Increased ethanol production and tolerance by a pyruvate-negative mutant of Clostridium saccharolyticum

Abstract

To improve the conversion of hexoses and pentoses to ethanol, a pyruvate-negative (PN) mutant of Clostridium saccharolyticum, having lower acetate kinase activity, was obtained. The PN mutant used more substrate (glucose or xylose) and produced more biomass and ethanol, but less acetic acid. This shift in catabolism raised the ethanol/acetate ratio from 6.7 to 13. The PN mutant converted both glucose and xylose to ethanol at an efficiency of 80% of the theoretical yield as compared to 64% for C. saccharolyticum wild type. This improved production of ethanol was also accompanied by an increased tolerance to ethanol. The PN mutant showed 50% growth inhibition at an ethanol concentration of 6.5% (v/v) as compared to 3.5% for the parent strain.

DOI: 10.1007/BF00500827

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Cite this paper

@article{Murray2004IncreasedEP, title={Increased ethanol production and tolerance by a pyruvate-negative mutant of Clostridium saccharolyticum}, author={William D. Murray and Kelly Wemyss and A. Waheed Khan}, journal={European journal of applied microbiology and biotechnology}, year={2004}, volume={18}, pages={71-74} }