by a complex machinery which, in eukaryotes, is localised within mitochondria . Here, we report on a new component of this machinery, the protein Isa2p of the yeast Saccharomyces cerevisiae . The protein shares sequence similarity with yeast Isa1p and the bacterial IscA proteins which recently have been shown to perform a function in Fe/S cluster biosynthesis . Like the Isa1p homologue, Isa2p is localised in the mitochondrial matrix as a soluble protein . Deletion of the ISA2 gene results in the loss of mitochondrial DNA and a strong growth defect . Simultaneous deletion of the ISA1 gene does not further exacerbate this growth phenotype suggesting that the Isa proteins perform a non-essential function . When Isa2p was depleted by regulated gene expression, mtDNA was maintained, but cells grew slowly on non-fermentable carbon sources . The maturation of both mitochondrial and cytosolic Fe/S proteins was strongly impaired in the absence of Isa2p . Thus, Isa2p is a new member of the Fe/S cluster biosynthesis machinery of the mitochondrial matrix and may be involved in the binding of an intermediate of Fe/S cluster assembly. J Bacteriol, 2000 Aug, 182(16), 4632 - 6 Demonstration of a novel glycolytic pathway in the hyperthermophilic archaeon Thermococcus zilligii by (13)C-labeling experiments and nuclear magnetic resonance analysis; Xavier KB et al.; The operation of a novel glycolytic pathway was demonstrated in nongrowing cells of Thermococcus zilligii by analysis of the isotopic enrichment in the end products derived from fermentation of (13)C-labeled glucose . The new pathway involved the formation of formate, derived from C-1 in glucose, via cleavage of a six-carbon carboxylic acid. Carcinogenesis, 2000 Aug, 21(8), 1513 - 9 Morphodensitometric analysis of protein kinase C beta(II) expression in rat colon: modulation by diet and relation to in situ cell proliferation and apoptosis; Davidson LA et al.; We have recently demonstrated that overexpression of PKC beta(II) renders transgenic mice more susceptible to carcinogen-induced colonic hyperproliferation and aberrant crypt foci formation . In order to further investigate the ability of PKC beta(II) to modulate colonocyte cytokinetics, we determined the localization of PKC beta(II) with respect to cell proliferation and apoptosis along the entire colonic crypt axis following carcinogen and diet manipulation . Rats were provided diets containing either corn oil {containing n-6 polyunsaturated fatty acids (PUFA)} or fish oil (containing n-3 PUFA), cellulose (non-fermentable fiber) or pectin (fermentable fiber) and injected with azoxymethane (AOM) or saline . After 16 weeks, an intermediate time point when no macroscopic tumors are detected, colonic sections were utilized for immunohistochemical image analysis and immunoblotting . Cell proliferation was measured by incorporation of bromodeoxyuridine into DNA and apoptosis by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling . In the distal colon, PKC beta(II) staining was localized to the upper portion of the crypt . In comparison, proximal crypts had more (P < 0.05) staining in the lower tertile . AOM enhanced (P < 0.05) PKC beta(II) expression in all regions of the distal colonic crypt (upper, middle and lower tertiles) . There was also an interaction (P < 0.05) between dietary fat and fiber on PKC beta(II) expression (corn/pectin > fish/cellulose, fish/pectin > corn/cellulose) in all regions of the distal colonic crypt . With respect to colonic cell kinetics, proliferation paralleled the increase in PKC beta(II) expression in carcinogen-treated animals . In contrast, apoptosis at the lumenal surface was inversely proportional to PKC beta(II) expression in the upper tertile . These results suggest that an elevation in PKC beta(II) expression along the crypt axis in the distal colon is linked to enhancement of cell proliferation and suppression of apoptosis, predictive intermediate biomarkers of tumor development . Therefore, select dietary factors may confer protection against colon carcinogenesis in part by blocking carcinogen-induced PKC beta(II) expression. Bioelectrochemistry, 2000 Jun, 51(2), 151 - 6 Redox potential is a determinant in the Escherichia coli anaerobic fermentative growth and survival: effects of impermeable oxidant; Bagramyan K et al.; Decrease of redox potential (Eh) down to -550-600 mV in the Escherichia coli culture is observed during growth in either anaerobic or aerobic conditions . The E . coli growth and survival under anaerobic fermentative conditions were found to be strongly inhibited by potassium ferricyanide in the concentration of 1 mM, when Eh was decreased to -50-100 mV . This oxidant also resulted in approximately 2-fold decrease of total and N,N'-dicyclohexylcarbodiimide (DCCD)-inhibited H+ efflux, 2.5-fold inhibition in K+ influx, 1.5-fold less K+ accumulation, and delayed a decrease in Eh to negative values by bacteria . K3{Fe(CN)6} was shown to block an ATP-dependent increase in the amount of accessible thiol groups of membrane vesicles that was inhibited by DCCD, and this inhibition by the oxidant could be recovered by dithiothreitol . These effects were not observed with cells growing under aerobic conditions . The effects of K3{Fe(CN)6}, an impermeable oxidant, might be explained by the fact that redox potential is a determinant in the E . coli anaerobic fermentative growth and survival that has a regulatory role in maintaining H+ and K fluxes and the number of accessible thiol groups on membrane. J Biotechnol, 2000 Jun 23, 80(2), 135 - 42 Improved secondary metabolite production in the genus Streptosporangium by optimization of the fermentation conditions; Pfefferle C et al.; The cultivation of strains of the genus Streptosporangium in batch fermentations demonstrated that the optimal conditions for secondary metabolite production are completely different to those of the closely related genus Streptomyces . The dissolved oxygen tension (pO(2)) was identified as an important parameter for optimal production of secondary metabolites in submerged cultures . Extreme variations of this parameter by changes in aeration (gas flow), agitation system and stirrer speed showed a tremendous impact in production yields of all investigated strains . Finally, a 20-fold increase in productivity was observed by conditions of controlled oxygen excess compared to optimal fermentation conditions for Streptomyces strains. FEBS Lett, 2000 Jul 21, 477(3), 219 - 23 Trichodion, a new inhibitor of inflammatory signal transduction pathways from a Trichosporiella species; Erkel G; In a search for new inhibitors of the IFN-gamma mediated signal transduction in HeLa S3 cells using secreted alkaline phosphatase (SEAP) as reporter gene, the novel pyran-dione trichodion was isolated from fermentations of the imperfect fungus Trichosporiella sp . 20-95 . The compound inhibits the IFN-gamma mediated expression of the reporter gene with IC(50) values of 21-42 microM (5-10 microgram/ml) . The NF-kappaB and AP-1 mediated expression of the reporter gene are inhibited with IC(50) values of 42-84 microM (10-20 microgram/ml) and 21 microM (5 microgram/ml) respectively . Western blotting with COX-2 and NOS II antibodies showed that the expression of both proinflammatory enzymes is almost completely inhibited at 21-42 microM (5-10 microgram/ml) in LPS/IFN-gamma stimulated J774 mouse macrophages . Studies on the mode of action of the compound revealed that the inhibition of the NF-kappaB dependent pathway is due to the stabilization of the IkappaB protein and the inhibition of the IFN-gamma dependent signaling is caused by an inhibition of the phosphorylation of the STAT1alpha transcription factor. J Antibiot (Tokyo), 2000 May, 53(5), 496 - 501 Identification of inhibitors of inducible nitric oxide synthase from microbial extracts; Alvi KA et al.; A new member of the angucycline family, vineomycin C (3), together with four known metabolites saquayamycin A1 (1), A-7884 (2), rabelomycin (5) and xanthomegnin (6) were isolated from microbial extracts . The structures were determined by 1D and 2D NMR techniques and chemical degradation . Compounds 1-3 and 5 were isolated from a fermentation of Streptomyces sp., while 6 was isolated from a fungal fermentation extract . All five compounds have shown potent inhibitory activity in the inducible nitric oxide synthase (iNOS) assay. J Antibiot (Tokyo), 2000 May, 53(5), 479 - 83 IB-96212, a novel cytotoxic macrolide produced by a marine Micromonospora . II . Physico-chemical properties and structure determination; Canedo LM et al.; IB-96212, is a new member of spiroketal containing macrolide class of fermentation-derived natural products isolated from mycelial extracts of Micromonospora sp . The structure consists of a new aglycone which possesses a 26-membered macrolide ring system and of one deoxy sugar identified as L-rhodinose, this structure represents the first reported spiroketal macrolide natural product related to other macrolides, such as oligomycins, dunaimycins, citovaricin, rutamycin and ossamycin. J Antibiot (Tokyo), 2000 May, 53(5), 474 - 8 IB-96212, a novel cytotoxic macrolide produced by a marine Micromonospora . I . Taxonomy, fermentation, isolation and biological activities; Fernandez-Chimeno RI et al.; A novel bioactive macrolide, IB-96212 has been isolated from the fermentation broth of a marine actinomycete, L-25-ES25-008 . The strain belongs to the genus Micromonospora . The macrolide showed a very strong cytotoxic activity against P-388, and lower but significant activity against A-549, HT-29, and MEL-28 cell lines . We describe the isolation, taxonomy and fermentation of the producing strain as well as the isolation of IB-96212. J Dairy Sci, 2000 Jul, 83(7), 1598 - 624 Effects of diet on short-term regulation of feed intake by lactating dairy cattle; Allen MS; Physical and chemical characteristics of dietary ingredients and their interactions can have a large effect on dry matter intake (DMI) of lactating cows . Physical limitations caused by distension of the reticulo-rumen or other compartments of the gastrointestinal tract often limit DMI of high producing cows or cows fed high forage diets . Fermentation acids also limit DMI from a combination of increased osmolality in the reticulo-rumen and specific effects of propionate, although the mechanisms are not clear . The specific physical and chemical characteristics of diets that can affect DMI include fiber content, ease of hydrolysis of starch and fiber, particle size, particle fragility, silage fermentation products, concentration and characteristics of fat, and the amount and ruminal degradation of protein . Site of starch digestion affects the form of metabolic fuel absorbed, which can affect DMI because absorbed propionate appears to be more hypophagic than lactate or absorbed glucose . Dry matter intake is likely determined by integration of signals in brain satiety centers . Difficulty in measurement and extensive interactions among the variables make it challenging to account for dietary effects when predicting DMI . However, a greater understanding of the mechanisms along with evaluation of animal responses to diet changes allows diet adjustments to be made to optimize DMI as well as to optimize allocation of diet ingredients to animals . This paper discusses some of the characteristics of dietary ingredients that should be considered when formulating diets for lactating dairy cows and when allocating feeds to different groups of animals on the farm. J Dairy Sci, 2000 Jul, 83(7), 1520 - 9 Milk production and composition, rumen fermentation parameters, and grazing behavior of dairy cows supplemented with different forms and amounts of corn grain; Soriano FD et al.; The objectives were to compare milk production and composition, change in body weight and body condition score, rumen fermentation parameters and grazing patterns by cows when supplemented with different forms and amounts of corn grain . In experiment 1, 36 Holstein cows were supplemented with either 6, 6, 6, or 4 kg/d of dry matter of high moisture corn, coarsely ground corn, finely ground corn, or high moisture corn in two equal daily feedings, respectively . Milk yield (30.3 kg/d), milk protein (2.97%), and milk urea N (14.7 mg/dl) were not different among treatments . Body weight change and body condition score change were similar (23.1 kg and -0.24) for the 10-wk study . During experiment 2, four rumen cannulated cows in midlactation were supplemented with 6 kg/d of dry matter from either coarsely ground corn or high moisture corn in two equal feedings after milking . After the p.m . milking, ruminal pH was measured and rumen fluid samples, were collected from cows to determine ammonia N and volatile fatty acids at 0.5, 1, 2, 3, ...8 h post-corn feeding during grazing . Ruminal pH values were similar for corn supplements, and, with one exception, were 6.0 or below between 5 and 8 h . Ruminal ammonia-N concentrations reached a maximum at 7 h also . In experiment 3, 40 cows were observed for grazing behavior every 30 min for two consecutive days . Cows grazed an average of 6.4 h/d, 4.1 h in the afternoon and 2.3 h in the morning . Milk yield, milk composition, change in body weight, and body condition were similar regardless of the type or amount of corn supplemented. Nahrung, 2000 Jun, 44(3), 207 - 10 Biosynthesis of nutraceutical iso-oligosaccharides by multiple forms of transferase produced by Aspergillus foetidus; Wang XD et al.; Isomalto-oligosaccharide and isofructo-oligosaccharide production was attempted using enzymes produced by Aspergillus foetidus . Four fractions having transferase enzyme activity were obtained from the fermentation broth of Aspergillus foetidus by ammonium sulfate precipitation and DEAE-cellulose chromatography . The optimum temperature was 60 degrees C and pH stability in the range 4 to 6 for various fractions . The pH optima, heat sensitivity and kinetic parameters for the four fractions were however not the same . All four enzyme fractions could not utilize lactose and cellobiose to synthesize isooligosaccharide and showed different transferase activity for maltose and sucrose for synthesis of isooligosaccharides . The HPLC isooligosaccharide product analysis of these transferase enzymes reveal that the four forms of enzymes are distinct and produce oligosaccharides like panose, kestose and nystose or act as hydrolytic enzymes, depending on reaction conditions. Anal Biochem, 2000 Aug 1, 283(2), 192 - 9 Determination of carbohydrates, sugar alcohols, and glycols in cell cultures and fermentation broths using high-performance anion-exchange chromatography with pulsed amperometric detection; Hanko VP et al.; Cell cultures and fermentation broths are complex mixtures of organic and inorganic compounds . Many of these compounds are synthesized or metabolized by microorganisms, and their concentrations can impact the yields of desired products . Carbohydrates serve as carbon sources for many microorganisms, while sugar alcohols (alditols), glycols (glycerol), and alcohols (methanol and ethanol) are metabolic products . We used high-performance anion-exchange chromatography with pulsed amperometric detection (HPAE-PAD) to simultaneously analyze for carbohydrates, alditols, and glycerol in growing yeast (Saccharomyces cerevisiae) cultures and their final fermentation broths . Both cultures were grown on complex undefined media, aliquots centrifuged to remove particulates, and the supernatants diluted and directly injected for analysis . Pulsed amperometry allowed a direct detection of the carbohydrates, alditols, and glycols present in the cultures and fermentation broths with very little interference from other matrix components . The broad linear range of three to four orders of magnitude allowed samples to be analyzed without multiple dilutions . Peak area RSDs were 2-7% for 2, 3-butanediol, ethanol, glycerol, erythritol, rhamnose, arabitol, sorbitol, galactitol, mannitol, arabinose, glucose, galactose, lactose, ribose, raffinose, and maltose spiked into a heat-inactivated yeast culture broth supernatant that was analyzed repetitively for 48 h . This method is useful for directly monitoring culture changes during fermentation . The carbohydrates in yeast cultures were monitored over 1 day . A yeast culture with medium consisting primarily of glucose and trace levels of trehalose and arabinose showed a drop in sugar concentration over time and an increase in glycerol . Yeast growing on a modified culture medium consisting of multiple carbohydrates and alditols showed preference for specific carbon sources and showed the ability to regulate pathways leading to catalysis of alternative carbon sources . J Chromatogr A, 2000 Jun 9, 881(1-2), 517 - 30 Liquid chromatographic determination of biogenic amines in fermented foods after derivatization with 3,5-dinitrobenzoyl chloride; Kirschbaum J et al.; The reagent 3,5-dinitrobenzoyl chloride (DNBZ-Cl) was tested for pre-column derivatization of biogenic amines (BAs) . Samples were derivatized within 3 min in 1 M NaOH at ambient temperature by adding 2-propanole and 50 mM DNBZ-Cl in acetonitrile . The reaction was terminated by addition of 2 M HCl . For high-performance liquid chromatography an encapsulated stationary reversed-phase and gradient elution using a ternary gradient system were used . The DNBZ derivatives were quantified by their UV-absorption at 260 nm . The structures of the derivatives were elucidated using coupling of HPLC with electrospray ionization mass spectrometry . Detection limits of BAs were approximately 124-864 microg l(-1) (injected amounts 203-1410 pg) at a signal-to-noise ratio of 3:1 . The coefficients of determination were 0.989-0.996, with the exceptions of cadaverine (0.976) and serotonin (0.965) . The method was applied to the quantitative determination of agmatine, cadaverine, histamine, octopamine, 2-phenylethylamine, putrescine, serotonin, spermidine, spermine, tryptamine and tyramine, in fermented cabbage juices, soy sauces, Misos (soy pastes), fermented fish sauces, and anchovy paste. J Chromatogr A, 2000 Jun 9, 881(1-2), 285 - 97 Chromatographic determination of riboflavin and its derivatives in food; Gliszczynska-Swiglo A et al.; Three elution methods on two different reversed-phase C18 columns were developed to determine flavin derivatives in raw egg white, raw egg yolk, egg powder, pasteurised milk, fermented milk products and liver (chicken, calf and pig) . Additionally, 11 thin-layer chromatography solvent systems were used to confirm presence of flavins detected in assessed products . It was found that an Alphabond C18 column was not as effective as a Symmetry C18 column . Method A (mobile phase gradient of methanol-0.05 M ammonium acetate, pH 6.0 applied on an Alphabond C18 column) can be used for determination of flavin adenine dinucleotide, flavin mononucleotide, riboflavin 4',5'-cyclic phosphate, riboflavin, 10-formylmethylflavin and 10-hydroxyethylflavin in products that do not contain 7alpha-hydroxyriboflavin . Method B (mobile phase gradient of methanol-demineralized water, on an Alphabond C18 column) can be useful to separate flavin coenzymes from other flavin compounds or to confirm the presence of 7alpha-hydroxyriboflavin and 10-hydroxyethylflavin in analysed samples . Method C (mobile phase gradient of methanol-0.05 M ammonium acetate, pH 6.0, on a Symmetry C18 column) allows separation of all flavins detected in tested products: flavin adenine dinucleotide, flavin mononucleotide, riboflavin 4',5'-cyclic phosphate, riboflavin, 10-formylmethylflavin, 10-hydroxyethylflavin, 7alpha-hydroxyriboflavin, riboflavin-beta-D-galactoside and riboflavin-alpha-D-glucoside. J Chromatogr A, 2000 Jun 9, 881(1-2), 81 - 91 Chromatographic determination of amino acid enantiomers in beers and raw materials used for their manufacture; Erbe T et al.; Using gas chromatography (GC) on a chiral stationary phase, accompanied by high-performance liquid chromatography, beers and raw materials used for manufacturing (hops, barley grains, malts) were investigated for the pattern and quantities of amino acid enantiomers . Although L-amino acids were most abundant, certain D-amino acids were detected in all beers and most of the raw materials . Highest amounts of D-amino acids were detected in special beers such as Berliner Weisse that underwent bottle-conditioning with lactic cultures, and Belgian fruit beers produced by spontaneous fermentation . It is demonstrated that GC on chiral stationary phases is highly suitable for the quantitative determination of amino acid enantiomers in beers and raw materials used for their manufacture . Quantities, relative amounts and pattern of amino acid enantiomers can serve in particular as chiral markers for the authenticity of special beers. J Clin Invest, 2000 Jul, 106(2), 281 - 7 Congenital sucrase-isomaltase deficiency arising from cleavage and secretion of a mutant form of the enzyme; Jacob R et al.; Congenital sucrase-isomaltase deficiency (CSID) is an autosomal recessive human intestinal disorder that is clinically characterized by fermentative diarrhea, abdominal pain, and cramps upon ingestion of sugar . The symptoms are the consequence of absent or drastically reduced enzymatic activities of sucrase and isomaltase, the components of the intestinal integral membrane glycoprotein sucrase-isomaltase (SI) . Several known phenotypes of CSID result from an altered posttranslational processing of SI . We describe here a novel CSID phenotype, in which pro-SI undergoes an unusual intracellular cleavage that eliminates its transmembrane domain . Biosynthesis of pro-SI in intestinal explants and in cells transfected with the SI cDNA of this phenotype demonstrated a cleavage occurring within the endoplasmic reticulum due to a point mutation that converts a leucine to proline at residue 340 of isomaltase . Cleaved pro-SI is transported to and processed in the Golgi apparatus and is ultimately secreted into the exterior milieu as an active enzyme . To our knowledge this is the first report of a disorder whose pathogenesis results not from protein malfolding or mistargeting, but from the conversion of an integral membrane glycoprotein into a secreted species that is lost from the cell surface. Australas Radiol, 1999 Feb, 43(1), 37 - 40 The role of computed tomography in the diagnosis of arterial gas embolism in fatal diving accidents in Tasmania; Oliver J et al.; Four cases of fatal diving accidents in Tasmania are presented, highlighting the role of CT in the investigation of diving fatalities . The CT technique allows rapid diagnosis when arterial gas embolism (AGE) is suspected . The traditional method of investigation, underwater autopsy, is a difficult procedure that requires specialized training in which the subtle diagnosis of AGE may be completely missed . Facilities for performing underwater autopsies are normally available only in tertiary referral centres, and therefore the diagnosis of AGE may be missed due to lack of facilities . The use of CT in the diagnosis of AGE in divers was first utilized in the early 1980s but has still not become widely adopted in forensic practice . This radiological technique has the advantage of being sensitive, quick, reliable, readily available and provides a permanent record . For hospitals that do not have a resident forensic pathologist, a CT scan can be easily performed and interpreted to eliminate the possibility of AGE . There are a number of pitfalls in the diagnosis of AGE with CT, particularly intravascular gas production following postmortem fermentation and off-gassing . Awareness of these pitfalls will help the radiologist in making a correct diagnosis of AGE. J Chromatogr Sci, 2000 Jul, 38(7), 307 - 14 Determination of major aroma impact compounds in fermented cucumbers by solid-phase microextraction--gas chromatography--mass spectrometry--olfactometry detection; Marsili RT et al.; Purge-and-trap, solid-phase extraction, and solid-phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS) sample preparation techniques for the analysis of odor impact chemicals in fermented cucumber brine are compared . SPME-GC-MS is coupled with detection frequency olfactometry experiments to determine key impact odor compounds in the brine . The most potent odorants that define the typical characteristic brine aroma are trans-4-hexenoic acid and cis-4-hexenoic acid . Confirmation of key impact odorants in brine is confirmed by recombination experiments. Trends Biotechnol, 2000 Aug, 18(8), 356 - 60 Defined media and inert supports: their potential as solid-state fermentation production systems; Ooijkaas LP et al.; Solid-state fermentation (SSF) using inert supports impregnated with chemically defined liquid media has several potential applications in both scientific studies and in the industrial production of high-value products, such as metabolites, biological control agents and enzymes . As a result of its more defined system, SSF on inert supports offers numerous advantages, such as improved process control and monitoring, and enhanced process consistency, compared with cultivation on natural solid substrates. Biochim Biophys Acta, 2000 Jul 14, 1480(1-2), 171 - 81 A non-specific aminopeptidase from Aspergillus; Blinkovsky AM et al.; A fermentation broth supernatant of the Aspergillus oryzae strain ATCC20386 contains aminopeptidase activity that releases a wide variety of amino acids from natural peptides . The supernatant was fractionated by anion exchange chromatography . Based on the primary amino acid sequence data obtained from proteins in certain fractions, polymerase chain reaction (PCR) primers were made and a PCR product was generated . This PCR product was used to screen an A . oryzae cDNA library from which the full length gene was then obtained . Fusarium venenatum and A . oryzae were used as hosts for gene expression . Transformed strains of both F . venenatum and A . oryzae over-expressed an active aminopeptidase (E.C . 3.4.11), named aminopeptidase II . The recombinant enzyme from both fungal hosts appeared as smears on sodium dodecyl sulfate-polyacrylamide gel electrophoresis . After deglycosylation of the N-linked sugars, both samples were a sharp band at approximately 56 kDa and had identical N-terminal amino acid sequences . Aminopeptidase II is a metalloenzyme with, presumably, Zn in the active site . Using various natural peptides and para-nitroanilides (pNAs) of amino acids as substrates, the aminopeptidase was found to be non-specific . Only X-Pro bonds demonstrated resistance to hydrolysis catalyzed by this aminopeptidase . The optimal enzyme activity was observed at pH 9.5 and 55 degrees C . Among amino acid pNAs, Leu-pNA appears to have the highest value of bimolecular constant of 40 min(-1) mM(-1) (k(cat) = 230 min(-1); K(m) = 5.8 mM) at pH 7.5 and 21 degrees C . Among Xaa-Ala-Pro-Tyr-Lys-amide pentapeptides, the velocity of catalytic hydrolysis at pH 7.5 and 21 degrees C was in a decreasing order: Pro, Ala, Leu, Gly and Glu. Enzyme Microb Technol, 2000 Aug 1, 27(3-5), 337 - 344 A mathematical model of the formation of fermentable sugars from starch hydrolysis during high-temperature mashing; Muller R; During the mashing process of brewing, activity of the amylolytic enzymes decays due to the high temperatures used to gelatinise the starch . Because the different enzymes produce different sugars, high temperatures can be exploited to modify the fermentability of resulting worts . This is especially useful when producing low alcohol beers . The expression a.exp(b.t)-c.exp(d.t) (where t is the temperature of the mash in degrees C) provides a simple but useful description of the activity of the amylases . Combining the activities of alpha- and beta-amylases results in a prediction of the resulting fermentability . A simple modification to the expression accommodates changes in mash thickness . The error of prediction is approximately 3 degrees of fermentability . The model is not appropriate for predicting the fermentability of worts produced at the lower standard mashing temperatures . It can be used without the necessity of analytical parameters so analyses that the brewer would not normally perform are not required . If increased accuracy is needed, the results of two previous mashes can be used to modify the parameters used. Enzyme Microb Technol, 2000 Aug 1, 27(3-5), 312 - 318 Heterotrophic production of biomass and lutein by Chlorella protothecoides on various nitrogen sources; Shi X et al.; The effects of nitrate, ammonium, and urea as nitrogen sources on the heterotrophic growth of Chlorella protothecoides were investigated using flask cultures . No appreciable inhibitory effect on the algal growth was observed over a nitrogen concentration range of 0.85-1.7 g l(-)(1) . In contrast, differences in specific growth rate and biomass production were found among the cultures with the various nitrogen compounds . The influence of different nitrogen sources at a concentration equivalent to 1.7 g l(-)(1) nitrogen on the heterotrophic production of biomass and lutein by C . protothecoides was investigated using the culture medium containing 40 g l(-)(1) glucose as the sole carbon and energy source in fermentors . The maximum biomass concentrations in the three cultures with nitrate, ammonium, and urea were 18.4, 18.9, and 19.6 g l(-)(1) dry cells, respectively . The maximum lutein yields in these cultures were between 68.42 and 83.81 mg l(-)(1) . The highest yields of both biomass and lutein were achieved in the culture with urea . It was therefore concluded that urea was the best nitrogen source for the production of biomass and lutein . Based on the experimental results, a group of kinetic models describing cell growth, lutein production, and glucose and nitrogen consumption were proposed and a satisfactory fit was found between the experimental results and predicted values . Dynamic analysis of models demonstrated that enhancing initial nitrogen concentration in fermentor cultures, which correspondingly enhances cell growth and lutein formation, may shorten the fermentation cycle by 25-46%. Biotechnol Bioeng, 2000 Sep 5, 69(5), 537 - 47 Effect of carbon and nitrogen sources on growth dynamics and exopolysaccharide production for the hyperthermophilic archaeon Thermococcus litoralis and bacterium Thermotoga maritima; Rinker KD et al.; Batch and continuous cultures were used to compare specific physiological features of the hyperthermophilic archaeon, Thermococcus litoralis (T(opt) of 85 degrees to 88 degrees C), to another fermentative hyperthermophile that reduces S degrees facultatively, that is, the bacterium Thermotoga maritima (T(opt) of 80 degrees to 85 degrees C) . Under nutritionally optimal conditions, these two hyperthermophiles had similar growth yields on maltose and similar cell formula weights based on elemental analysis: CH(1.7)O(0 . 7)N(0.2)S(0.006) for T . litoralis and CH(1.6)O(0.6)N(0.2)S(0.005) for T . maritima . However, they differed with respect to nitrogen source, fermentation product patterns, and propensity to form exopolysaccharides (EPS) . T . litoralis could be cultured in the absence or presence of maltose on an amino acid-containing defined medium in which amino acids served as the sole nitrogen source . T . maritima, on the other hand, did not utilize amino acids as carbon, energy, or nitrogen sources, and could be grown in a similar defined medium only when supplemented with maltose and ammonium chloride . Not only was T . litoralis unable to utilize NH(4)Cl as a nitrogen source, its growth was inhibited at certain levels . At 1 g/L ( approximately 20 mM) NH(4)Cl, the maximum growth yield (Y(x/s(max))) for T . litoralis was reduced to 13 g cells dry weight (CDW)/mol glucose from 40 g CDW/mol glucose in media lacking NH(4)Cl . Alanine production increased with increasing NH(4)Cl concentrations and was most pronounced if growth on NH(4)Cl was carried out in an 80% H(2) atmosphere . In T . maritima cultures, which would not grow in an 80% H(2) atmosphere, alanine and EPS were produced at much lower levels, which did not change with NH(4)Cl concentration . EPS production rose sharply at high dilution rates for both organisms, such that maltose utilization plots were biphasic . Wall growth effects were also noted, because cultures failed to wash out at dilution rates significantly above maximum growth rates determined from batch growth experiments . This study illustrates the importance of effective cultivation methods for addressing physiological issues related to the growth of hyperthermophilic heterotrophs . Biotechnol Bioeng, 2000 Sep 5, 69(5), 526 - 36 Effects of Ca(OH)(2) treatments ("overliming") on the composition and toxicity of bagasse hemicellulose hydrolysates; Martinez A et al.; Hemicellulose syrups from dilute sulfuric acid hydrolysates of hemicellulose contain inhibitors that prevent efficient fermentation by yeast or bacteria . It is well known that the toxicity of these hydrolysate syrups can be ameliorated by optimized "overliming" with Ca(OH)(2) . We have investigated the optimization of overliming treatments for sugar cane bagasse hydrolysates (primarily pentose sugars) using recombinant Escherichia coli LY01 as the biocatalyst . A comparison of composition before and after optimal overliming revealed a substantial reduction in furfural, hydroxymethylfurfural, and three unidentified high-performance liquid chromatography (HPLC) peaks . Organic acids (acetic, formic, levulinic) were not affected . Similar changes have been reported after overliming of spruce hemicellulose hydrolysates (Larsson et al., 1999) . Our studies further demonstrated that the extent of furan reduction correlated with increasing fermentability . However, furan reduction was not the sole cause for reduced toxicity . After optimal overliming, bagasse hydrolysate was rapidly and efficiently fermented (>90% yield) by LY01 . During these studies, titration, and conductivity were found to be in excellent agreement as methods to estimate sulfuric acid content . Titration was also found to provide an estimate of total organic acids in hydrolysate, which agreed well with the sum of acetic, levulinic, and