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Journal ArticleDOI

Effect of urea on the production of 2,3-butanediol by K. oxytoca

01 Jan 1995-Bioprocess Engineering (Springer-Verlag)-Vol. 13, Iss: 1, pp 49-50
TL;DR: The production of 2,3- butanediol by K. oxytoca in batch cultures was studied by replacing the ammonium salts in the medium with the corresponding nitrogen equivalent in the form of urea and the cultures were unable to grow when urea was used both as the carbon and nitrogen source.
Abstract: This paper deals with the production of 2,3- butanediol by K. oxytoca in batch cultures. The effect of urea on various kinetic parameters was studied by replacing the ammonium salts in the medium with the corresponding nitrogen equivalent in the form of urea. The specific growth rate and the product yield in an unacclimatised batch culture were found to be 0.29 h−1 and 0.26 g·g−1 respectively. The acclimatised batch cultures on the other hand behaved similar to that grown using the original medium with a specific growth rate of 0.66 h−1 and the product yield of 0.345 g·g−1. However the cultures were unable to grow when urea was used both as the carbon and nitrogen source.
Citations
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Journal ArticleDOI
TL;DR: Various strategies for efficient and economical microbial 2,3-butanediol production, including strain improvement, substrate alternation, and process development, are reviewed and compared with regard to their pros and cons.

592 citations


Cites background from "Effect of urea on the production of..."

  • ...Urea and ammonium sulfate were identified as potential candidates (Laube et al., 1984a; Sivakumar et al., 1995)....

    [...]

Journal ArticleDOI
TL;DR: In this article, a low cost and high efficiency process for 2,3 butanediol (2,3-BDO) production by using Klebsiella sp. Zmd30 isolated from a hydrogen-producing anaerobic sludge was examined.

33 citations

References
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Journal ArticleDOI
TL;DR: The bioconversion of sugars present in wood hemicellulose to 2,3-butanediol by Klebsiella pneumoniae grown on high initial concentrations of sugars was investigated and the concentration of end products normally found at the termination of fermentation was shown to be noninhibitory to growth and substrate utilization.
Abstract: The bioconversion of sugars present in wood hemicellulose to 2,3-butanediol (hereafter referred to as butanediol) by Klebsiella pneumoniae grown on high initial concentrations (up to 10%) of sugars was investigated. Initial fermentation studies with a chemically defined medium suggested that sugar levels in excess of 2% could not be utlized even when a higher inoculum size (5 to 10%) was used. The addition of nutrient supplements, viz., yeast extract, urea, ammonium sulfate, and trace elements resulted in a 10 to 50% increase in butanediol yields, although sugar utilization remained incomplete. The concentration of end products normally found at the termination of fermentation was shown to be noninhibitory to growth and substrate utilization. Acetic acid was inhibitory at concentrations above 1%, although growth and butanediol yield were stimulated in cultures supplemented with lower levels of acetic acid. The efficient utilization of 4% substrate concentrations of d-glucose and d-xylose was achieved, resulting in butanediol yields of 19.6 and 22.0 g/liter, respectively.

97 citations

Journal ArticleDOI
TL;DR: A quantitative study of the growth and carbohydrate metabolism of Aerobacter aerogenes in continuous culture with particular reference to 2:3-butanediol production is described, with no sign of loss of butanediol-producing ability by any of the cultures.
Abstract: SUMMARY: A quantitative study of the growth and carbohydrate metabolism of Aerobacter aerogenes in continuous culture with particular reference to 2:3-butanediol production is described. The effects of varying dilution rate, oxygen uptake rate, pH value, temperature and CO2 pressure were studied. The optimum pH value was 5·0°6·0. The optimum temperature was 35–37° with a dilution rate of 0·2 hr−1. The rate of sugar metabolism was decreased by raising the CO2 pressure. In continuous culture the maximum diol output rate/1. of working volume exceeded the greatest rate reported for batch culture by a factor of three. The maximum diol concentration and yield as a percentage of the theoretical maximum were lower in continuous culture than in batch culture. Reasons for this are given. Some variants of the parent organism were found in continuous cultures but they caused no change in the yield of butanediol. There was no sign of loss of butanediol-producing ability by any of the cultures, some of which were maintained for 2,000 hr. For the first few generations the rate of production of butanediol actually increased.

64 citations

Journal ArticleDOI
TL;DR: Butanediol production by Aerobacter aerogenes NRRL B199 grown on glucose requires an optimal rate of aeration for the obtention of butanediol 2, 3 and 4 and it has been observed that KLa increases during the fermentation cycle.
Abstract: Butanediol production by Aerobacter aerogenes NRRL B199 grown on glucose requires an optimal rate of aeration for the obtention of butanediol 2, 3. In the absence of air, Aerobacter aerogenes NRRL B199 growth and production are weak. Agitation-aeration is necessary for producing the biomass, but an excess of oxygen proves to be toxic with regard to metabolite production. Oxygen is a limiting substrate with regard to growth and an inhibitor with regard to the specific metabolite productivity. This observation is discussed from a kinetic stand point and in relation to the search for the optimum oxygen transfer coefficient (KLa), which is found to be in the range of 50–100h−1. It has also been observed that KLa increases during the fermentation cycle. The initial substrate concentration effects the yield production of biomass and butanediol production. Low yields of butanediol are obtained at low initial sugar concentrations, but good yields of butanediol are obtained (0.45 g/g) at high concentrations of glucose (195 g/L). Carbon substrates and butanediol are inhibitors of cell growth while butanediol is not quite an inhibitor of the specific rate of butanediol production for the range of butanediol of 0–100 g/L.

56 citations