The Culture and Physiology of a Thermophilic Cellulose-fermenting Bacterium

Abstract

Thermophilic cellulose-fermenting bacteria from soil and manure were pure cultured by a method which permitted the picking of isolated colonies from shake tubes containing cellulose or cellobiose agar. The quantitatively detd. products of cellulose fermentation at 55 C were CO2, H2, ethanol, glycerol, formic, acetic, lactic, and succinic acids, accounting for approx. 70% of the C of the cellulose. Compounds containing the other 30% were not identified. CH4 and higher alcohols and acids were not present. Reducing sugars were not formed during fermentation but accumulated due to hydrolysis in old cultures containing an excess of cellulose. Glucose and cellobiose were identified. Cellobiose was fermented but glucose was not. The enzymes cellulase and cellobiase were both normally present when the substrate was cellulose.