Abstract: EightLactobacillus species were screened for production of lactic acid from acid-hydrolyzed municipal solid waste (AHMSW). Screening criteria included carbohydrate utilization, lactic acid production, and the yield of lactic acid produced in modified Elliker broth and in MSW hydrolyzate.Lactobacillus pentosus B-227 metabolized the most carbohydrate (62%) and produced the highest concentration of lactic acid in AHMSW (21.2 mg/mL) containing 41.3 mg/mL carbohydrate. Fermentation parameters for the bioconversion of carbohydrates in MSW to lactic acid also were evaluated. Under optimum conditions, consisting of an initial pH of 7.6, 32‡C, static fermentation, 1% v/v inoculum, and 5% calcium carbonate buffer, L.pentosus B-227 produced 65 mg/mL lactic acid from 100.6 mg/mL of carbohydrates in MSW hydrolyzate, an 87% yield based on carbohydrate utilization.

Abstract: The bioconversion of xylose into xylitol in fed-batch fermentation with a recombinantSaccharomyces cerevisiae strain, transformed with the xylose-reductase gene ofPichia stipitis, was studied. When only xylose was fed into the fermentor, the production of xylitol continued until the ethanol that had been produced during an initial growth phase on glucose, was depleted. It was concluded that ethanol acted as a redox-balance-retaining co-substrate. The conversion of high amounts of xylose into xylitol required the addition of ethanol to the feed solution. Under O2-limited conditions, acetic acid accumulated in the fermentation broth, causing poisoning of the yeast at low extracellular pH. Acetic acid toxicity could be avoided by either increasing the pH from 4.5 to 6.5 or by more effective aeration, leading to the further metabolism of acetic acid into cell mass. The best xylitol/ethanol yield, 2.4 gg−1 was achieved under O2-limited conditions. Under anaerobic conditions ethanol could not be used as a co-substrate, because the cell cannot produce ATP for maintenance requirements from ethanol anaerobically. The specific rate of xylitol production decreased with increasing aeration. The initial volumetric productivity increased when xylose was added in portions rather than by continuous feeding, due to a more complete saturation of the transport system and the xylose reductase enzyme.

Abstract: An engineering study was conducted to evaluate the engineering economics of producing calcium magnesium acetate (CMA), using different kinds of residue biomass as feedstock (sewage sludge, biomass, municipal solid wastes, industrial wastes etc.). This study focused on bioconversion of cellulose (as a model organic) to CMA based on ‘suppressed methane’ fermentation of the organic residue to produce acetic acid, followed by liquid ion exchange to recover the acetic acid from the fermenter broth, with subsequent reaction with dolime to form CMA, which is dried to a white crystalline salt. Preliminary economic analysis revealed that the base line production cost for CMA was $358 (metric) tonne ($325 per US ton). However, with the assumption of a ‘credit’ for the disposal of the residue biomass, CMA can be more competitive. For example, it was found with a credit of $1210 per t ($1100 per US ton) for disposal of sewage sludge, the costs result in a plus $825 per t ($750 per US ton) CMA produced.

Abstract: Bioconversion of alkali-soluble coal, sulfonated lignin, and dimethoxybenzyl alcohol (DMBA) byPenicillium citrinum was investigated with respect to the effects of (1) these compounds on growth and metabolism, and (2) the organism on the chemical nature of coal and DMBA. Alkali-soluble coal caused a slight enhancement of grwoth and metabolism; DMBA and lignin partially inhibited growth and metabolism. Both whole cells and cell-free extracts were capable of oxidation of DMBA to dimethoxybenzaldehyde. Whole cells demonstrated the capability of modifying alkali-soluble Beulah Zap and Ugljevik lignite coals by producing compounds that were of lower and higher molecular weight than the original coal. In vivo conversion of alkali-soluble Ugljevik coal resulted in a substantial decrease in the sulfur content of the coal (52% decrease). Cell-free extracts were able to degrade alkali-soluble Ugljevik lignite coal. The results suggest a potential usefulness of this microorganism for coal bioprocessing.

Abstract: The Pseudomonas fluorescens N3 was isolated from soil for its ability to utilize naphthalene as a carbon source. The strain transforms 2,3-dimethyl-, 2-methoxy-, 1- and 2-ethylnaphthalenes to the corresponding salicylic acids competitively with chemical synthesis. The identification of 2-hydroxy-2-carboxy-7-ethylchromane by biotransformation of 2-ethylnaphthalene, contributes to elucidating the steps involved in the catabolic pathways of naphthalenes to salicylaldehydes.

Abstract: The bioconversion of octanoic acid into 2-heptanone by spores of Penicillium roquefortii is performed using a fed-batch technique with pH control by addition of the liquid substrate itself. The early stage of this process takes place with a high bioconversion rate and high yield. These values then decrease as a result of germination and growth the biocatalyst. An optimization strategy for the process would thus be to improve the characteristics of this first period, i.e., increase its duration and the reaction rate. An increase in duration is evidenced in two cases: (I) under oxygen limitation: and (ii) when the spore content in the medium is less than 10(7) spores/mL. These conditions give insufficient overall bioconversion rates: better optimization should be achieved without oxygen limitation and with high spore content. Characterization of the first period by material and bioenergetic balances suggests that an increase in the ethanol content of the medium, which acts as an energy source and a permeabilizer, and the use of specific inhibitor of the Krebs cycle, may be a way to further improve the biocatalyst performance and stability.

Abstract: The xylose conversion into xylitol by Candida guilliermondii was evaluated in semi-synthetic media supplemented with different nitrogen sources in a ratio C/N equal 25.6. It was noticed that the xylitol yield was around 80% and also that the type of nitrogen source did not influence this bioconversion.

Abstract: Pseudomonas fluorescens strain BTP9 is used as biocatalyst to produce vanillic acid from vanillin. Several two-phase reactors were investigated and compared to the corresponding one-phase systems in order to optimize this bioconversion.

Abstract: There is disclosed a novel microbial bioconversion process for the synthesis of a trans-hydroxy sulfone intermediate, which is the precursor to topical carbonic anhydrase inhibitors (TCAI's). TCAI's are effective in the treatment of glaucoma and ocular hypertension. The bioconversion process is carried out in the presence of the microorganism Rhodotorula rubra, or Rhodotorula piliminae and results in a trans-hydroxy sulfone which exhibits a diastereomeric excess of greater than 95%.

Abstract: The fungus Pleurotus ostreatus NRRL-2366 degraded 56.7% and 45.9% of untreated and chemically pretreated (delignified) sugarcane bagasse, respectively, during 14-day incubation in a submerged fermentation process. The biodegradation percentages of cellulose, hemicellulose and lignin were 33.0%, 72.5% and 14.5%, respectively. An increment of 22.6% of crude protein content in the residual fermented material was observed. Chemical composition of the end-product and its amino acids profile were reported.

Abstract: Various physico-chemical parameters like medium composition, nature and the amount of carrier solvent, pH, substrate concentration and age of culture have been shown to considerably affect the bioconversion of cholesterol to 17-ketosteroids by MF NRRL B-8153. The optimum bioconversion yield was observed in peptone medium at 0.5 mg/ml cholesterol concentration using 3% acetone as a carrier solvent with 72 h old culture. Addition of surfactants in the bioconversion medium has proved deliterious to the process. The leaky natre of the microorganism used was overcome by the use of metabolic inhibitors

Abstract: Enantioselective bioconversion of organosilicon compounds was successfully carried out with hydrolases and a dehydrogenase. Substituents on silicon atom were found to affect the efficiency of the reactions. In many cases, the characteristics of silicon atom reflected the reactivity.

Abstract: The overall objective of the project is to develop an integrated two-stage fermentation process for conversion of coal-derived synthesis gas to a mixture of alcohols. This is achieved in two steps. In the first step, Butyribacterium methylotrophicum converts carbon monoxide (CO) to butyric and acetic acids. Subsequent fermentation of the acids by Clostridium acetobutylicum leads to the production of butanol and ethanol. The tasks for this quarter were: development/isolation of superior strains for fermentation of syngas; evaluation of bioreactor configuration for improved mass transfer of syngas; recovery of carbon and electrons from H{sub 2}-CO{sub 2}; initiation of pervaporation for recovery of solvents; and selection of solid support material for trickle-bed fermentation. Technical progress included the following. Butyrate production was enhanced during H{sub 2}/CO{sub 2} (50/50) batch fermentation. Isolation of CO-utilizing anaerobic strains is in progress. Pressure (15 psig) fermentation was evaluated as a means of increasing CO availability. Polyurethane foam packing material was selected for trickle bed solid support. Cell recycle fermentation on syngas operated for 3 months. Acetate was the primary product at pH 6.8. Trickle bed and gas lift fermentor designs were modified after initial water testing. Pervaporation system was constructed. No alcohol selectivity was shown with themore » existing membranes during initial start-up.« less

Abstract: . Inoculation of different plant wastes with microorganisms resulted in a release of maximum reducing sugars (33 %) from sugar-cane leaves when subjected to Penicillium oxalicun,. Maximum protein was formed from sugar-cane bagasse inoculated with Aspergillus fumigatus. Association of sugar-cane leaves with P. oxalicurn showed the highest digestibility. The use of such microorganisms may help to provide additional and valuable proteins ultimately for human use. Plant wastes have long been a subject of interest (due to their abundance, low cost, availability and regenerative capacity) for bioconversion to sugars and single-cell protein (Iyo and Antai 1988; Nojoku and Antai 1987; Chahal et al. 1979; Abd-Alla et al. 1992). The ability of the microorganism to utilize plant wastes depends on its enzymic activity (Stewart and Walsh 1972; EI-Nawawy et al. 1984) and this ability is usually limited by the low nitrogen content of these products (Rice 1979). A great number of microorganisms, mostly fungi and a few bacteria and actinomycetes, are able to degrade native cellulosic materials to soluble sugars (Bisaria and Ghose 1981; Coughlan 1985). In this investigation it was intended to study the capability of different microorganisms to degrade plant wastes to sugars and protein for some economic purposes, such as feedstuff manufac- ture. MATERIALS AND METHODS

Abstract: Bioconversion for Production of Renewable Transportation Fuels in the United States: A Strategic Perspective Cellulase and Xylanase Systems of Thermotoga neapolitana Structure-Function Studies of Endo-1,4-*b-D-glucanase E2 from Thermomonospora fusca Role of Cellulose-Binding Domain of Cellobiohydrolase I in Cellulose Hydrolysis CelS: A Major Exoglucanese Component of Clostridium thermocellum Cellulosome Plant Endo-1,4-*b-D-glucanases: Structure, Properties, and Physiological Function Approaches to Cellulase Purification Cellobiose Dehydrogenase: A Hemoflavoenzyme from Phanerochaete chrysoporium Cellulase Production Technology: Evaluation of Current Status Cellulase Assays: Methods from Empirical Mathematical Models Components of Trichoderma reesei Cellulase Complex on Crystalline Cellulose: Three-Dimensional Visualization with Colloidal Gold Deposition of Metallic Platinum in Blue-Green Algae Cells Genetic Engineering Approaches for Enhanced Production of Biodiesel Fuel from Microalgae Microbial and Enzymatic Biofuel Cells Pretreatment of Lignocellulosic Biomass Bioconversion of Wood Residues: Mechanisms Involved in Pretreating and Hydrolyzing Lignocellulosic Materials Development of Genetically Engineered Microorganisms for Ethanol Production Kinetic Consequences of High Ratios of Substrate to Enzyme Saccharification Systems Based on Trichoderma Cellulase Pectin-Rich Residues Generated by Processing of Citrus Fruits, Apples, and Sugar Beets: Enzymatic Hydrolysis and Biological Conversion to Value-Added Products Silage Processing of Forage Biomass to Alcohol Fuel Conversion of Hemicellulose Hydrolyzates to Ethanol Anaerobic Digestion of Municipal Solid Waste: Enhanced Cellulolytic Capacity Through High-Solids Operation Compared to Conventional Low-Solids Systems Role of Acetyl Esterase in Biomass Conversion Metabolism of Xylose and Xylitol by Pachysolen tannophilus

Abstract: 9(Z)-Octadecenamide, hexadecenamide, tetradecenamide and tetradecanamide were produced by a novel bioconversion of oleic acid withBacillus megaterium NRRL B-3437. Although chemical synthesis is more practical, the bioconversion to fatty amides (5–7% of total recovered lipids) was unique for its requirement of both enzymatic catalysis and equimolar oleic acid/ammonium salt substrates. Purified octadecenamide was obtained by silica gel and high-pressure liquid chromatographic procedures and was characterized by gas chromatography, mass spectrometry, infrared and nuclear magnetic resonance.