Extracellular glycosyl hydrolase activity of the clostridia producing acetone, butanol, and ethanol

Production of acetone, butanol, ethanol, acetic acid, and butyric acid by three strains of anaerobic bacteria, which we identified as Clostridium acetobutylicum, was studied. The yield of acetone and alcohols in 6% flour medium amounted to 12.7-15 g/l with butanol constituting 51.0-55.6%. Activities of these strains towards xylan, beta-glucan, carboxymethylcellulose, and crystalline and amorphous celluloses were studied. C. acertobutylicum 6, C. acetoburylicum 7, and C. acertobutylicum VKPM B-4786 produced larger amounts of acetone and alcohols and displayed higher cellulase and hemicellulase activities than the type strain C. acetobutylicum ATCC 824. It was demonstrated that starch in the medium could be partially substituted with plant biomass.