Abstract: A bioconversion reactor for the anaerobic fermentation of organic material. The bioconversion reactor (10) comprises a shell (12) enclosing a predetermined volume, an inlet port (24) through which a liquid stream containing organic materials enters the shell, and an outlet port (26) through which the stream exits the shell. A series of vertical and spaced-­apart baffles (30, 32) are positioned within the shell to force the stream to flow under and over them as it passes from the inlet to the outlet port. The baffles present a barrier to the microorganisms within the shell causing them to rise and fall within the reactor but to move horizontally at a very slow rate. Treatment detention times of one day or less are possible.

Abstract: A non-mixed vertical tower anaerobic digester and anaerobic digestion process provides passive concentration of biodegradable feed solids and microorganisms in an upper portion of a continuous digester volume and effluent withdrawal from the middle to bottom portion of the digester, resulting in increased solids retention times, reduced hydraulic retention times, and enhanced bioconversion efficiency. In addition, due to passive concentration of solids, the non-mixed anaerobic digester accommodates high solids loadings and provides separation of microbial phases within the continuous digester volume to achieve substantially complete bioconversion of biodegradable feedstock components.

Abstract: The suitability of three ascomycetous fungi, Aspergillus niger, A. awamori and Trichoderma reesei, as well as two basidiomycetes, Pleurotus ostreatus and Phanerochaete chrysosporium, for bioconversion of apple distillery slop was compared. Trichoderma and Phanerochaete degraded raw fiberes by 20%, producing filter cakes with 17% to 22% raw protein contents. Aspergillus spp. were superior in filtration time and COD reduction and were of the same efficiency in protein synthesis as Trichoderma and Phanerochaete, but did not degrade fibres. Pleurotus ostreatus did not degrade lignin under fermentation conditions used and could not compete with other fungi due to its slower growth.

Abstract: Production of Microbial Proteins.- Single Cell Protein Production from Petroleum Derivatives and Its Utilization as Food and Feed.- Trends on Optimization of Biomass Production Application to SCP Production.- The Economical Aspects of Single Cell Protein Production from Petroleum Derivatives.- Production of Single Cell Protein from Thermotolerant Methanol - Utilizing Cultures for Animal Feed.- Process for SCP Production Combining the Specific Advantages of Yeast and Bacteria Fermentation.- The Efficient Use of Water in Single Cell Protein Production.- Utilization of Microorganisms for the Production of Chemicals.- Isocitrate and Citrate Production by Saccharomycopsis lipolytica. Microbial as well as Engineering Approach.- Synthesis of Optically Active Amino Acids with Microbial Enzymes.- Concepts of Industrial Antibiotic Production.- Optimization of a Growth Medium for Antibiotic Production by Streptomyces anandii var. Taifiensis.- Microbial Treatment and Utilization of Waste.- Microbial Treatment and Utilization of Waste.- Biodegradation of Non-Cellulosic Waste for Environmental Conservation and Fuel Production.- Bioconversion of Cellulosic Waste into Protein and Fuel Products: A Case Study of the Technoeconomic Potentials.- Conversion of Cellulosics. Part 1. Structures of Cellulosic Materials and their Hydrolysis by Enzymes.- Conversion of Cellulosics. Part 2. Acid Hydrolysis and Chemicals from Cellulosics.- Bioconversion of Cellulosic Wastes.- Biological Removal of Nitrogen from Kuwait's Refinery Wastewater.- Reduction of Bacterial Contamination in Sewage Effluents and Soils of Saudi Arabia: Impact of Sewage Treatment Technology and Natural Self-Purification.- Biogas Production from Water Hyacinth Eichhornia crassipes (Mart.) Solms.- Catalytic Activity of Alkali Metals on the Thermochemical Conversion of Biomass Materials.- Continuous Culture.- Continuous Culture: A Tool for Research, Development and Production.- Membrane Bioreactors: A New Approach to Fermentation of Agricultural and Food Processing Wastes.- Application of Biotechnology in Plant Science.- Biotechnological Applications of Plant Tissue Cultures.- The Structure of Plant Genes as Exemplified by Pea Seed Storage Protein Genes and their Expression in Microorganisms.- Applied Microbiology and Environment.- The Microbial Spoilage of Foods.- Selenium Sorption by Some Selenotolerant Fungi.- Applied Microbiology and Biotechnology: International Cooperation Between Developed and Developing Countries.- Applied Microbiology and Biotechnology: International Cooperation between Developed and Developing Countries.- The Potential of Biotechnology for the Gulf Region and the Role of the International Centre for Genetic Engineering and Biotechnology (ICGEB).- Author Index.

Abstract: Coimmobilization of biocatalyst and substrate was studied as a method to increase the conversion rate in systems with substrates of extremely low solubility in water. The system studied was the conversion of hydrocortisone to prednisolone by Arthrobacter simplex. As a matrix for coimmobilization, alginate turned out to be superior to agar and agarose. After the reaction was complete, the beads were solubilized, andthe cells recovered for reuse, by centrifugation, whereas the prednisolone was extracted from the supernatant.

Abstract: Ethyl acetate produced via bioconversion processing has potential use as a 'natural' flavor and fragrance compound; for this reason the physiological manipulation of the yeast C. utilis to produce significant yields of this ester from glucose or ethanol has been studied. Production of the ester was dependent on the stage of growth. By use of iron-limited conditions, under adequate aeration, ethyl acetate accumulated from ethanol. Studies using specific metabolic inhibitors implicated acetyl-CoA as a key intermediate in formation of the ester. Chelators could be used to increase yield and specific production of ethyl acetate from glucose and ethanol. EDTA appeared to function at the level of cell permeability whereas EGTA or NTA may have encouraged larger acetyl-CoA pools to accumulate.

Abstract: Anaerobic digestion is an extensively used bioconversion process to produce gaseous fuel from native lignocellulosic materials. It consists essentially of two steps; acidogenesis and methanogenesis. Most conventional anaerobic digesters are single-stage systems. Animal waste, agricultural residues, sewage sludge and industrial effluents are suitable as feedstock. Biogas productivity in single stage digestion ranges from 0.5–1.5 m3/m3/day at mesophilic (20–40°C) and 1.0–2.5 m3/m3/day at thermophilic (40–60°C) temperatures, and about 30–50% of the volatile solids are converted to biogas. In two-stage systems, acidogenesis is separated from methanogenesis, which improves cellulose hydrolysis and process efficiency. Recent advances in digester design include the introduction of the upflow anaerobic sludge blanket, and fluidized-bed and fixed-film bioreactors, which are operated at much higher loading. Process efficiency can be as high as 97%. An overview of these technologies is presented.

Abstract: The bioconversion of 17α-ethynyl steroids was effected with 11α-hydroxylase ofRhizopus nigricans. 7β-Hydroxyethisterone was found after the bioconversion of ethisterone, and 10β- and 6β-hydroxy derivatives after the bioconversion of norethisterone. It seems that the ethynyl group prevents steroid-enzyme binding in the normal mode and thus inhibits the formation of an 11α-hydroxylated product.

Abstract: This invention provides a bioconversion process for producing stable isotope labelled biochemicals. In one embodiment, Methylophilus viscogenes strain ATCC 39893 is cultivated with 13 C-methanol as the sole growth carbon source to produce an accumulated quantity of extracellular uniformly labelled 13 C-heteropolysaccharide Poly 54.

Abstract: The structures of two bioconversion products of a carboxylic ionophorous antibiotic, grisorixin, have been determined by means of two-dimensional n.m.r. The potassium salt conformations of grisorixin and its bioconversion products are very similar. Grisorixin metabolites still complex the cations, but no longer transport them, and have no antibiotic activity.

Abstract: Pseudomonas AM1 utilizes glycine and methanol to producel-serine aerobically(1). The consumption of methanol in this bioconversion is stoichiometrically in excess of L-serine production(2). Consequently, the oxygen requirement associated with L-serine production is higher than expected for the conversion from glycine.

Abstract: The full report describes a 5-year investigation on the conversion of cellulosic materials and wastes to glucose, potentially an enormous source of ethanol and a wide range of petrochemicals. Employing a co-rotating twinscrew extruder as reaction vessel, the process achieves a fully continuous dilute-acid hydrolysis at temperatures around 240°C and residence times of 5 to 10 seconds. It handles feedstocks ranging from waste paper pulp at 10% solids to corn bran to dry hardwood sawdust at 95% solids without pretreatment and gives good conversion yields, around 60% of the available cellulose, with low energy consumption. Using- a feasibility study based on accurately measured material and energy balances, economically attractive projections are given for scale-up from the 2 ton per day pilot plant, which has operated for three years, to a full-scale commercial plant producing 25 million gallons of ethanol per year. Also given is a description of work on separation of the product, analytical techniques, studies on fermentation and bioconversion to methane and utilization of the hemicellulose and lignin fractions of the plant material. Environmental considerationsare discussed, as well as a proposal for a mobile version.

Abstract: Various processes have been developed or proposed for converting cellulosic residues from forestry and agricultural operations into products which can be used for fuel or food. Among the promising practical possibilities are processes for ethanol, methane and microbial protein production by fermentation technology. The results of technoeconomic sensitivity analyses of these three process options indicate that microbial protein production for animal food applications is the most attractive followed by methane then ethanol, the last being quite uneconomical at present for North America. Ironically, research emphasis seems to be placed in the reverse order. It is evident that the relevant costs of upstream and downstream processing in the various process proposals have not been adequately addressed. A case study of the potential utilization of paper pulpmill sludge utilization illustrates the general and specific concerns of the various strategies.

Abstract: The bioconversion of benzimidazole to 5-hydroxybenzimidazole was investigated as a function of the physiological state of the fungus and culture conditions. Using an inoculum composed only of spores, the addition of benzimidazole at different times of development led to a better definition of optimal physiological conditions for obtaining a good hydroxylation yield. The relationship between the degree of hydroxylation and that of culture medium aeration, was shown by the use of four different conditions: flowing medium on an inert support, in static, agitated or highly aerated medium.

Abstract: Fungi may be useful for low-cost, low-energy-requiring processing of fossil fuels. We investigated the suitability of peat hydrolysate as a growth medium for a fungus that may be able to produce chemicals from fossil fuels, either as secondary metabolities or lignin-degradation products. The biomass yield was greater in phosphate-amended cultures than yields reported for other species grown on peat hydrolysate. Supplemental carbohydrate with phosphate increased the biomass but reduced the efficiency of carbohydrate utilization. There was no evidence of growth inhibitors in the hydrolysate, and a reduction in fulvic acid concentration did not enhance growth. It was postulated that based on this and studies in the literature, the suitability of peat hydrolysate as a growth substrate may be dependent on the source of peat and method of hydrolysis, as well as the organism.

Abstract: L-Phenylalanine is produced continuously in bioreactors utilising whole microbiol cells containing a specific phenylalanine dehydrogenase The reaction requires reducing equivalents (NADH) to aminate the phenylpyruvic acid precursor and these are supplied continuously by in vivo generation using a suitable oxidisable substrate (eg formate, lactate or pyruvate) and the respective dehydrogenase reaction By direct coupling, an in vivo phenylalanine and formate (or lactate or pyruvate) dehydrogenase system enables cells to be used in a bioconversion medium devoid of all the growth-promoting components Cells can be immobilised by entrapment and manipulated for prolonged periods of time to produce phenylalanine in high yields by continuously regenerating reducing equivalents via directly-coupled oxidisable substrates The latter facilitates simple and rapid recovery of the phenylalanine product