Appl Biochem Biotechnol, 2002 Spring, 98-100, 909 - 20 Enhancement of oxygen transfer by pressure pulsation in aqueous glycerol fermentation; Huang WC et al.; Aeration plays an important role in the production of glycerol by fermentation with yeast . Effective aeration depends on a number of factors, such as amount of air, fineness of air dispersion, rate of agitation, and time of gas-liquid contact . This investigation dealt with the effect of periodic variation in gas pressure on oxygen transfer measured by sulfite oxidation and glycerol fermentation in stirred tanks . The oxygen transfer rate measured with the sulfite oxidation method was improved by 20-30% under the condition of pressure pulsation (PP) at 30 degrees C . The yield and productivity of glycerol were increased by about 26 and 6.8%, respectively, in 48 h by employing a glucose concentration of 250 g/L with PP at 30 degrees C. Appl Biochem Biotechnol, 2002 Spring, 98-100, 875 - 83 Xylose reductase activity of Candida guilliermondii during xylitol production by fed-batch fermentation: selection of process variables; Rodrigues DC et al.; Xylose reductase activity of Candida guilliermondii FTI 20037 was evaluated during xylitol production by fed-batch fermentation of sugarcane bagasse hydrolysate . A 2(4-1) fractional factorial design was used to select process variables . The xylose concentrations in the feeding solution (S(F)) and in the fermentor (S0), the pH, and the aeration rate were selected for optimization of this process, which will be undertaken in the near future . The best experimental result was achieved at S(F) = 45 g/L, S0 = 40 g/L, pH controlled at 6.0, and aeration rate of 1.2 vvm . Under these conditions, the xylose reductase activity was 0.81 U/mg of protein and xylitol production was 26.3 g/L, corresponding to a volumetric productivity of 0.55 g/(L x h) and a xylose xylitol yield factor of 0.68 g/g. Appl Biochem Biotechnol, 2002 Spring, 98-100, 849 - 61 Recirculation of process streams in fuel ethanol production from softwood based on simultaneous saccharification and fermentation; Alkasrawi M et al.; The effect of process stream recirculation on ethanol production from steam- pretreated softwood based on simultaneous saccharification and fermentation (SSF) was investigated for two process configurations . In the first configuration, a part of the stillage stream after distillation was recycled and, in the second configuration, the liquid after SSF was recycled . The aim was to minimize the energy consumption in the distillation of the fermentation broth and in the evaporation of the stillage, as well as the use of fresh water . However, recirculation leads to an increased concentration of nonvolatiles in the first configuration, and of both volatiles and nonvolatiles in the second configuration . These substances might be inhibitory to the enzymes and the yeast in SSF . When 60% of the fresh water was replaced by stillage, the ethanol yield and the productivity were the same as for the configuration without recirculation . The ethanol production cost was reduced by 17% . In the second configuration, up to 40% of the fresh water could be replaced without affecting the final ethanol yield, although the initial ethanol productivity decreased . The ethanol production cost was reduced by 12% . At higher degrees of recirculation, fermentation was clearly inhibited, resulting in a decrease in ethanol yield while hydrolysis seemed unaffected. Appl Biochem Biotechnol, 2002 Spring, 98-100, 815 - 32 Enhancing the enzymatic hydrolysis of cellulosic materials using simultaneous ball milling; Mais U et al.; One of the limiting factors restricting the effective and efficient bioconversion of softwood-derived lignocellulosic residues is the recalcitrance of the substrate following pretreatment . Consequently, the ensuing enzymatic process requires relatively high enzyme loadings to produce monomeric carbohydrates that are readily fermentable by ethanologenic microorganisms . In an attempt to circumvent the need for larger enzyme loadings, a simultaneous physical and enzymatic hydrolysis treatment was evaluated . A ball-mill reactor was used as the digestion vessel, and the extent and rate of hydrolysis were monitored . Concurrently, enzyme adsorption profiles and the rate of conversion during the course of hydrolysis were monitored . alpha-Cellulose, employed as a model substrate, and SO2-impregnated steam-exploded Douglas-fir wood chips were assessed as the cellulosic substrates . The softwood-derived substrate was further posttreated with water and hot alkaline hydrogen peroxide to remove >90% of the original lignin . Experiments at different reaction conditions were evaluated, including substrate concentration, enzyme loading, reaction volumes, and number of ball beads employed during mechanical milling . It was apparent that the best conditions for the enzymatic hydrolysis of alpha-cellulose were attained using a higher number of beads, while the presence of air-liquid interface did not seem to affect the rate of saccharification . Similarly, when employing the lignocellulosic substrate, up to 100% hydrolysis could be achieved with a minimum enzyme loading (10 filter paper units/g of cellulose), at lower substrate concentrations and with a greater number of reaction beads during milling . It was apparent that the combined strategy of simultaneous ball milling and enzymatic hydrolysis could improve the rate of saccharification and/or reduce the enzyme loading required to attain total hydrolysis of the carbohydrate moieties. Appl Biochem Biotechnol, 2002 Spring, 98-100, 747 - 51 Production of coconut aroma by fungi cultivation in solid-state fermentation; de Alberto AA et al.; The production of 6-pentyl-alpha-pyrone (6-PP), an unsaturated D-lactone with a strong coconut-like aroma was studied and compared with liquid and solid substrates . A fungi strain that produces coconut aroma compound was selected . The liquid medium of the submerged culture was used to impregnate a solid support of sugarcane bagasse in SSF (Solid State Fermentation) . This substrate was adequate for growth and aroma production; the concentration obtained using SSF was higher than using liquid fermentation process . In the present work, it is demonstrated that, by solid-state-fermentation process, it is possible to produce 6-PP . The amount of 6-PP produced using a solid state substrate, following a 5 d culture, was 3 mg/g dry matter . Therefore, the amount of 6-PP produced during solid-state-fermentation process is higher than that reported in literature for submerged process. Appl Biochem Biotechnol, 2002 Spring, 98-100, 733 - 46 Modeling simultaneous saccharification and fermentation of softwood; Pettersson PO et al.; Simultaneous saccharification and fermentation (SSF) of wood has been modeled for the past 15-20 years, but the substrates used for model evaluation have so far not included pretreated softwood . In the present study, data from lab-scale batch SSF of SO2-impregnated, steam-pretreated spruce chips were used to evaluate a model found in the literature . The model, which was somewhat modified, consists of a number of nonlinear, coupled ordinary differential equations, which were solved numerically . Some parameter values were fitted to data by use of least-squares minimization . A difficulty in parameter estimation was the lack of cellobiose measurements, something that was relieved by adding assumptions about parameter relations . The simulated concentration profiles agreed well with the measured concentrations of glucose and ethanol . It is therefore concluded that the basic model features apply to softwood SSF . The model predicts rate saturation with respect to enzyme concentration at concentrations above 60 FPU/g cellulose, although this was not observed in the experimental data, which only comprised enzyme concentrations up to 32 FPU/g cellulose. Appl Biochem Biotechnol, 2002 Spring, 98-100, 717 - 32 Ethanol production from olive oil extraction residue pretreated with hot water; Ballesteros I et al.; The olive pulp fraction contained in the residue generated in olive oil extraction by a two-step centrifugation process can be upgraded by using the cellulose fraction to produce ethanol and recovering high value phenols (tyrosol and hydroxytyrosol) . Olive pulp was pretreated in a laboratory scale stirred autoclave at different temperatures (150-250 degrees C) . Pretreatment was evaluated regarding cellulose recovery, enzymatic hydrolysis effectiveness, ethanol production by a simultaneous saccharification and fermentation process (SSF), and phenols recovery in the filtrate . The pretreatment of olive pulp using water at temperatures between 200 degrees C and 250 degrees C enhanced enzymatic hydrolysis . Maximum ethanol production (11.9 g/L) was obtained after pretreating pulp at 210 degrees C in a SSF fed-batch procedure . Maximum hydroxytyrosol recovery was obtained in the liquid fraction when pretreated at 230 degrees C. Appl Biochem Biotechnol, 2002 Spring, 98-100, 699 - 716 Comparison of the fermentability of enzymatic hydrolyzates of sugarcane bagasse pretreated by steam explosion using different impregnating agents; Martin C et al.; Sugarcane bagasse is a potential lignocellulosic feedstock for ethanol production, since it is cheap, readily available, and has a high carbohydrate content . In this work, bagasse was subjected to steam explosion pretreatment with different impregnation conditions . Three parallel pretreatments were carried out, one without any impregnation, a second with sulfur dioxide, and a third with sulfuric acid as the impregnating agent . The pretreatments were performed at 205 degrees C for 10 min . The pretreated material was then hydrolyzed using cellulolytic enzymes . The chemical composition of the hydrolyzates was analyzed . The highest yields of xylose (16.2 g/100 g dry bagasse), arabinose (1.5 g/100 g), and total sugar (52.9 g/100 g) were obtained in the hydrolysis of the SO2 -impregnated bagasse . The H2SO4 -impregnated bagasse gave the highest glucose yield (35.9 g/100 g) but the lowest total sugar yield (42.3 g/100 g) among the three methods . The low total sugar yield from the H2SO4-impregnated bagasse was largely due to by-product formation, as the dehydration of xylose to furfural . Sulfuric acid impregnation led to a three-fold increase in the concentration of the fermentation inhibitors furfural and 5-hydroxymethylfurfural (HMF) and a two-fold increase in the concentration of inhibitory aliphatic acids (formic, acetic, and levulinic acids) compared to the other two pretreatment methods . The total content of phenolic compounds was not strongly affected by the different pretreatment methods, but the quantities of separate phenolic compounds were widely different in the hydrolyzate from the H2SO4-impregnated bagasse compared with the other two hydrolyzates . No major differences in the content of inhibitors were observed in the hydrolyzates obtained from SO2-impregnated and non-impregnated bagasse . The fermentability of all three hydrolyzates was tested with a xylose-utilizing Saccharomyces cerevisiae strain with and without nutrient supplementation . The hydrolyzates of SO2-impregnated and nonimpregnated bagasse showed similar fermentability, whereas the hydrolyzate of H2SO4-impregnated bagasse fermented considerably poorer. Appl Biochem Biotechnol, 2002 Spring, 98-100, 663 - 77 Growth of lignocellulosic-fermenting fungi on different substrates under low oxygenation conditions; Pavarina EC et al.; Four soil fungi able to grow under low oxygenation conditions were selected and used in studies to determine the production of enzymes that promote the degradation of lignocellulosic materials . The capacity of these fungi to ferment such materials was also investigated . The fungi were grown in sugarcane bagasse and sawdust at final concentrations of 4 and 10%, as the carbon sources . The strains were cultivated under microaerophilic and combined conditions of oxygenation (aerobic followed by microaerophilic conditions) . The results obtained with the basidiomycete specie, Trichocladium canadense, Geotrichum sp., and Fusarium sp . suggest that they prefer lower oxygen concentration for growth and enzyme production . Lignocellulolytic activities were detected in all strains but varied with the carbon source used . The highest levels of these activities were produced by the Basidiomycete specie and Fusarium sp . Ethanol and other nongaseous fermentation products were detected following high-performance liquid chromatography analysis using a supelcogel C-610H column, demonstrating the fermentative capability of these strains . In view of their ability to produce enzymes necessary for the breakdown of lignocellulosic materials and to utilize most of the degradation products for growth, these strains have a great potential for biotechnological application. Appl Biochem Biotechnol, 2002 Spring, 98-100, 599 - 610 Pressure pulsation in solid-phase fermentation; Yang X et al.; Inadequate dissipation of heat generated by biologic activities has prevented the use of solid-phase fermentation in large-scale applications . This study deals with the cooling effects of pressure pulsation on solid, porous beds . Pressure pulsation also enhances evaporation of medium moisture, which is also described . Computer software has been developed for on-line control of heat accumulation and moisture loss involving automatic variation in pressure pulsation frequency and airflow direction as well as replenishment of water . Aspergillus niger NRRL3 was cultivated on a moist, solid medium made of wheat bran and ground corncobs to produce cellobiase . During 100 h of fermentation, the maximum temperature inside the solid bed was kept under 40 degrees C, and the medium water content was successfully maintained between 61 and 65%, which was optimal for cell growth . Cells grew heavily on the solid-phase substrate and distributed uniformly . With good on-line control of temperature and moisture, the 12-L fermentor provided a better environment for enzyme production than 250 mL flasks did. Appl Biochem Biotechnol, 2002 Spring, 98-100, 59 - 72 SO2-catalyzed steam explosion of corn fiber for ethanol production; Bura R et al.; Corn fiber, a by-product of the corn wet-milling industry, represents a renewable resource that is readily available in significant quantities and could potentially serve as a low-cost feedstock for the production of fuel-grade alcohol . In this study, we used a batch reactor to steam explode corn fiber at various degrees of severity to evaluate the potential of using this feedstock in the bioconversion process . The results indicated that maximum sugar yields (soluble and following enzymatic hydrolysis) were recovered from corn fiber that was pretreated at 190 degrees C for 5 min with 6% SO2 . Sequential SO2-catalyzed steam explosion and enzymatic hydrolysis resulted in very high conversion (81%) of all polysaccharides in the corn fiber to monomeric sugars . Subsequently, Saccharomyces cerevisiae was able to convert the resultant corn fiber hydrolysates to ethanol very efficiently, yielding 90-96% of theoretical conversion during the fermentation process. Appl Biochem Biotechnol, 2002 Spring, 98-100, 563 - 75 Treatment with lignin residue: a novel method for detoxification of lignocellulose hydrolysates; Bjorklund L et al.; Acid hydrolysis of lignocellulose to hydrolysates intended for production of fuel ethanol results in the formation of byproducts in addition to fermentable sugars . Some of the byproducts, such as phenolic compounds and furan aldehydes, are inhibitory to the fermenting microorganism . Detoxification of the hydrolysates may be necessary for production of ethanol at a satisfactory rate and yield . The lignin residue obtained after hydrolysis is a material with hydrophobic properties that is produced in large amounts as a byproduct within an ethanol production process based on lignocellulosic raw materials . We have explored the possibility of using this lignin residue for detoxification of spruce dilute-acid hydrolysates prior to fermentation with Saccharomyces cerevisiae . Three dilute-acid hydrolysates of spruce were treated with lignin residue, which in all cases resulted in improved fermentability in terms of productivity and yield of ethanol . The effect was improved by washing the lignin before treatment, by using larger amounts of lignin in the treatment, and by performing the treatment at low temperature . Treatment with the lignin residue removed up to 53% of the phenolic compounds and up to 68% of the furan aldehydes in a spruce dilute-acid hydrolysate . A larger fraction of furfural was removed compared to the less hydrophobic 5-hydroxymethylfurfural. Appl Biochem Biotechnol, 2002 Spring, 98-100, 509 - 23 Use of measurement uncertainty analysis to assess accuracy of carbon mass balance closure for a cellulase production process; Schell DJ et al.; Closing carbon mass balances is a critical and necessary step for verifying the performance of any conversion process . We developed a methodology for calculating carbon mass balance closures for a cellulase production process and then applied measurement uncertainty analysis to calculate 95% confidence limits to assess the accuracy of the results . Cellulase production experiments were conducted in 7-L fermentors using Trichoderma reesei grown on pure cellulose (Solka-floc), glucose, or lactose . All input and output carbon-containing streams were measured and carbon dioxide in the exhaust gas was quantified using a mass spectrometer . On Solka-floc, carbon mass balances ranged from 90 to 100% closure for the first 48 h but increased to 101 to 135% closure from 72 h to the end of the cultivation at 168 h . Carbon mass balance closures for soluble sugar substrates ranged from 92 to 127% over the entire course of the cultivations . The 95% confidence intervals (CIs) for carbon mass balance closure were typically +/-11 to 12 percentage points after 48 h of cultivation . Many of the carbon mass balance results did not bracket 100% closure within the 95% CIs . These results suggest that measurement problems with the experimental or analytical methods may exist . This work shows that uncertainty analysis can be a useful diagnostic tool for identifying measurement problems in complex biochemical systems. Appl Biochem Biotechnol, 2002 Spring, 98-100, 5 - 21 Two-step steam pretreatment of softwood with SO2 impregnation for ethanol production; Soderstrom J et al.; Two-step steam pretreatment of softwood was investigated with the aim of improving the enzymatic digestibility for ethanol production . In the first step, softwood was impregnated with SO2 and steam pretreated at different severities . The first step was performed at low severity to hydrolyze the hemicellulose and release the sugars into the solution . The combination of time and temperature that yielded the highest amount of hemicellulosic sugars in the solution was determined . In the second step, the washed solid material from the optimized first step was impregnated once more with SO2 and steam pretreated under more severe conditions to enhance the enzymatic digestibility . The investigated temperature range was between 180 and 220 degrees C, and the residence times were 2, 5 and 10 min . The effectiveness of pretreatment was assessed by both enzymatic hydrolysis of the solids and simultaneous saccharification and fermentation (SSF) of the whole slurry after the second pretreatment step, in the presence of antibiotics . For each pretreatment combination, the liquid fraction was fermented to determine any inhibiting effects . At low severity in the second pretreatment step, a high conversion of cellulose was obtained in the enzymatic hydrolysis step, and at a high severity a high conversion of cellulose was obtained in the second pretreatment step . This resulted in an overall yield of sugars that was nearly constant over a wide range of severity . Compared with the one-step steam pretreatment, the two-step steam pretreatment resulted in a higher yield of sugar and in a slightly higher yield of ethanol . The overall sugar yield, when assessed by enzymatic hydrolysis, reached 80% . In the SSF configuration, an overall ethanol yield of 69% was attained. Appl Biochem Biotechnol, 2002 Spring, 98-100, 49 - 58 Dilute-acid hydrolysis of sugarcane bagasse at varying conditions; Neureiter M et al.; Sugarcane bagasse, a byproduct of the cane sugar industry, is an abundant source of hemicellulose that could be hydrolyzed to yield a fermentation feedstock for the production of fuel ethanol and chemicals . The effects of sulfuric acid concentration, temperature, time, and dry matter concentration on hemicellulose hydrolysis were studied with a 20-L batch hydrolysis reactor using a statistical experimental design . Even at less severe conditions considerable amounts (>29%) of the hemicellulose fraction could be extracted . The percentage of soluble oligosaccharides becomes very low in experiments with high yields in monosaccharides, which indicates that the cellulose fraction is only slightly affected . For the sugar yields, acid concentration appears to be the most important parameter, while for the formation of sugar degradation products, temperature shows the highest impact . It could be demonstrated that the dry matter concentration in the reaction slurry has a negative effect on the xylose yield that can be compensated by higher concentrations of sulfuric acid owing to a positive interaction between acid concentration and dry matter contents. Appl Biochem Biotechnol, 2002 Spring, 98-100, 489 - 96 Use of immobilized Candida yeast cells for xylitol production from sugarcane bagasse hydrolysate: cell immobilization conditions; Carvalho W et al.; Candida guilliermondii cells were immobilized in Ca-alginate beads and used for xylitol production from concentrated sugarcane bagasse hydrolysate . A full factorial design was employed to determine whether variations in the immobilization conditions would have any effects on the beads, chemical stability and on the xylitol production rates . Duplicate fermentation runs were carried out in 125-mL Erlenmeyer flasks maintained in a rotatory shaker at 30 degrees C and 200 rpm for 72 h . Samples were periodically analyzed to monitor xylose and acetic acid consumption, xylitol production, free cell growth, and bead solubilization . Concentrations of sodium alginate at 20.0 g/L and calcium chloride at 11.0 g/L and bead curing time of 24 h represented the most appropriate immobilization conditions within the range of conditions tested. Appl Biochem Biotechnol, 2002 Spring, 98-100, 449 - 58 Influence of oxygen availability on cell growth and xylitol production by Candida guilliermondii; Faria LF et al.; Oxygen availability is the most important environmental parameter in the production of xylitol by yeasts, directly affecting yields and volumetric productivity . This work evaluated the cell behavior in fermentations carried out with different dissolved oxygen concentrations (0.5-30.0% of saturation), as well as a limited oxygen restriction (0% of saturation), at several oxygen volumetric transfer coefficients (12 < or = kLa < or = 70 h(-1)) . These experiments allowed us to establish the specific oxygen uptake rate limits to ensure high yields and volumetric productivity . When oxygen availability was limited, the specific oxygen uptake rate values were between 12 and 26 mg of O2/of g cell x h, resulting in a yield of 0.71 g of xylitol/xylose consumed, and 0.85 g/{L x h} for the volumetric productivity . According to the results, the effective control of the specific oxygen uptake rate makes it possible to establish complete control over this fermentative process, for both cell growth and xylitol production. Appl Biochem Biotechnol, 2002 Spring, 98-100, 403 - 13 Xylose reductase and xylitol dehydrogenase activities of Candida guilliermondii as a function of different treatments of sugarcane bagasse hemicellulosic hydrolysate employing experimental design; Alves LA et al.; The sugarcane bagasse hydrolysate, which is rich in xylose, can be used as culture medium for Candida guilliermondii in xylitol production . However, the hydrolysate obtained from bagasse by acid hydrolysis at 120 degrees C for 20 min has by-products (acetic acid and furfural, among others), which are toxic to the yeast over certain concentrations . So, the hydrolysate must be pretreated before using in fermentation . The pretreatment variables considered were: adsorption time (15,37.5, and 60 min), type of acid used (H2So4 and H3Po4), hydrolysate concentration (original, twofold, and fourfold concentrated), and active charcoal (0.5, 1.75 and 3.0%) . The suitability of the pretreatment was followed by measuring the xylose reductase (XR) and xylitol dehydrogenase (XD) activity of yeast grown in each treated hydrolysate . The response surface methodology (2(4) full factorial design with a centered face) indicated that the hydrolysate might be concentrated fourfold and the pH adjusted to 7.0 with CaO, followed by reduction to 5.5 with H3PO4 . After that it was treated with active charcoal (3.0%) by 60 min . This pretreated hydrolysate attained the high XR/XD ratio of 4.5. Appl Biochem Biotechnol, 2002 Spring, 98-100, 229 - 41 Enhanced formation of extracellular laccase activity by the white-rot fungus Trametes multicolor; Hess J et al.; The white-rot fungus Trametes multicolor MB 49 has been identified as an excellent producer of the industrially important enzyme laccase . The formation of extracellular laccase could be considerably stimulated by the addition of Cu(II) to a simple, glycerol-based culture medium . In this study, optimal concentrations of copper were found to be 0.5-1 mM, which were added during the growth phase of the fungus . Other medium components important for laccase production are the carbon and nitrogen sources employed . When using an optimized medium containing glycerol (40 g/L), peptone from meat (15 g/L), and MgSO4 x 7H2O and stimulating enzyme formation by the addition of 1.0 mM Cu, maximal laccase activities obtained in shake-flask cultures were approx 85 U/mL . These results, however, could not be scaled up to a laboratory fermentor cultivation . Laccase production by T . multicolor decreased considerably when the fungus was grown in a stirred-tank reactor, presumably because of damage of the mycelia caused by shear stress and/or changes in the morphology of the fungus. Appl Biochem Biotechnol, 2002 Spring, 98-100, 205 - 13 Effect of kLa on the production of glucose 6-phosphate dehydrogenase from Saccharomyces cerevisiae grown by fermentation process; Silva DP et al.; In a 5-L fermentor (NBS-MF 105), Saccharomyces cerevisiae (0.7 g/L) was inoculated into a liquid medium (pH 4.0) containing 17 g/L of glucose, 2.55 g/L of yeast extract, 4.25 g/L of peptone, 2.04 g/L of Na2HPO4 x 12H2O, 4.34 g/L of (NH4)2SO4 and 0.064 g/L of MgSO4 x 7H2O and aerobically cultivated at 35 degrees C for 22 h . Agitation and aeration were adjusted to attain initial kLa values of 15, 60, 135, and 230 h(-1) . The glucose 6-phosphate dehydrogenase (G6PDH) productivity (PrG6PDH) obtained for kLa values of 15, 60, 135, and 230 h(-1) was 10.6, 31.8, 30.3, and 23.3 U/({Lx h}), respectively, whereas the cell productivity (Pr(x)) for the same kLa values were 0.24, 0.69, 0.69, and 0.49 g/{L x h}, respectively . Thus, both events are coupled and depend on the dissolved oxygen in the medium. Appl Biochem Biotechnol, 2002 Spring, 98-100, 1161 - 72 Combined sedimentation and filtration process for cellulase recovery during hydrolysis of lignocellulosic biomass; Knutsen JS et al.; A combined sedimentation and ultrafiltration process was investigated for recovering cellulase enzymes during the hydrolysis of lignocellulosic biomass . Lignocellulosic particles larger than approx 50 microm in length were first removed via sedimentation using an inclined settler . Ultrafiltration was then used to retain the remaining lignocellulosic particles and the cellulose enzymes, while transmitting fermentable sugars and other small molecules . The permeate flux from the ultrafiltration step for a feed consisting of 0.22 w/v% cellulase is 64+/-5 L/m2-h, while that for a feed consisting of the settler overflow from a mixture 0.22 w/v% cellulase and 10 wt% lignocellulose fed to the settler is 130+/-20 L/m2-h . The higher permeate flux in the latter case is presumably due to binding of a portion of the cellulase enzymes to the lignocellulosic particles during hydrolysis and filtration, preventing the enzymes from fouling the membrane . A filter paper activity assay shows little loss in enzymatic activity throughout the combined sedimentation/ultrafiltration separation process. Appl Biochem Biotechnol, 2002 Spring, 98-100, 1105 - 14 Mixed submerged fermentation with two filamentous fungi for cellulolytic and xylanolytic enzyme production; Garcia-Kirchner O et al.; The efficient saccharification of lignocellulosic materials requires the cooperative actions of different cellulase enzyme activities: exoglucanase, endoglucanase, beta-glucosidase, and xylanase . Previous studies with the fungi strains Aureobasidium sp . CHTE-18, Penicillium sp . CH-TE-001, and Aspergillus terreus CH-TE-013, selected mainly because of their different cellulolytic and xylanolytic activities, have demonstrated the capacity of culture filtrates of cross-synergistic action in the saccharification of native sugarcane bagasse pith . In an attempt to improve the enzymatic hydrolysis of different cellulosic materials, we investigated a coculture fermentation with two of these strains to enhance the production of cellulases and xylanases . The 48-h batch experimental results showed that the mixed culture of Penicillium sp . CH-TE-001 and A . terreus CH-TE-013 produced culture filtrates with high protein content, cellulase (mainly beta-glucosidase), and xylanase activities compared with the individual culture of each strain . The same culture conditions were used in a simple medium with mineral salts, corn syrup liquor, and sugarcane bagasse pith as the sole carbon source with moderate shaking at 29 degrees C . Finally, we compared the effect of the cell-free culture filtrates obtained from the mixed and single fermentations on the saccharification of different kinds of cellulosic materials. Appl Biochem Biotechnol, 2002 Spring, 98-100, 1049 - 59 Oxygen uptake rate in production of xylitol by Candida guilliermondii with different aeration rates and initial xylose concentrations; Gimenes MA et al.; The global oxygen uptake rate (OUR) and specific oxygen uptake rates (SOUR) were determined for different values of the volumetric oxygen mass transfer coefficient (15, 43, and 108 h(-1)), and for varying initial xylose concentrations (50, 100, 150, and 200 g/L) in shaking flasks . The initial cell concentration was 4.0 g/L, and there was only significant growth in the fermentation with the highest oxygen availability . In this condition, OUR increased proportionally to cell growth, reaching maximum values from 2.1 to 2.5 g of O2/(L x h) in the stationary phase when the initial substrate concentration was raised from 50 to 200 g/L, respectively . SOUR showed different behavior, growing to a maximum value coinciding with the beginning of the exponential growth phase, after which point it decreased . The maximum SOUR values varied from 265 to 370 mg of O2/(g of cell x h), indicating the interdependence of this parameter and the substrate concentration . Although the volumetric productivity dropped slightly from 1.55 to 1.18 g of xylitol/(L x h), the strain producing capacity (Y(P/X)) rose from 9 to 20.6 g/g when the initial substrate concentration was increased from 50 to 200 g/L . As for the xylitol yield over xylose consumed (Y(P/S)), there was no significant variation, resulting in a mean value of 0.76 g/g . The results are of interest in establishing a strategy for controlling the dynamic oxygen supply to maximize volumetric productivity. Appl Biochem Biotechnol, 2002 Spring, 98-100, 1009 - 23 Hybrid neural modeling of bioprocesses using functional link networks; Harada LH et al.; The objective of this work was to develop a model for an extractive ethanol fermentation in a simple and rapid way . This model must be sufficiently reliable to be used for posterior optimization and control studies . A hybrid neural model was developed, combining mass and energy balances with neural networks, which describe the process kinetics . To determine the best model, two structures of neural networks were compared: the functional link networks and the feedforward neural networks . The two structures are shown to describe well the process kinetics, and the advantages of using the functional link networks are discussed. Nahrung, 2002 Apr, 46(2), 92 - 5 Effect of soaking, germination, cooking and fermentation on antinutritional factors in cowpeas; Ibrahim SS et al.; The present work deals with the study of efficacy of some treatments, namely soaking (in water and bicarbonate solution), ordinary and pressure cooking, germination and fermentation in reducing or removal of antinutritional factors usually present in cowpeas (protease inhibitors, tannins, phytic acid and flatus-producing oligosaccharides (raffinose and stachyose) . The results showed that long-time soaking (16 h) in bicarbonate solution caused remarkable reduction in the antinutritional factors . Pressure cooking was more effective than ordinary . Cooking pregerminated cowpeas was most effective . Fermentation completely removed trypsin inhibitor, oligosaccharides and reduced remarkably phytic acid . However, tannins noticeably increased. Nahrung, 2002 Apr, 46(2), 64 - 7 Effect of bottle colour and storage conditions on browning of orange wine; Selli S et al.; We investigated the effect of bottle colour, storage temperature and storage time on the browning of orange wine . Kozan orange variety was used for the production of wine . The fermentation was performed spontaneously at 20 degrees C . The wine was bottled in three differently coloured bottles: clear white, green and brown . Then each was divided into two parts: one part was stored at 13-14 degrees C in the cellar and the other at 23-26 degrees C in the laboratory for 150 days . During the storage, browning index and ascorbic acid content of the wines were measured at day 0, 75 and 150 . The results showed that the use of brown bottles and the short-time storage reduced the browning in orange wines, however, storage at two different temperatures did not significantly affect the browning index. Yao Xue Xue Bao, 1998 Jul, 33(7), 481 - 5 {Fibrinolytic properties and thrombolytic effect of a novel fibrinolytic enzyme from Streptomyces sp . Y405}; Wang M et al.; A novel protease (designated as SW-1) purified from the fermentation broth of Streptomyces sp . strain Y405 showed fibrinolytic activity . In vitro, on plasminogen-free fibrin plate which had been heated at 85 degrees C for 30 minutes to eliminate plasminogen, SW-1 showed the same fibrinolytic activity as the mixture of SW-1 and plasminogen . Without adding plasminogen into the fibrin clot tube SW-1 showed the same effect as with plasminogen (P > 0.05) . The results might indicate that SW-1 is a fibrinolytic enzyme which degrades fibrin directly, but not a plasminogen activator which degrades fibrin by activating plasminogen . SW-1 was found also to degrade fibrinogen . In vivo, the thrombolytic effect of SW-1 (4000 u.kg-1) on venous thrombus in rat was most remarkable versus that of control(P < 0.001), but was not divergent versus that of urokinase at the some dose(P > 0.05) . SW-1 was shown to enhance plasminogen and plasmin activity but did not show significant effect on endogenous t-PA or alpha 2-PI . SW-1 also caused decrease of fibrinogen level in plasma, indicating that it degrades the fibrin in thrombus and at the same time degrades the circulating fibrinogen to certain extent . The changes of these biochemical data demonstrated the thrombolytic properties of SW-1 in vivo. Appl Microbiol Biotechnol, 2002 May, 58(6), 761 - 6 Epub 2002 Mar 20. Xylanase production in solid state fermentation by Aspergillus niger mutant using statistical experimental designs; Park YS et al.; The initial moisture content, cultivation time, inoculum size and concentration of basal medium were optimized in solid state fermentation (SSF) for the production of xylanase by an Aspergillus niger mutant using statistical experimental designs . The cultivation time and concentration of basal medium were the most important factors affecting xylanase activity . An inoculum size of 5 x 10(5) spores/g, initial moisture content of 65%, cultivation time of 5 days and 10 times concentration of basal medium containing 50 times concentration of corn steep liquor were optimum for xylanase production in SSF . Under the optimized conditions, the activity and productivity of xylanase obtained after 5 days of fermentation were 5,071 IU/g of rice straw and 14,790 IU l(-1) h(-1), respectively . The xylanase activity predicted by a polynomial model was 5,484 IU/g of rice straw. Appl Microbiol Biotechnol, 2002 May, 58(6), 735 - 42 Epub 2002 Mar 20. A theoretical analysis of the biosynthesis of actinorhodin in a hyper-producing Streptomyces lividansstrain cultivated on various carbon sources; Bruheim P et al.; A stoichiometric equation for the biosynthesis of actinorhodin (ACT) was derived taking into consideration both the requirements of the carbon precursors (acetyl-CoA) and reducing power (NADPH) . The estimate for reducing power was derived from a detailed molecular analysis of each step in the ACT biosynthetic pathway . Even though ACT is slightly more oxidized than most carbon substrates, e.g . glucose, reducing power (NADPH and NADH) is necessary due to reducing steps and to monooxygenase steps . The equation was used to evaluate, in a metabolic network context, the experimental results from batch fermentations with eight different carbon sources using a Streptomyces lividans 1326 derived strain containing the pathway-specific activator gene ( actII-ORF4) on a multicopy plasmid (pIJ68) . The yield of ACT on the various carbon sources ranged from 0.04 to 0.18 Cmol ACT/Cmol carbon source in the stationary phase . Glucose was the best carbon source and supported a yield of 25% of the maximum theoretical yield . There are no obvious constraints in the primary metabolic pathways that can explain why the various carbon sources allowed different levels of ACT production, because their potential for supplying acetyl-CoA and NADPH are far from fully utilized . For the observed ACT yields, there is an excess production of NADPH that has to be reoxidized either by a transhydrogenase or a NADPH oxidase . This study discusses the central metabolic pathways, focusing on providing precursors for ACT synthesis. Comp Biochem Physiol A Mol Integr Physiol, 2002 Jun, 132(2), 333 - 40 Production of short-chain fatty acids and gas from various oligosaccharides by gut microbes of carp (Cyprinus carpio L.) in micro-scale batch culture; Kihara M et al.; We studied the metabolism of various oligosaccharides by carp (Cyprinus carpio) hindgut microbes by measuring gas productivity and organic acid production in gut contents using a 50-microl-scale batch culture system . Carp hindgut contents were incubated with 500 microg each of raffinose, lactosucrose, kestose, lactulose, gentiobiose, 4'-galactosyllactose and 6'-galactosyllactose and soybean-, xylo-, and isomalto-oligosaccharides or none (blank culture) at 25 degrees C for 6 h . The time-course of gas release from the culture (Y microl/culture) was expressed as an exponential function of incubation time (t) {Y=A+Bx(1-e(-kt))}; A, B and k are constants) . Potential production of gas (A+B) from soybean-oligosaccharide and raffinose was larger than for the other saccharides except for kestose, and blank culture . The rate constant of gas (k) for lactosucrose was larger than that for isomalto- and xylo-oligosaccharide, lactulose, kestose or blank culture . Net production of total SCFA (sum of acetic, propionic and n-butyric acid weights) from cultures with soybean- and isomalto-oligosaccharides, raffinose, gentiobiose and lactosucrose was greater than that from blank culture . These results suggested that soybean-oligosaccharide and raffinose were potentially highly fermentable oligosaccharides for carp hindgut microbes . Chemical structures of oligosaccharides seem to play an important role in the fermentability . It is also likely that oligosaccharide utilization differs between mammals and teleosts. J Vet Med A Physiol Pathol Clin Med, 2002 Apr, 49(3), 157 - 60 Studies on the pH value of abomasal contents in dairy cows during the first 3 weeks after calving; Van Winden SC et al.; The pH value of the abomasal contents in adult cattle is normally constant and has a value of 2 . Abomasal contents with pH values of 5.5 and higher could give rise to bacterial fermentation with subsequent gas production . The accumulation of gas is thought to form a key event in the pathogenesis of abomasal displacement . The aim of the present study was to determine the pH values of abomasal contents of dairy cows in the first 3 weeks after calving . The pH of the abomasal contents was, over several days . higher than the pH value of the abomasal juice in mid-lactation cows . The highest pH values were measured on day 14 after calving, thereafter the pH declined . Possible explanations for the rise in the pH value of the abomasal contents are discussed. J Vet Med A Physiol Pathol Clin Med, 2002 Apr, 49(3), 151 - 6 Bile acid extraction rate in the liver of cows fed high-fat diet and lipid profiles in the portal and hepatic veins; Mohamed T et al.; The purposes of this study are to assess the responses of increased supplemental dietary fat in the cow, without upsetting rumen fermentation, on the bile acid (BA) extraction rate in the liver and to determine whether this diet would affect the postprandial lipid profiles in the portal and hepatic venous blood . Six Holstein cows were equipped with catheters fitted in the portal and hepatic veins . Two cows each were assigned randomly to a sequence of three dietary treatments of 21-day period . The methodology of this study was based on the supplementation of the basal concentrate diet with 0 (control), 5, or 10% calcium salts of fatty acids (CSFA) . The total bile acids were significantly increased in the portal and hepatic veins with the 5% CSFA diet, whereas no increase occurred with the 10% CSFA diet . Data obtained in this study showed that 10% CSFA diet failed to stimulate BA secretion to exceed the values obtained with 5% CSFA-diet . Moreover, there was no change in the hepatic extraction rate of BA in animals fed either the 0 or 5% CSFA diets which ranged from 2.4 to 6.5-fold and 3.1 to 7.3-fold, respectively . However, the extraction rate increased sharply with the 10% CSFA diet (27-fold) . The median portal and hepatic concentrations of total lipids, triglycerides, total cholesterol, phospholipids and non-esterified fatty acids did not show any significant increase during feeding of the control diet . Moreover, feeding either the 5 or 10% CSFA diet did not significantly increase these values in either vein. Indian J Exp Biol, 2001 Jul, 39(7), 691 - 6 Gluconic acid production by Aspergillus niger mutant ORS-4.410 in submerged and solid state surface fermentation; Singh OV et al.; Aspergillus niger ORS-4.410, a mutant of Aspergillus niger ORS-4 was produced by repeated irradiation with UV rays . Treatments with chemical mutagnes also resulted into mutant strains . The mutants differed from the parent strain morphologically and in gluconic acid production . The relationship between UV treatment dosage, conidial survival and frequency of mutation showed the maximum frequency of positive mutants (25%) was obtained along with a conidial survival of 59% after second stage of UV irradiation . Comparison of gluconic acid production of the parent and mutant ORS-4.410 strain showed a significant increase in gluconic acid production that was 87% higher than the wild type strain . ORS-4.410 strain when transferred every 15 days and monitored for gluconic acid levels for a total period of ten months appeared stable . Mutant ORS-4.410 at 12% substrate concentration resulted into significantly higher i.e . 85-87 and 94-97% yields of gluconic acid under submerged and solid state surface conditions respectively . Further increase in substrate concentration appeared inhibitory . Maximum yield of gluconic acid was obtained after 6 days under submerged condition and decreased on further cultivation . Solid state surface culture condition on the other hand resulted into higher yield after 12 days of cultivation and similar levels of yields continued thereafter. J Anim Sci, 2002 May, 80(5), 1223 - 32 Isolated canine and murine intestinal cells exhibit a different pattern of fuel utilization for oxidative metabolism; Beaulieu AD et al.; The amount and type of dietary fiber influences the end-products of fermentation and thus fuel availability to intestinal tissue . Metabolic fuel usage was studied in intestinal cells isolated from dogs consuming a commercial diet or from rats consuming either a commercial rat diet or dog diet to examine preferential fuel usage, the effect of diet, and species differences . Production of 14CO2 was measured by incubating cells in media containing either D-{U-14C}glucose, {1-14C}n-butyrate, L-{U-14C}glutamine, or {1-14C}propionate with or without competing substrates . The presence of a mixture of 5 mM each of glucose, butyrate, propionate, and acetate and 1 mM glutamine in the media decreased CO2 production from glucose, glutamine, and propionate by canine enterocytes (P < 0.05) and from glutamine and propionate by canine colonocytes (P < 0.05) . The presence of glutamine in the media decreased glucose oxidation by murine enterocytes, regardless of the diet . Similarly, glutamine decreased glucose oxidation by murine colonocytes (P < 0.05), but only when the rats had consumed the rat diet . Regardless of diet, murine colonocytes oxidized more butyrate (P < 0.01) than did enterocytes, and murine enterocytes tended (P < 0.07) to oxidize more glucose than did colonocytes . The proportion of propionate in colonic contents was higher in dogs than in rats (P < 0.02), and the proportion of butyrate tended to be higher in contents from rats than in those from dogs (P < 0.08) . Colonic and cecal wet weights were decreased (P < 0.05) when rats were fed the commercial dog diet . Preferred utilization of substrates by isolated canine enterocytes and colonocytes differed from that of murine intestinal cells . These differences were only partially overcome by feeding the same diet to each species. J Anim Sci, 2002 May, 80(5), 1179 - 86 Fermented wheat in liquid diets: effects on gastrointestinal characteristics in weanling piglets; Scholten RH et al.; Effects of adding fermented wheat to liquid diets on gastrointestinal characteristics in weanling piglets were studied . Gastrointestinal characteristics of 40 28-d-old weanling piglets were measured at the day of weaning (d 0) and at d 4 and 8 after weaning . Piglets were group-housed and fed twice daily . Feeding level was based on the average metabolic BW of piglets per group . Groups were fed a liquid diet with either 45% unfermented wheat (FERM_0) or 45% fermented wheat (FERM_45) . The other 55% of the diet was identical . To ferment wheat, water at 30 degrees C was added to milled wheat in a 1:2.2 ratio . The pH and contents of lactic acid, acetic acid, propionic acid, and butyric acid were measured in the digesta of the stomach, three parts of the small intestine, cecum, and large intestine . In addition, changes in microbial populations in the digesta were studied during the period after weaning . Moreover, villus height, crypt depth, and villus shape were studied in the small intestine . Piglets fed FERM_45 showed lower gastric pH (P < 0.05) at d 4 and higher gastric lactic acid content (P < 0.001) at both d 4 and 8 . Piglets fed FERM_45 showed in the first part of the small intestine higher villus height (P < 0.01) at d 8 and higher villus:crypt ratio (P < 0.001) at both d 4 and 8 . Villus shape tended (P < 0.10) to be favorable for piglets fed FERM_45 . The present study indicates that feeding a partly fermented liquid diet to weanling piglets may be a concept to prevent undesirable changes in mucosal architecture after weaning. J Antibiot (Tokyo), 2002 Mar, 55(3), 249 - 55 Watasemycins A and B, new antibiotics produced by Streptomyces sp . TP-A0597; Sasaki O et al.; Two novel antibiotics, watasemycins A and B, were isolated from the fermentation broth of an actinomycete strain . The producing strain TP-A0597 was isolated from the seawater sample collected in Toyama Bay, Japan and identified as Streptomyces sp . based on the taxonomic study . The new antibiotics were obtained by solvent extraction and chromatographic purification and spectroscopic analyses identified that they were new analogs of thiazostatins . Watasemycin possesses a methyl group at 5'-position of thiazostatin instead of a hydrogen atom . Watasemycins showed antibiotic activity against Gram-positive and negative bacteria and yeast. J Antibiot (Tokyo), 2002 Mar, 55(3), 239 - 48 Novel stachyflin derivatives from Stachybotrys sp . RF-7260 . Fermentation, isolation, structure elucidation and biological activities; Minagawa K et al.; Stachybotrys sp . RF-7260 was found to produce stachyflins, novel anti-influenza virus agents, under solid-state fermentation conditions . Feeding DL-lysine to a culture of Stachybotrys sp . RF-7260 induced the formation of the novel compounds, SQ-02-S-L2 and -L1, and feeding DL-valine the formation of SQ-02-S-VI and -V2 . The structures of these metabolites were determined by detailed 2D NMR analyses in comparison with acetylstachyflin . SQ-02-S-L2 and -L1 have the lysine moiety and SQ-02-S-V1 has the valine moiety . SQ-02-S-V2 has an amidine moiety instead of the lactam moiety in acetylstachyflin . SQ-02-S-L2, -L1 and -V1, substituted on the lactam amide hydrogen, displayed only a low level of the antiviral activity . However, deacetyl SQ-02-S-V2 showed potent antiviral activity similar to stachyflin. Extremophiles, 2002 Apr, 6(2), 161 - 6 Effect of glucose, maltose, soluble starch, and CO2 on the growth of the hyperthermophilic archaeon Pyrococcus furiosus; Biller KF et al.; The hyperthermophilic archaeon Pyrococcus furiosus was cultivated in batch and continuous fermentations on different carbon substrates . The cultivation of P furiosus on soluble starch as the only carbon source resulted in cell densities three times higher than in cultivations on maltose, 1.06 x 10(10) cells/ml compared to 3.4 x 10(9) cells/ml . The yield coefficient, Y(x/y) = 0.12 g/g, and the growth rate, mu = 0.33 h(-1), were almost equal on soluble starch and on maltose, but on glucose no growth could be detected . An inhibitory effect of glucose, when added to other carbon substrates, also could not be found . Isobutyric and isovaleric acid were detected as novel metabolites produced by P . furiosus . Inhibitory effects of these acids, as well as of the well-known products acetic acid, propionic acid, and alanine, could be precluded . Concentrations of 10% CO2 in the gas supply respective to the exhaust gas enhanced the growth of P furiosus significantly . The maximum cell number was two orders of magnitude higher than was observed with pure nitrogen . Further increase of the CO2 concentration up to 100% had no significant effect on the growth of P . furiosus. J Chromatogr B Analyt Technol Biomed Life Sci, 2002 Apr 25, 770(1-2), 255 - 9 A simple, optimized method for the determination of sulphide in whole blood by GC-mS as a marker of bowel fermentation processes; Hyspler R et al.; Hydrogen sulphide is produced in human large intestine by anaerobic fermentation and may play a pathogenic role . An analytical method for determination of sulphide in whole blood using an extractive alkylation technique was optimised and validated for this purpose . The sample was mixed with organic phase containing pentafluorobenzyl bromide as an alkylating agent . The benzalkonium chloride was used as a phase-transfer catalyst . The quantitative determination was performed using GC-MS technique in selected ion monitoring mode . The blood levels of sulphide of healthy controls were measured (35-80 microM/l) . The method is versatile, reproducible (RSD=2.7%) and suitable for research of anaerobic fermentation in vivo. Infect Immun, 2002 Jun, 70(6), 3101 - 10 Purification, characterization, and immunogenicity of the refolded ectodomain of the Plasmodium falciparum apical membrane antigen 1 expressed in Escherichia coli; Dutta S et al.; The apical membrane antigen 1 (AMA1) has emerged as a promising vaccine candidate against malaria . Advanced evaluation of its protective efficacy in humans requires the production of highly purified and correctly folded protein . We describe here a process for the expression, fermentation, refolding, and purification of the recombinant ectodomain of AMA1 (amino acids 83(Gly) to 531(Glu)) of Plasmodium falciparum (3D7) produced in Escherichia coli . A synthetic gene containing an E . coli codon bias was cloned into a modified pET32 plasmid, and the recombinant protein was produced by using a redox-modified E . coli strain, Origami (DE3) . A purification process was developed that included Sarkosyl extraction followed by affinity purification on a Ni-nitrilotriacetic acid column . The recombinant AMA1 was refolded in the presence of reduced and oxidized glutathione and further purified by using two ion-exchange chromatographic steps . The final product, designated AMA1/E, was homogeneous, monomeric, and >99% pure and had low endotoxin content and low host cell contamination . Analysis of AMA1/E showed that it had the predicted primary sequence, and tertiary structure analysis confirmed its compact disulfide-bonded nature . Rabbit antibodies made to the protein recognized the native parasite AMA1 and inhibited the growth of the P . falciparum homologous 3D7 clone in an in vitro assay . Reduction-sensitive epitopes on AMA1/E were shown to be necessary for the production of inhibitory anti-AMA1 antibodies . AMA1/E was recognized by a conformation-dependent, growth-inhibitory monoclonal antibody, 4G2dc1 . The process described here was successfully scaled up to produce AMA1/E protein under GMP conditions, and the product was found to induce highly inhibitory antibodies in rabbits. Br J Nutr, 2002 May, 87(5), 421 - 6 A modified dot-blot method of protein determination applied in the tannin-protein precipitation assay to facilitate the evaluation of tannin activity in animal feeds; Hoffmann EM et al.; Tannins have received considerable attention from animal nutritionists as potential agents for modifying ruminal fermentation patterns, or for exploring new feed resources . This group of secondary plant compounds is defined by their ability to form complexes with proteins . A widely accepted method for assaying the biological activity of extracted tannins is the precipitation of bovine serum albumin . The protein carries a radioactive label (125I) to allow direct quantification from the precipitate . Tannin-protein complexes dissolve in sodium dodecylsulfate solution . A dot-blot assay for protein determination, which is based on the reversible binding of a fluorochrome, benzoxanthene yellow, to the protein spots and is not disturbed by the presence of detergents, can replace the radioactive method by a fluorimetric measurement . A novel alternative to the last part of the dot-blot assay is to scan the stained protein spots in situ using a video camera and computer image analysis . Several filter sets were tested and, within a concentration range of 0.1-2.0 mg protein/ml, each of them yielded results identical to the original method while the time required was only 30 % of the working time consumed by the original procedure . The modified dot-blot assay should be applicable to the evaluation of tannin activity in all shrub and tree foliages considered as animal feed. Physiol Plant, 2002 May, 115(1), 119 - 124 Ethanol sensitivity of rice and oat coleoptiles; Kato-Noguchi H; The ability to avoid the ethanol-induced injury was evaluated in rice (Oryza sativa L.) and oat (Avena sativa L.) coleoptiles . The growth of the rice and oat coleoptiles was inhibited by ethanol exogenously applied at concentrations greater than 200 and 30 mM, respectively . At 300 mM ethanol, oat coleoptiles were brown and flaccid but rice coleoptiles did not show any visible symptoms of toxicity . The acetaldehyde level in rice and oat coleoptiles was increased by exogenously applied ethanol and the increases were greater in oat than in rice coleoptiles under aerobic and anaerobic conditions . At 300 mM ethanol, the acetaldehyde concentrations in the rice and oat coleoptiles were 46 and 87 nmol g-1 FW under aerobic conditions, respectively, and 52 and 124 nmol g-1 FW under anaerobic conditions, respectively . The activity of alcohol dehydrogenase (ADH; EC 1.1.1.1) in the direction of ethanol to acetaldehyde was greater in oat than in rice coleoptiles and ADH protein in oat coleoptiles was more induced by exogenously applied ethanol than that in rice coleoptiles . These results suggest that in vivo conversion rate of ethanol to acetaldehyde by ADH is lower in rice than oat coleoptiles, which may be one of the reasons that ethanol sensitivity of rice is much lower than that of oat coleoptiles . The great ability of rice to avoid the ethanol-induced injuries may contribute its anoxia tolerance when glycolysis and ethanolic fermentation replace the Krebs cycle as the main source of energy under anaerobic conditions. J Agric Food Chem, 2002 May 22, 50(11), 3277 - 82 Impact odorants contributing to the fungus type aroma from grape berries contaminated by powdery mildew (Uncinula necator); incidence of enzymatic activities of the yeast Saccharomyces cerevisiae; Darriet P et al.; Powdery mildew due to the fungus Uncinula necator is an important disease for the vineyard . The development of the fungus at the surface of the berries leads to the occurrence of a very characteristic and sometimes intense mushroom-type odor cited as an important default for grapes quality . Gas chromatography/olfactometry, gas chromatography, and multidimensional gas chromatogaphy/mass spectrometry techniques were used to investigate the most important odorants of grapes diseased by powdery mildew . Among 22 odorants detected, strongly odorant compounds were identified or tentatively identified in purified extracts obtained from grapes diseased by powdery mildew . Aroma extraction dilution analysis (AEDA) analysis revealed that 1-octen-3-one (mushroom odor), (Z)-1,5-octadien-3-one (geranium-leaf odor), and an unidentified odorous zone (fishy-mushroom like odor) were the most potent volatiles of the diseased grapes . In the presence of nonproliferating Saccharomyces cerevisiae yeast cells, and consequently during alcoholic fermentation, the enzymatic reduction of 1-octen-3-one and (Z)-1,5-octadien-3-one to much less odorant compounds, namely 3-octanone and (Z)-5-octen-3-one, was shown . Those results explain to some extent the disappearance of the fungal aroma specific to powdery mildew grapes during alcoholic fermentation. J Agric Food Chem, 2002 May 22, 50(11), 3186 - 92 Ellagic acid and flavonoid antioxidant content of muscadine wine and juice; Talcott ST et al.; Antioxidant properties of flavonoids and ellagic acid were characterized in eight wines and juices produced by various processing methodologies from red and white muscadine grape cultivars (Vitis rotundifolia) . Juices and wines were produced by hot- and cold-pressed techniques, and additional wine was produced following on-hull fermentation for 3, 5, and 7 days . Chromatographic conditions were developed to simultaneously separate anthocyanins, ellagic acid, and flavonols and correlated to a measurement of overall antioxidant capacity (AOX), and their changes were monitored after storage for 60 days at 20 and 37 degrees C . Regression coefficients between concentrations of individual polyphenolics and AOX ranged from 0.55 for ellagic acid to 0.90 for kaempferol . Both red and white wines had higher AOX values after storage than juices made from an identical grape press, despite lower concentrations of individual polyphenolic compounds . Red wines fermented on-hull had higher initial concentrations of antioxidant polyphenolics as compared to a corresponding hot-pressed juice, but changes in AOX during storage were more affected by time than by storage temperature despite lower concentrations of flavonoids and ellagic acid present at 37 degrees C as compared to 20 degrees C . Oxidative or polymerization reactions significantly decreased levels of monomeric anthocyanins during storage with the greatest losses observed for delphinidin and petunidin 3,5-diglucosides . Processing methods for muscadine wine and juice production were important factors influencing concentrations of antioxidant flavonoids and ellagic acid, while the role of fermentation and time had the greatest influence on retention of AOX properties during storage. Metab Eng, 2002 Apr, 4(2), 182 - 92 Metabolic engineering through cofactor manipulation and its effects on metabolic flux redistribution in Escherichia coli; San KY et al.; Applications of genetic engineering or metabolic engineering have increased in both academic and industrial institutions . Most current metabolic engineering studies have focused on enzyme levels and on the effect of the amplification, addition, or deletion of a particular pathway . Although it is generally known that cofactors play a major role in the production of different fermentation products, their role has not been thoroughly and systematically studied . It is conceivable that in cofactor-dependent production systems, cofactor availability and the proportion of cofactor in the active form may play an important role in dictating the overall process yield . Hence, the manipulation of these cofactor levels may be crucial in order to further increase production . We have demonstrated that manipulation of cofactors can be achieved by external and genetic means and these manipulations have the potential to be used as an additional tool to achieve desired metabolic goals . We have shown experimentally that the NADH/NAD(+) ratio can be altered by using carbon sources with different oxidation states . We have shown further that the metabolite distribution can be influenced by a change in the NADH/NAD(+) ratio as mediated by the oxidation state of the carbon source used . We have also demonstrated that the total NAD(H/(+)) levels can be increased by the overexpression of the pncB gene . The increase in the total NAD(H/(+)) levels can be achieved even in a complex medium, which is commonly used by most industrial processes . Finally, we have shown that manipulation of the CoA pool/flux can be used to increase the productivity of a model product, isoamyl acetate. Bioelectrochemistry, 2002 May 15, 56(1-2), 127 - 9 Monitoring of ethanol during fermentation using a microbial biosensor with enhanced selectivity; Tkac J et al.; The present study is concerning the construction of ferricyanide-mediated Gluconobacter oxydans cell ethanol biosensor . The size exclusion effect of a cellulose acetate membrane was used for elimination of glucose interferences during ethanol assays in real samples . A typical response time of the biosensor was 13 s with a high sensitivity of 3.5 microA mM(-1) . The microbial biosensor exhibits a very low detection limit of 0.85 microM and a wide linear range from 2 to 270 microM . The operational stability was excellent . During 8.5 h of repetitive ethanol assays, no decrease in the sensor sensitivity was observed . The biosensor was successfully used in the off-line monitoring of ethanol fermentation with a good agreement with HPLC measurements (R(2)=0.998). Int J Biochem Cell Biol, 2002 Aug, 34(8), 901 - 6 A lipoprotein family from Mycoplasma fermentans confers host immune activation through Toll-like receptor 2; Seya T et al.; Mycoplasma have been reported to be associated with human diseases . Three forms of a mycoplasma lipopeptide/protein with the ability to modulate the host immune system were independently identified and named macrophage-activating lipopeptide 2 (MALP-2), P48 and M161Ag (identical to MALP-404) . Although these molecules had polypeptides of different sizes, they exerted similar immunomodulatory effects on macrophages/dendritic cells, such as cytokine induction, NO production and maturation of antigen-presenting cells (APCs) . M161Ag exhibited complement-activating ability and bound macrophages via complement C3b/C3bi and their receptors . The diacylated N-terminal palmitates were involved in these activities . Toll-like receptor 2 (TLR2) was found to be responsible for these functional features of these mycoplasma products, except for complement activation . Here, we summarize the functional properties of this family of proteins, namely pathogen-associated molecular pattern (PAMP) and discuss its relationship to the reported pathogenesis of latent mycoplasma infection. Trends Biotechnol, 2002 Jun, 20(6), 257 - 60 Impact of targeted vector design on Co/E1 plasmid replication; Grabherr R et al.; The demands for recombinant proteins, in addition to plasmid DNA, for therapeutic use are steadily increasing . Bacterial fermentation processes have long been and still are the major tool for production of these molecules . The key objective of process optimization is to attain a high yield of the required quality, which is determined, to a large extent, by plasmid replication rates, metabolic capacity and the properties of the specific gene construct . When high copy number plasmids are used, the metabolic capacity of the host cell is often overstrained and efficient protein production is impaired . The plasmid copy number is the key parameter in the exploitation of the host cell, and can be maximized by optimal control of the flux ratios between biosynthesis of host cell proteins and recombinant proteins. Bioresour Technol, 2002 Apr, 82(2), 171 - 6 Effect of temperature, anaerobiosis, stirring and salt addition on natural fermentation silage of sardine and sardine wastes in sugarcane molasses; Zahar M et al.; Conditions for a natural fermentation during ensilage of sardines or their waste in sugarcane molasses (60:40 w/w) were evaluated regarding the effect of temperature (15, 25 and 35 degrees C), anaerobiosis (closed vs . open jars), daily stirring of the mixture, and salt addition to the initial mix at 5% (w/w) level . Successful natural fermentation took place in sardine silages incubated at 25 or 35 degrees C in open jars to reach a pH of 4.4 in about 2 and 1 weeks, respectively . For samples kept at 15 degrees C, the pH decline was very slow and pH did not decrease below 5.5 after one month of incubation . At 25 degrees C, the most favorable conditions for silage of sardine waste in cane molasses, as evidenced by the fastest decline in pH to a stable value of about 4.4, were achieved in closed jars and with daily stirring of the mix . The pH 4.4 was reached in one week with an advance of at least 3 days compared to the other conditions (open jars and closed jars without daily stirring) . Addition of salt at 5% (w/w) in the mix before incubation inhibited the fermentation process. Bioresour Technol, 2002 Apr, 82(2), 131 - 7 Bio-degradation of lignin in olive pomace by freshly-isolated species of Basidiomycete; Haddadin MS et al.; The solid waste (pomace) from olive oil processing cannot be used directly as an animal feed, but it was thought that an appropriate series of fermentations might improve its nutritional value . As a first step, typical samples of pomace were subjected, after an alkaline pre-treatment, to delignification by Phanerochaete chrysosporium (ATCC 19343), Oxysporus sp., Schizophyllum commune, Hyphoderma sp . or Ganoderma sp.; the last four species being freshly isolated from decaying wood collected in a woodland in Jordan . The relative activity of the species was judged by the levels of ligninase or laccase secreted and the extent of lignin degradation under a range of experimental conditions . Oxysporus sp . (ca . 69%) and S . commune (ca . 53%) gave significantly higher levels of breakdown of the lignified material than the other recent isolates . P . chrysosporium (ca . 60%) was not as active as in previously reported studies, and it may be that culturing the fungus on a standard laboratory medium had reduced its ability to generate ligninase . Further work is needed to establish whether the delignified pomace could be further processed into a feed for poultry. J Antibiot (Tokyo), 2002 Feb, 55(2), 155 - 64 Stachyflin and acetylstachyflin, novel anti-influenza A virus substances, produced by Stachybotrys sp . RF-7260 . I . Isolation, structure elucidation and biological activities; Minagawa K et al.; Two novel compounds, stachyflin and acetylstachyflin, have been isolated by solid-state fermentation of Stachybotrys sp . RF-7260 . The structures of both metabolites, determined by detailed NMR analyses and X-ray crystallographic analysis, are novel with a pentacyclic moiety including cis-fused decalin . The absolute stereochemistry of stachyflins was determined by circular dichroism analysis . Stachyflin showed antiviral activity against influenza A virus (H1N1) in vitro with an IC50 value of 0.003 microM . Acetylstachyflin was about 77-fold less active than stachyflin. J Antibiot (Tokyo), 2002 Feb, 55(2), 141 - 6 Migrastatin and a new compound, isomigrastatin, from Streptomyces platensis; Woo EJ et al.; Streptomyces platensis (strain NRRL 18993), a producer of dorrigocins, was shown to produce migrastatin, a cyclic congener of dorrigocin A previously reported from a different organism . Additionally a new compound isomeric to migrastatin, isomigrastatin, was also isolated and its structure was determined to be a cyclic form of dorrigocin B . Both compounds were fully characterized from MS and NMR data . Product titers of both were improved by the addition of XAD-16 resin to the fermentation medium. J Antibiot (Tokyo), 2002 Feb, 55(2), 121 - 7 CJ-21,164, a new D-glucose-6-phosphate phosphohydrolase inhibitor produced by a fungus Chloridium sp; Kim YJ et al.; A new D-glucose-6-phosphate phosphohydrolase (G6Pase) inhibitor, CJ-21,164 (1) was isolated from the fermentation broth of the fungus Chloridium sp . CL48903 . The structure was elucidated to be a novel tetramer of the salicylic acid derivatives by spectroscopic analyses . Compound I inhibited G6Pase in rat liver microsomes with an IC50 of 1.6 microM . Glucose output from hepatocytes isolated from rat liver was inhibited when I was present in the incubation medium, consistent with the role of I as a G6Pase inhibitor. Breast Cancer Res Treat, 2002 Feb, 71(3), 203 - 17 Chemopreventive and adjuvant therapeutic potential of pomegranate (Punica granatum) for human breast cancer; Kim ND et al.; Fresh organically grown pomegranates (Punica granatum L.) of the Wonderful cultivar were processed into three components: fermented juice, aqueous pericarp extract and cold-pressed or supercritical CO2-extracted seed oil . Exposure to additional solvents yielded polyphenol-rich fractions ('polyphenols') from each of the three components . Their actions, and of the crude whole oil and crude fermented and unfermented juice concentrate, were assessed in vitro for possible chemopreventive or adjuvant therapeutic potential in human breast cancer . The ability to effect a blockade of endogenous active estrogen biosynthesis was shown by polyphenols from fermented juice, pericarp, and oil, which inhibited aromatase activity by 60-80% . Fermented juice and pericarp polyphenols, and whole seed oil, inhibited 17-beta-hydroxysteroid dehydrogenase Type 1 from 34 to 79%, at concentrations ranging from 100 to 1,000 microg/ml according to seed oil >> fermented juice polyphenols > pericarp polyphenols . In a yeast estrogen screen (YES) lyophilized fresh pomegranate juice effected a 55% inhibition of the estrogenic activity of 17-beta-estradiol; whereas the lyophilized juice by itself displayed only minimal estrogenic action . Inhibition of cell lines by fermented juice and pericarp polyphenols was according to estrogen-dependent (MCF-7) >> estrogen-independent (MB-MDA-231) > normal human breast epithelial cells (MCF-10A) . In both MCF-7 and MB-MDA-231 cells, fermented pomegranate juice polyphenols consistently showed about twice the anti-proliferative effect as fresh pomegranate juice polyphenols . Pomegranate seed oil effected 90% inhibition of proliferation of MCF-7 at 100 microg/ml medium, 75% inhibition of invasion of MCF-7 across a Matrigel membrane at 10 microg/ml, and 54% apoptosis in MDA-MB-435 estrogen receptor negative metastatic human breast cancer cells at 50 microg/ml . In a murine mammary gland organ culture, fermented juice polyphenols effected 47% inhibition of cancerous lesion formation induced by the carcinogen 7,12-dimethylbenz{a}anthracene (DMBA) . The findings suggest that clinical trials to further assess chemopreventive and adjuvant therapeutic applications of pomegranate in human breast cancer may be warranted. J Anim Sci, 2002 Apr, 80(4), 1135 - 43 Effect of extruded full-fat soybeans on conjugated linoleic acid content of intramuscular, intermuscular, and subcutaneous fat in beef steers; Madron MS et al.; Crossbred Angus steers (n = 30) were used to determine whether the conjugated linoleic acid (CLA) content of beef fat could be increased by feeding varying levels of extruded full-fat soybeans as a source of polyunsaturated fatty acids for rumen biohydrogenation . Diets were as follows: 1) control, 2) 12.7% extruded full-fat soybeans (LESB), and 3) 25.6% extruded full-fat soybeans (HE SB) . Steers were individually housed and fed the diets for 111 d during the finishing period . Over the experimental period, treatment groups were similar in ADG (1.7 +/- 0.1 kg/d) and had a similar slaughter weight (603 +/- 11.6 kg) . Dressing percentage averaged 61.6% and carcass composition averaged 14.3% protein, 30.9% lipid, and 54.8% water . At slaughter, the intramuscular, intermuscular, and subcutaneous fat depots were sampled from the rib longissimus, eye of round, and chuck tender muscles . Across all fat depots, the CLA content differed (P < 0.05), averaging 6.6, 6.7, and 7.7 mg/g of fatty acids for the control, LESB, and HESB diets, respectively . There were significant differences in CLA content between fat depots within a cut, but differences were relatively small and the hierarchy in fat depots was not consistent among cuts . The cis-9, trans-11 isomer was the predominant CLA isomer and its content in fat was related to trans-11 C18:1 content (r = 0.53; P < 0.001) . There was substantial individual variation in CLA content and this varied from 2.6 to 17.0 mg/g fatty acids across all treatments and fat depots . Overall, results demonstrated that including extruded full-fat soybeans in the diet of finishing steers increased the CLA content of beef fat . Differences were relatively small and the relationship of this to rumen fermentation and endogenous synthesis of CLA is considered. J Anim Sci, 2002 Apr, 80(4), 1117 - 23 Carbohydrate fermentation and nitrogen metabolism of a finishing beef diet by ruminal microbes in continuous cultures as affected by ethoxyquin and(or) supplementation of monensin and tylosin; Han H et al.; Long-term feedlot studies have shown positive effects (i.e., improved ADG and reduced morbidity and mortality) of dietary supplementation with ethoxyquin (AGRADO) . This may be due to improving the antioxidant capacity at the ruminal, postruminal, or postabsorption levels . This study was designed to investigate the role of ethoxyquin at the rumen level . A finishing diet (12.5% CP; DM basis) was formulated to contain (on a DM basis) 77.5% flaked corn, 10% corn cobs, 10% protein/vitamin/mineral supplement, and 2.5% tallow . In a randomized complete block design experiment, the treatments were arranged as a 2 x 2 factorial . The main factors were two ethoxyquin treatments (without or with 150 ppm) and two monensin/tylosin treatments (without or with monensin and tylosin at 0.0028 and 0.0014% of dietary DM, respectively) . Eight dual-flow, continuous culture fermenters were used in two experimental periods (blocks; 8 d each with 5 d for adjustment and 3 d for sample collection) to allow for four replications for each treatment . No interactions (P > 0.05) were detected for any of the measurements evaluated . Therefore, results of the main factors were summarized . Ethoxyquin supplementation improved (P < 0.05) true digestibility of OM (from 38.8 to 45.0%) but it did not alter (P > 0.05) concentrations of total VFA (averaging 131 mM) or acetate (averaging 58.8 mM) . Ethoxyquin decreased (P < 0.05) propionate concentration from 51.1 to 42.4 mM and increased (P < 0.05) butyrate concentration from 18.4 to 22.9 mM . Digestion of total nonstructural carbohydrates was not altered (P > 0.05) by the treatments and averaged 86% . With the exception of increased (P < 0.05) concentration of propionate (from 42.0 to 51.5 mM) and decreased (P < 0.05) concentration of butyrate (from 25.9 to 16.3 mM), no effects (P > 0.05) were detected for monensin/tylosin . Ruminal N metabolism, including efficiency of bacterial protein synthesis (averaging 21.2 g N/kg OM truly digested), was not affected (P > 0.05) by the treatments . Results suggest positive effects of ethoxyquin on ruminal digestion of OM and unique changes in VFA production. J Anim Sci, 2002 Apr, 80(4), 1105 - 11 Utilization of distillers grains from the fermentation of sorghum or corn in diets for finishing beef and lactating dairy cattle; Al-Suwaiegh S et al.; Beef finishing and dairy lactation experiments were conducted to evaluate the nutritional value of distillers grains (DG) from sorghum or corn fermentation, in both wet (35.4% DM) and dry (92.2% DM) form (dairy trial only) . In the finishing experiment, 60 yearling steers were used in a completely randomized design with three diets that were fed for 127 d: 1) control diet with 86% (DM basis) dry-rolled corn and no DG; 2) 30% of ration DM as wet corn DG in place of dry-rolled corn; and 3) 30% of ration DM as wet sorghum DG in place of dry-rolled corn . All diets contained a minimum of 6.8% degradable intake protein and 13.0% CP . Steers fed DG had 10% greater ADG (< 0.01) and 8% greater efficiency of gain (P < 0.01) than steers fed the control diet . Wet corn and sorghum DG resulted in similar ADG and efficiency of gain . Hot carcass weights, fat thickness, and yield grades were greater for steers fed DG than for controls (P < 0.07) . Improvements in ADG and feed efficiency observed when DG replaced dry-rolled corn indicated that the NEg content of wet DG is approximately 29% greater than that of dry-rolled corn . In the dairy lactation experiment, 16 lactating Holstein cows (eight multiparous, including four fistulated) were used in a replicated 4 x 4 Latin square design with 4-wk periods . Corn and sorghum DG were fed at 15% of the ration DM in either wet or dry form . Diets were fed as total mixed rations that contained 50% of a 1:1 mixture of alfalfa and corn silages, 24.3% ground corn, and 9.1% soybean meal (DM basis) . There was no effect of source or form of DG on DMI, ruminal pH and VFA, or in situ digestion kinetics of NDF from DG . Efficiency of milk production was unaffected by diet . Corn and sorghum DG resulted in relatively similar performance when fed to beef or dairy cattle in this study. Plant J, 2002 May, 30(3), 329 - 36 The ethanolic fermentation pathway supports respiration and lipid biosynthesis in tobacco pollen; Mellema S et al.; Rapid pollen tube growth requires a high rate of sugar metabolism to meet energetic and biosynthetic demands . Previous work on pollen sugar metabolism showed that tobacco pollen carry out efficient ethanolic fermentation concomitantly with a high rate of respiration (Bucher et al., 1995) . Here we show that the products of fermentation, acetaldehyde and ethanol, are further metabolised in a pathway that bypasses mitochondrial PDH . The enzymes involved in this pathway are pyruvate decarboxylase, aldehyde dehydrogenase and acetyl-CoA synthetase . Radiolabelling experiments show that during tobacco pollen tube growth label of 14C-ethanol is incorporated into CO2 as well as into lipids and other higher molecular weight compounds . A role for the glyoxylate cycle appears unlikely since activity of malate synthase, a key enzyme of the glyoxylate cycle, could not be detected. Biosci Biotechnol Biochem, 2002 Feb, 66(2), 378 - 84 Transepithelial transport of the bioactive tripeptide, Val-Pro-Pro, in human intestinal Caco-2 cell monolayers; Satake M et al.; Some of the food-derived tripeptides with angiotensin converting enzyme (ACE)-inhibitory activity have been reported to be hypotensive after being orally administered . The mechanism for the intestinal transport of these tripeptides was studied by using monolayer-cultured human intestinal Caco-2 cells which express many enterocyte-like functions including the peptide transporter (PepT1)-mediated transport system . Val-Pro-Pro, an ACE-inhibitory peptide from fermented milk, was used as a model tripeptide . A significant amount of intact Val-Pro-Pro was transported across the Caco-2 cell monolayer . This transport was hardly inhibited by a competitive substrate for PepT1 . Since no intact Val-Pro-Pro was detected in the cells, Val-Pro-Pro apically taken by Caco-2 cells via PepT1 was likely to have been quickly hydrolyzed by intracellular peptidases, producing free Val and Pro . These findings suggest that PepT1-mediated transport was not involved in the transepithelial transport of intact Val-Pro-Pro . Paracellular diffusion is suggested to have been the main mechanism for the transport of intact Val-Pro-Pro across the Caco-2 cell monolayer. Biosci Biotechnol Biochem, 2002 Feb, 66(2), 307 - 18 L-erythrulose production by oxidative fermentation is catalyzed by PQQ-containing membrane-bound dehydrogenase; Moonmangmee D et al.; Thermotolerant Gluconobacter frateurii CHM 43 was selected for L-erythrulose production from mesoerythritol at higher temperatures . Growing cells and the membrane fraction of the strain rapidly oxidized mesoerythritol to L-erythrulose irreversibly with almost 100% of recovery at 37 degrees C . L-Erythrulose was also produced efficiently by the resting cells at 37 degrees C with 85% recovery . The enzyme responsible for mesoerythritol oxidation was found to be located in the cytoplasmic membrane of the organism . The EDTA-resolved enzyme required PQQ and Ca2+ for L-erythrulose formation, suggesting that the enzyme catalyzing meso-erythritol oxidation was a quinoprotein . Quinoprotein membrane-bound mesoerythritol dehydrogenase (QMEDH) was solubilized and purified to homogeneity . The purified enzyme showed a single band in SDS-PAGE of which the molecular mass corresponded to 80 kDa . The optimum pH of QMEDH was found at pH 5.0 . The Michaelis constant of the enzyme was found to be 25 mM for meso-erythritol as the substrate . QMEDH showed a broad substrate specificity toward C3-C6 sugar alcohols in which the erythro form of two hydroxy groups existed adjacent to a primary alcohol group . On the other hand, the cytosolic NAD-denpendent meso-erythritol dehydrogenase (CMEDH) of the same organism was purified to a crystalline state . CMEDH showed a molecular mass of 60 kDa composed of two identical subunits, and an apparent sedimentation constant was 3.6 s . CMEDH catalyzed oxidoreduction between mesoerythritol and L-erythrulose . The oxidation reaction was observed to be reversible in the presence of NAD at alkaline pHs such as 9.0-10.5 . L-Erythrulose reduction was found at pH 6.0 with NADH as coenzyme . Judging from the catalytic properties, the NAD-dependent enzyme in the cytosolic fraction was regarded as a typical pentitol dehydrogenase of NAD-dependent and the enzyme was independent of the oxidative fermentation of L-erythrulose production. Int J Food Microbiol, 2002 May 5, 75(1-2), 27 - 38 Protein expression during lag phase and growth initiation in Saccharomyces cerevisiae; Brejning J et al.; In order to obtain a better understanding of the biochemical events taking place in Saccharomyces cerevisiae during the lag phase, the proteins expressed during the first hours after inoculation were investigated by two-dimensional (2-D) gel electrophoresis and compared to those expressed in late respiratory growth phase . The studies were performed on a haploid strain (S288C) grown in defined minimal medium . Some of the abundant proteins, whose expression relative to total protein expression was induced during the lag phase, were identified by MALDI MS, and the expression of the corresponding genes was assessed by Northern blotting . The rate of protein synthesis was found to increase strongly during the lag phase and the number of spots detected on 2-D gels increased from 502 spots just after inoculation to 1533 spots at the end of the lag phase . During the first 20 min, the number of detectable spots was considerably reduced compared to the number of spots detected from the yeast in respiratory growth just prior to harvest and inoculation (747 spots), indicating an immediate pausing or shutdown in synthesis of many proteins just after inoculation . In this period, the cells got rid of most of their buds . The MALDI MS-identified, lag phase-induced proteins were adenosine kinase (Ado1p), whose cellular role is presently uncertain, cytosolic acetaldehyde dehydrogenase (Ald6p) and (DL)-glycerol-3-phosphatase 1, both involved in carbohydrate metabolism, a ribosomal protein (Asc1p), a fragment of the 70-kDa heat shock protein Ssb1, and translationally controlled tumour protein homologue (Yk1056cp), all involved in translation, and S-adenosylmethionine synthetase I involved in biosynthesis reactions . The level of mRNA of the corresponding genes was found to increase strongly after inoculation . By pattern matching using previously published 2-D maps of yeast proteins, several other lag phase-induced proteins were identified . These were also proteins involved in carbohydrate metabolism, translation, and biosynthesis reactions . The identified proteins together with other, yet unidentified, lag phase-induced proteins are expected to be important for yeast growth initiation and could be valuable biological markers for yeast performance . Such markers would be highly beneficial in the control and optimisation of industrial fermentations. Steroids, 2002 Jun, 67(7), 549 - 54 Two new C-nor/D-homo corticosteroids formed by dehydration rearrangement of a 12beta-hydroxy corticoid; Fu X et al.; Two new C-nor/D-homo corticosteroids were isolated from the filtrate of the triene carbonate intermediate during the production of betamethasone . Their structures were elucidated based on NMR spectroscopic studies and mass spectral analyses . The mechanism of formation of each of these two steroids was postulated as a Wagner-Meerwein rearrangement of the corresponding 12beta-hydroxy steroid . The new 12beta-hydroxy corticosteroid was also isolated from the fermentation process of betamethasone synthesis . Its structure was identified via NMR and mass spectroscopic studies . Treatment of the new 12beta-hydroxy corticoid with PCl(5) at low temperature provided two C-nor/D-homo compounds in a ratio of 1:1 . Conversion of 12beta-hydroxy corticoid into a corresponding 12beta-mesylate followed by heating in HOAc to 110 degrees C in the presence of NaOAc produced a mixture of the rearranged products in a 1:4 ratio. Appl Biochem Biotechnol, 2002 Feb, 97(2), 105 - 21 Low-temperature brewing by freeze-dried immobilized cells; Bekatorou A et al.; We propose a novel biocatalyst in brewing . A cryotolerant strain of Saccharomyces cerevisiae was immobilized on delignified cellulosic material followed by freeze-drying of the immobilized cells without the use of any cryoprotectant . The freeze-dried immobilized biocatalyst was used in repeated-batch fermentation of wort and showed reduced fermentation time and increased productivities as compared with free freeze-dried cells (FFDCs) . It also demonstrated suitability for low-temperature brewing (5 and 0 degrees C) . The fermentation time in repeated-batch fermentations at 15 degrees C was 1.5-2 d for a period of 13 mo, showing a high operational stability of the system . At 0 degrees C the freeze-dried immobilized biocatalyst showed a 2- to 3.5-fold decrease in fermentation time in comparison with FFDCs . Polyphenol contents, bitterness, and diacetyl concentration were lower in beers produced by freeze-dried immobilized cells as compared with FFDCs . At 0 degrees C polyphenols were 40% lower than at 15 degrees C . Higher alcohols were reduced and ethyl acetate increased in comparison with FFDCs . Amyl alcohols at 0 degrees C were lower than half of their content at 15 degrees C, while ethyl acetate was 31 mg/L at 0 degrees C and 18 mg/L at 15 degrees C . These data justify the improved aroma and taste of beers produced by freeze-dried immobilized biocatalyst mainly at low temperatures. Biotechnol Bioeng, 2002 Jun 20, 78(6), 658 - 69 An assessment of seed quality and its influence on productivity estimation in an industrial antibiotic fermentation; Cunha CC et al.; This study investigates the benefits of including seed quality information into data-based models for final productivity estimation in an industrial antibiotic fermentation process . Multiway principal component analysis is applied to assess the seed quality using routinely gathered plant data . Multiway partial least-squares regression is then used to estimate the final productivity using data from the main fermentation only . The issue of selecting appropriate process variables as inputs is investigated . Subsequently, seed characteristics are included into the estimation models to assess the benefits of including information from this stage for productivity estimation . It is shown that it is possible to extract seed fermentation features related to the final productivity both at pilot and production scales . It is postulated that significant influential variations are mirrored in monitored variables during the main fermentation, and therefore seed quality is implicitly accounted for . Int J Cancer, 2002 May 20, 99(3), 424 - 6 Novel epidemiologic evidence for the association between fermented fish sauce and esophageal cancer in South China; Ke L et al.; Previous studies have suggested that fermented fish sauce is related to an increased risk for nasopharyngeal, thyroid and gastric cancers and has suspicious carcinogenic and promoting effects in the laboratory, but these reports have not investigated the association between this agent and esophageal cancer in population . Therefore, we investigated the relationship between esophageal cancer and consumption of fermented fish sauce, alcohol and tobacco after adjusting other risk factors using data from a large hospital-based case-control study in Chaoshan area of China . The subjects for analysis included 1,248 cases (median age 58.5 {range 29-82} years, 936 males, 312 females, some 50% with the habit of fermented fish sauce eating) with squamous cell carcinoma of the esophagus and the same amount of controls matched by sex and age . A significant increase in risk (OR 3.21; 95% CI 2.45-4.19) for eating fermented fish sauce compared to not eating and a significant dose-response relationship was found with the consumption of fermented fish sauce (p for trend < 0.001) . In comparison based on the binary variables, the OR for the subjects with fermented fish sauce eating and current smoking was 15.5 with a 95% CI of 8.14-29.3, relative to those exposed to neither habit . The joint effect of fermented fish sauce (F) and smoking (S) was more than additive (F * S > F + S: 15.5 > 1 + (5.6 - 1) + (6.6 - 1)), but the effect for fermented fish sauce and alcohol was not found . It is concluded that risks of esophageal cancer in the population were substantially associated with fermented fish sauce . Further epidemiologic and experimental study are required to find a biologic causal relationship between them . Bioresour Technol, 2002 May, 82(3), 277 - 84 Oyster mushroom cultivation with rice and wheat straw; Zhang R et al.; Cultivation of the oyster mushroom, Pleurotus sajor-caju, on rice and wheat straw without nutrient supplementation was investigated . The effects of straw size reduction method and particle size, spawn inoculation level, and type of substrate (rice straw versus wheat straw) on mushroom yield, biological efficiency, bioconversion efficiency, and substrate degradation were determined . Two size reduction methods, grinding and chopping, were compared . The ground straw yielded higher mushroom growth rate and yield than the chopped straw . The growth cycles of mushrooms with the ground substrate were five days shorter than with the chopped straw for a similar particle size . However, it was found that when the straw was ground into particles that were too small, the mushroom yield decreased . With the three spawn levels tested (12%, 16% and 18%), the 12% level resulted in significantly lower mushroom yield than the other two levels . Comparing rice straw with wheat straw, rice straw yielded about 10% more mushrooms than wheat straw under the same cultivation conditions . The dry matter loss of the substrate after mushroom growth varied from 30.1% to 44.3% . The straw fiber remaining after fungal utilization was not as degradable as the original straw fiber, indicating that the fungal fermentation did not improve the feed value of the straw. Proteomics, 2001 Sep, 1(9), 1133 - 48 Similarity of the Escherichia coli proteome upon completion of different biopharmaceutical fermentation processes; Champion KM et al.; A comprehensive view of the physiological state of Escherichia coli cells at the completion of fermentation processes for biopharmaceutical production was attained via two-dimensional gel electrophoretic analysis of cellular proteins . For high cell density fermentations in which phosphate is depleted to induce recombinant protein expression from the alkaline phosphatase promoter, proteome analysis confirms that phosphate limitation occurs . Known phosphate starvation inducible proteins are observed at high levels; these include the periplasmic phosphate binding protein and the periplasmic phosphonate binding protein . The phn (EcoK) locus of these E . coli K-12 strains remains cryptic, as demonstrated by failure to grow with phosphonate as the sole phosphorus source . Proteome analysis also provided evidence that cells utilize alternative carbon and energy sources during these fermentation processes . To address regulatory issues in the biopharmaceutical industry, comparative electrophoretic analyses were conducted on a qualitative basis for four different fermentation processes . Using this approach, the protein profiles for these processes were found to be highly similar, with the vast majority (85-90%) of proteins detected in all profiles . The observed similarity in proteomes suggests that multiproduct host cell protein immunoassays are a feasible means of quantifying host-derived polypeptides from a variety of biopharmaceutical fermentation processes. Nat Prod Lett, 2002 Apr, 16(2), 87 - 93 3,4-Dihydroxy-7,8-dihydro-beta-ionone 3-O-beta-D-glucopyranoside and other glycosidic constituents from apple leaves; Stingl C et al.; 3,4-Dihydroxy-7,8-dihydro-beta-ionone 3-O-beta-D-glucopyranoside 1 has been isolated from a methanolic extract of apple (Malus domestica) leaves by XAD-2 adsorption chromatography and subsequent purification by high speed countercurrent chromatography (HSCCC) and HPLC . Under acidic conditions this glycoside gives rise to a number of volatile compounds including 1,1,6-trimethyl-1,2-dihydronaphthalene (TDN) 2, which is known as an off-flavor compound in wine . In the course of the study, six additional glycoconjugates were isolated from apple leaves, i.e . roseoside 3, 3-oxo-alpha-ionol beta-D-glucopyranoside 4, benzoic acid beta-D-glucose ester 5, kaempferol 3-O-rhamnoside 6, (+)-syringaresinol beta-D-glucopyranoside 7 and 4-hydroxy-5-(3''-methyl-2''-butenyl)-benzoic acid methylester 3-beta-D-glucopyranoside 8 . The latter compound has been isolated for the first time in nature . In order to avoid the 'kerosene-off-flavor' caused by TDN, the methanolic extract has been subjected to yeast fermentation . This treatment reduced the amount of TDN formed and resulted in an improved flavor impression of the methanolic extract. Microbiology, 2002 May, 148(Pt 5), 1397 - 406 Identification of novel sulfur-containing bacterial polyesters: biosynthesis of poly(3-hydroxy-S-propyl-omega-thioalkanoates) containing thioether linkages in the side chains; Ewering C et al.; This study describes the biosynthesis of novel sulfur-containing polyhydroxyalkanoates (PHAs), which consist exclusively of hydroxypropylthioalkanoic acid containing thioether groups in the side chains . In addition, the utilization of alkylthioalkanoic acids (=thia fatty acids) by various bacteria was investigated . Based on feedings with propylthiooctanoic acid (PTO) or propylthiohexanoic acid, the metabolically engineered PHA-negative mutant PHB(-)4 of Ralstonia eutropha, which harbours plasmid pBBR1::phaC1 expressing the PHA synthase of Pseudomonas mendocina, synthesized two novel poly(3-hydroxy-S-propyl-omega-thioalkanoic) acids {poly(3HPTA)s} . A terpolyester consisting of 3-hydroxypropylthiobutyric acid (3HPTB), 3-hydroxypropylthiohexanoic acid (3HPTHx) and 3-hydroxypropyl- thiooctanoic acid (3HPTO) was synthesized from PTO, whereas a co-polyester of 3HPTB and 3HPTHx was synthesized from propylthiohexanoic acid . Fed-batch fermentation of R . eutropha PHB(-)4(pBBR1::phaC1) on PTO was done on a 26-litre scale, providing a cell density of 7.3 g l(-1), from which 45 g of the novel poly(3HPTB-co-3HPTHx-co-3HPTO) were isolated . The chemical structures of the poly(3HPTA)s were identified by gas chromatography/mass spectrometry, elemental sulfur analysis, partial pyrolysis and detailed mass spectrometric analysis, exhibiting 3HPTB, 3HPTHx and 3HPTO as constituents . These novel, hitherto undescribed, constituents of PHAs were randomly distributed in the co-polyesters. Med Lav, 2002 Jan-Feb, 93(1), 26 - 33 {Acute poisoning with carbon dioxide: report of 2 fatal cases}; Romeo L et al.; BACKGROUND: Carbon dioxide (CO2), a very high density gas, tends to stratify at the lowest levels of the atmosphere . It can be produced by neutral geothermal emissions, fermentative processes or by human and industrial activity . When carbon dioxide concentrations rise to a very high level in a confined and poorly ventilated space, the anoxic hazard is a very important cause of severe accidents that can involve workers and rescuers . At CO2 levels higher than 20% there is a very high risk of a fatal accident, also considering the odourless feature of this gas . OBJECT: Two fatal accidents in workers are described which occurred during inspection of a concrete well, built as a part of sewerage network in a rural area . In the weeks after the accident, composition and concentration of gases inside the well were analysed . We also considered the influence of an organic fertilizer called "pollina" which was found on the ground around the concrete well, in order to ascertain whether fermentation could alter the gas composition inside the well . METHODS: Samples of air and water were collected in the well and samples of the organic fertilizer (pollina) on the ground surrounding the concrete well were also taken . Different quantities of organic fertilizer (pollina) with or without water were incubated in airtight glass bottles and placed in a dark room at 20 degrees C temperature; analysis of air inside the glass bottles was performed after 7 and 18 days of incubation . All the samples of air and water were analysed by gas-chromatographic-mass-spectrometry . RESULTS: Analysis of the air samples collected inside the well after 2, 16 and 18 weeks after the accident showed a low concentration of O2 (range 4.2-9%), a high concentration of CO2 (range 5.9-12.3%), a normal level of N2 (range 78-85%) and a concentration of N2O between 0.03 and 0.19% . In water collected 2 weeks after the accident at the bottom of the concrete well, CO2 and N2O concentrations of respectively 222 mg/L and 2 mg/L were measured . In the bottles with "pollina" we found, at different times of incubation, high concentrations of CO2 (highest value 25.2%), low levels of O2 (lowest value 0.5%) and negligible concentrations of N2O (< 0.015%) . CONCLUSIONS: All these findings suggest that the atmosphere inside the concrete well was altered by the fermentative processes of pollina . The death of the two workers, caused by a poorly oxygenated atmosphere with a high concentration of carbon dioxide, can be classified under the confined space hypoxic syndrome (CSHS). J Ind Microbiol Biotechnol, 2002 May, 28(5), 297 - 301 Enhanced production of heterologous macrolide aglycones by fed-batch cultivation of Streptomyces coelicolor; Desai RP et al.; A media development program for the enhanced production of macrolide aglycones by Streptomyces coelicolor is described . Shake flask studies utilizing a yeast extract and a bakers' yeast increased production by 200% and 80%, respectively . However, ammonia generation and high pH were identified as potential problems in these enriched media . Studies in pH-controlled fermentors revealed that production stage pH significantly affects macrolide titers, with low pH (5.5) being more productive than high pH (6.5) . Implementation of glucose feeding in shake flask cultures reduced ammonia generation and controlled production stage pH, resulting in significantly enhanced productivities . The combined effects of media supplementation and glucose feeding resulted in a three to five-fold overall improvement in total macrolide aglycone titers, and is the first reported high-level (>1 g/l) production of recombinant polyketides in a heterologous host. J Ind Microbiol Biotechnol, 2002 May, 28(5), 280 - 3 Production of testosterone from phytosterol using a single-step microbial transformation by a mutant of Mycobacterium sp; Lo CK et al.; A testosterone (TS)-producing mutant, ST2, was derived from a phytosterol-assimilating and androst-4-ene-3,17-dione (AD)-producing bacterium, Mycobacterium sp . B-3805S, using nitrosoguanidine (NTG) mutagenesis . Production of TS from phytosterol using a single-step microbial transformation process by ST2 was investigated in a 5-l surface-aeration microprocessor-controlled fermentor loaded with a synthetic medium supplemented with 0.1% phytosterol, 2% glucose and 1% peptone at 30 degrees C . An increase in dissolved oxygen at the initial stage of fermentation favored the side-chain degradation of phytosterol to AD . Later in the fermentation, a decrease in the dissolved oxygen to zero resulted in a decrease in pH to 6.0 as well as the reduction of AD to TS . Under optimal fermentation conditions, the maximum conversion ratio of phytosterol to TS was 31% after 120 h cultivation . It was concluded that the control of dissolved oxygen in the fermentation culture is the most important parameter for production of TS from phytosterol via AD . TS was isolated from the fermentation culture by addition of Amberlite XAD-7 resin and was further purified by flash chromatography on a silica gel column . After crystallization, TS was obtained as needle crystals with the correct melting point. Mol Microbiol, 2002 Jan, 43(2), 449 - 58 Differential roles of two SARP-encoding regulatory genes during tylosin biosynthesis; Bate N et al.; The tylosin biosynthetic gene cluster of Streptomyces fradiae is remarkable in harbouring at least five regulatory genes, two of which (tylS and tylT) encode proteins of the Streptomyces antibiotic regulatory protein (SARP) family . The aim of the present work was to assess the respective contributions of TylS and TylT to tylosin production . A combination of targeted gene disruption, fermentation studies and gene expression analysis via reverse transcriptase-polymerase chain reaction (RT-PCR) suggests that tylS is essential for tylosin production and controls the expression of tylR (previously shown to be a global activator of the biosynthetic pathway) plus at least one other gene involved in polyketide metabolism or regulation thereof . This is the first demonstration of a SARP acting to control another regulatory gene during antibiotic biosynthesis . In contrast, tylT is not essential for tylosin production. Eur J Biochem, 2002 Apr, 269(8), 2052 - 9 ORF6 from the clavulanic acid gene cluster of Streptomyces clavuligerus has ornithine acetyltransferase activity; Kershaw NJ et al.; The clinically used beta-lactamase inhibitor clavulanic acid is produced by fermentation of Streptomyces clavuligerus . The orf6 gene of the clavulanic acid biosynthetic gene cluster in S . clavuligerus encodes a protein that shows sequence homology to ornithine acetyltransferase (OAT), the fifth enzyme of the arginine biosynthetic pathway . Orf6 was overexpressed in Escherichia coli (at approximately 15% of total soluble protein by SDS/PAGE analysis) indicating it was not toxic to the host cells . The recombinant protein was purified (to > 95% purity) by a one-step technique . Like other OATs it was synthesized as a precursor protein which underwent autocatalytic internal cleavage in E . coli to generate alpha and beta subunits . Cleavage was shown to occur between the alanine and threonine residues in a KGXGMXXPX--(M/L)AT (M/L)L motif conserved within all identified OAT sequences . Gel filtration and native electrophoresis analyses implied that the ORF6 protein was an alpha2beta2 heterotetramer and direct evidence for this came from mass spectrometric analyses . Although anomalous migration of the beta subunit was observed by standard SDS/PAGE analysis, which indicated the presence of two bands (as previously observed for other OATs), mass spectrometric analyses did not reveal any evidence for post-translational modification of the beta subunit . Extended denaturation with SDS before PAGE resulted in observation of a single major beta subunit band . Purified ORF6 was able to catalyse the reversible transfer of an acetyl group from N-acetylornithine to glutamate, but not the formation of N-acetylglutamate from glutamate and acetyl-coenzyme A, nor (detectably) the hydrolysis of N-acetylornithine . Mass spectrometry also revealed the reaction proceeds via acetylation of the beta subunit. Microb Ecol, 2002 Jan, 43(1), 92 - 106 Epub 2001 Dec 07. Functional groups and activities of bacteria in a highly acidic volcanic mountain stream and lake in Patagonia, Argentina; Wendt-Potthoff K et al.; Acidic volcanic waters are naturally occurring extreme habitats that are subject of worldwide geochemical research but have been little investigated with respect to their biology . To fill this gap, the microbial ecology of a volcanic acidic river (pH approximately equal to 0-1.6), Rio Agrio, and the recipient lake Caviahue in Patagonia, Argentina, was studied . Water and sediment samples were investigated for Fe(II), Fe(III), methane, bacterial abundances, biomass, and activities (oxygen consumption, iron oxidation and reduction) . The extremely acidic river showed a strong gradient of microbial life with increasing values downstream and few signs of life near the source . Only sulfide-oxidizing and fermentative bacteria could be cultured from the upper part of Rio Agrio . However, in the lower part of the system, microbial biomass and oxygen penetration and consumption in the sediment were comparable to non-extreme aquatic habitats . To characterize similarities and differences of chemically similar natural and man-made acidic waters, our findings were compared to those from acidic mining lakes in Germany . In the lower part of the river and the lake, numbers of iron and sulfur bacteria and total biomass in sediments were comparable to those known from acidic mining lakes . Bacterial abundance in water samples was also very similar for both types of acidic water (around 10(5) mL(-1)) . In contrast, Fe(II) oxidation and Fe(III) reduction potentials appeared to be lower despite higher biogenic oxygen consumption and higher photosynthetic activity at the sediment-water interface . Surprisingly, methanogenesis was detected in the presence of high sulfate concentrations in the profundal sediment of Lake Caviahue . In addition to supplementing microbiological knowledge on acidic volcanic waters, our study provides a new view of these extreme sites in the general context of aquatic habitats. Eur J Gastroenterol Hepatol, 2002 May, 14(5), 535 - 42 Predominance of caecal injury in a new dextran sulphate sodium treatment in rats: histopathological and fermentative characteristics; Moreau NM et al.; OBJECTIVES : Cyclic administrations of dextran sulphate sodium (DSS) alternating with distilled water usually induce chronic colitis after a few weeks . In order to obtain stable chronic colitis (without recovery or relapse) in a few days, a new continuous DSS treatment was tested and characterized . Short-chain fatty acids (SCFAs), which remain poorly documented in experimental colitis, were also investigated . METHODS : Thirty-six Sprague-Dawley rats were treated with 5% DSS for 7 days (DI) followed by 3% DSS for 7 days (DM) or 14 days (DF) . Control rats received only water . Inflammatory injuries in the caecum and the colon were assessed by macroscopic (colon length, caecum weight, damages score) and histological parameters . SCFAs (acetate, propionate, butyrate) were quantified individually in caecal, proximal and distal contents . RESULTS : Macroscopic and histological observations revealed that this continuous DSS treatment induced acute inflammation (DI) followed rapidly by chronic active colitis . The latter was uncommonly predominant in the caecum and the distal colon, and was also associated with some fermentative disturbances . Caecal SCFA concentrations decreased with DSS at DI and DM . The molar ratio of caecal butyrate increased with DSS . Acetate decreased in the colon while propionate increased . CONCLUSION : This new DSS treatment is able to induce in a few days stable chronic inflammation with caecal and distal predominant injuries, and mild fermentative caeco-colonic alterations . This model could contribute to the study of potential anti-inflammatory effects of prebiotics. J Nutr, 2002 May, 132(5), 1012 - 7 The effects of short-chain fatty acids on human colon cancer cell phenotype are associated with histone hyperacetylation; Hinnebusch BF et al.; The short-chain fatty acid (SCFA) butyrate is produced via anaerobic bacterial fermentation within the colon and is thought to be protective in regard to colon carcinogenesis . Although butyrate (C4) is considered the most potent of the SCFA, a variety of other SCFA also exist in the colonic lumen . Butyrate is thought to exert its cellular effects through the induction of histone hyperacetylation . We sought to determine the effects of a variety of the SCFA on colon carcinoma cell growth, differentiation and apoptosis . HT-29 or HCT-116 (wild-type and p21-deleted) cells were treated with physiologically relevant concentrations of various SCFA, and histone acetylation state was assayed by acid-urea-triton-X gel electrophoresis and immunoblotting . Growth and apoptotic effects were studied by flow cytometry, and differentiation effects were assessed using transient transfec