Showing papers on "2,3-Butanediol published in 1984"

Fermentation of 2,3-butanediol by Pelobacter carbinolicus sp. nov. and Pelobacter propionicus sp. nov., and evidence for propionate formation from C2 compounds

Abstract: From anaerobic enrichments with 2,3-butanediol as sole substrate pure cultures of new Gram-negative, strictly anaerobic, non-sporeforming bacteria were isolated. Similar isolates were obtained with acetoin as substrate. From marine muds in saltwater medium a short rod (strain Gra Bd 1) was isolated which fermented butanediol, acetoin and ethylene glycol to acetate and ethanol. The DNA base ratio of this strain was 52.3 mol% guanine plus cytosine.

Production of 2,3-butanediol from D-xylose by Klebsiella oxytoca ATCC 8724.

Abstract: It is known that 2,3-butanediol is a potentially valuable chemical feedstock that can be produced from the sugars present in hemicellulose and celluose hydrolysates. Klebsiella oxytoca is able to ferment most pentoses, hexoses, and disaccharides. Butanediol appears to be a primary metabolite, excreted as a product of energy methabolism. The theoretical maximum yield of butanediol from monosaccharides is 0.50 g/g. This article describes the effects of pH, xylose concentration, and the oxygen transfer rate on the bioconversion of D-xylose to 2,3-butanediol. Product inhibition by butanediol is also examined. The most important variable affecting the kinetics of this system appears to be the oxygen transfer rate. A higher oxygen supply favors the formation of cell mass at the expense of butanediol. Decreasing the oxygen supply rate increases the butanediol yield, but decreases the overall conversion rate due to a lower cell concentration.

Microbial production of 2,3-butanediol from whey permeate

Abstract: Of four organisms tested in semi-synthetic medium for the production of 2,3-butanediol from lactose, Klebsiella pneumoniae N.C.I.B. 8017 proved to be the most promising. When tested using rennet whey permeate as substrate, a butanediol concentration of 7.5 g/l, representing a yield of 0.46 g/g lactose utilized, was observed after 96 h incubation. In whey permeate where the lactose had been hydrolysed enzymatically prior to the fermentation, a butanediol concentration of 13.7 g/l, representing a yield of 0.39 g/g sugar utilized was obtained. These results indicate that lactose utilization may be a limiting step in the fermentation process.

The effect of yeast extract on the fermentation of glucose to 2,3-butanediol by Bacillus polymyxa

Abstract: The fermentation of glucose to 2,3-butanediol by Bacillus polymyxa was improved by increasing the amount of yeast extract in the culture medium. A level of 1.5% (w/v) resulted in optimal 2,3-butanediol production. A comparable fermentation could be achieved with 0.5% yeast extract if the phosphate level of the medium was increased from 0.0026 to 0.078 M and the medium was supplemented with 40 μM iron and 1.7 μM manganese.

The combined enzymatic hydrolysis and fermentation of hemicellulose to 2,3-butanediol

Abstract: Hemicellulose-rich fractions from several agricultural residues were converted to 2,3-butanediol by a combined enzymatic hydrolysis and fermentation process Culture filtrates from Trichoderma harzianum E58 were used to hydrolyze the substrates while Klebsiella pneumoniae fermented the liberated sugars to 2,3-butanediol Approximately 50–60% of a 5% (w/v) xylan preparation could be hydrolyzed and quantitatively converted to 2,3-butanediol using this procedure Although enzymatic hydrolysis was optimal at pH 50 and 50° C, the combined hydrolysis and fermentation was most efficient at pH 65 and 30° C Combined hydrolysis and fermentation resulted in butanediol levels that were 20–40% higher than could be obtained with a separate hydrolysis and fermentation process The hemicellulose-rich water-soluble fractions obtained from a variety of steam-exploded agricultural residues could be readily used by the combined hydrolysis and fermentation approach resulting in butanediol yields of 04–05 g/g of reducing sugar utilized

Application of bioenergetics to modelling the microbial conversion of D-xylose to 2,3-butanediol.

Abstract: During the oxygen limiting growth of Klebsiella oxytoca, the xylose metabolism may be considered as consisting of three components: conversion to 2,3-butanediol by "fermentation," oxidation to carbon dioxide by respiration, and assimilation to cell mass. The amount of energy required for the assimilation of cell mass is assumed to determine the extent to which the two energy producing reactions occur. The activity of each energy producing pathway is also determined by the availability of oxygen and by the energy yield of each pathway. These relationships can be quantified by equating the ATP required for growth and maintenance to the ATP produced by the energy producing reactions. The resulting equation for butanediol production appears similar to the Luedeking and Piret model where the parameters alpha and beta are related to the maximum cell yield from ATP and the maintenance energy requirement. These parameters were estimated from 14 batch fermentations, and the resulting simulation was used to describe the effects of the oxygen transfer rate and the initial xylose concentration on the yields and rates of the 2,3-butanediol fermentation.

Separation and Quantitation of 2,3-Butanediol Isomers ((−), (+), and meso) by a Combined Use of Enzyme and Gas Chromatography

Abstract: (1984). Separation and Quantitation of 2,3-Butanediol Isomers ((−), (+), and meso) by a Combined Use of Enzyme and Gas Chromatography. Agricultural and Biological Chemistry: Vol. 48, No. 11, pp. 2837-2838.

2,3‐Butanediol Production by Immobilized Cells of Enterobacter sp.a

Abstract: After the Second World War, there was little interest in production of 2,3-butanediol by fermentation until the late 1970s. 2,3-Butanediol may be used for the production of 1,3-butadiene, which can be used for making polybutadiene and styrene-butadiene gums. Butadiene can be produced from ethanol,’ but its production directly from 2,3-butanediol is cheaper.’ It can also be used as liquid fuel because of its great fuel value (27.2 MJ/kg). 2,3-Butanediol can be produced by many different microorganisms, but only a few species are suitable for industrial production. Typical 2,3-butanediol producers are Enterobacter, Klebsiella. Serratia. Aeromonas and some Bacillus spp. The formation of 2.3-butanediol is connected to the production of acetoin, ethanol, acetic acid, lactic acid, formic acid and succinic acid.’ The above-mentioned organisms are able to use pentoses and pentitols as their only carbohydrate source. Enterobacter aerogenes resembles Klebsiella pneumoniae, and they were earlier regarded as the same strain. Chua et a/.4 produced 2,3-butanediol using K-carrageenan bead-entrapped cells with glucose as substrate. The cells were not as sensitive to pH, temperature, and dissolved oxygen as the native cells. Furthermore, the formation of acetoin was significantly lower with immobilized cells. The production rate in a shake flask fermentation was 0.5 g/dm’/h and the yield was 60% of the theoretical value. In the continuous fermentation, the yield was 50% of the theoretical value, and 3 g/dm’ could be produced at least for 10 days. Chambers et aLs used, for 2,3-butanediol production, a bacterium isolated from decaying wood. Immobilizing cells on 12-mm Rasching rings, they were able to convert a 100 g/dm’ xylose solution at a rate three times as great as that for their conventional batch reactor. We have studied 2.3-butanediol production with immobilized cells. The organism, isolated from paper mill process waters, was identified as Enterobacter sp., and was shown to be the best 2,3-butanediol producer together with Klebsiella pneumoniae. Nutrients were supplied by Difco Labs. (USA), sodium alginate by BDH Chemicals (England), gelatin by Riedel de Haen AG (FRG), cellulose diacetate by Eastman Kodak Co. (USA), nylon net by 3M Co. (USA). Xylose was obtained from China. Enterobacter sp. free cells were cultivated by batch fermentation (unless otherwise mentioned) in a medium containing (weight/volume) 0.2% peptone, 0.3% yeast extract, 0.25% ammonium chloride, 0.02% magnesium chloride, 0.5% dipotassium hydrogen phosphate, and 5% xylose. The pH was 5.75. The cultivation was carried out for 22 h at 32 “C. After centrifugation (5900 g) the dry weight of the cells was 23%. Repeated batch fermentations were carried out in 250-cm’ Erlenmeyer flasks