ISSN:
1432-0614
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
Abstract When Bacteroides xylanolyticus X5-1 was grown on xylose in batch culture, acetate, ethanol, H2, CO2 and formate were the main fermentation products. CO inhibited H2 formation by B. xylanolyticus X5-1. As a result, the product formation shifted to more ethanol and formate and less acetate. Furthermore, less biomass was produced. H2 had almost no effect on the product formation from xylose. In batch cultures, dihydroxyacetone, acetone, acetoin and acetol could act as electron acceptors during xylose metabolism. The electron acceptors were reduced to their corresponding alcohols. The product formation from xylose by B. xylanolyticus X5-1 shifted to mainly acetate and CO2, and an increased biomass yield was obtained. H2, ethanol and formate were no longer produced. In continuous cultures not only 1,2-propanediol was formed from acetol, but also acetone. The NADP-dependent ethanol dehydrogenase that was present in xylose-grown continuous-culture cells, was repressed when the organism was grown in the presence of acetol. However, another alcohol dehydrogenase was induced for reduction of the external electron acceptor.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00902744
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