The fermentation of cellulose by thermophilic bacteria

Abstract

1. A thermophilic organism which destroys cellulose at 65° C. has been isolated in pure culture.2. The organism is motile, gram negative, forms spores in the swollen end, stains well with carbol fuchsin, poorly with methylene blue.3. After growth on media without cellulose the organism is unable to ferment cellulose.4. The range of fermentation is from 43° C. to 65° C. The organism lives at 38° C. and 72° C. but does not ferment at these temperatures.5. The spores are very resistant to heat and withstand 115° C. for 35 minutes.6. Heating the spores to 100° C. for 5 to 10 minutes causes an increased rate of germination.7. Carbohydrates fermented: cellulose, starch, raffinose, sucrose, maltose, lactose, mannose, galactose, fructose, glucose, xylose and arabinose.8. Organic nitrogen is necessary for the fermentation, and peptone is the best source.9. The products from cellulose are: acetic acid, small amounts of butyric acid, ethyl alcohol, carbon dioxide and hydrogen. The amount of cellulose destroyed in a 1 to 5 per cent, suspension varies from 70 to 95 per cent. Of the cellulose destroyed, 50 to 55 per cent, is regained as acetic acid, 5 to 25 per cent. as ethyl alcohol and the rest as small amounts of butyric acid, carbon dioxide, hydrogen, and pigment. The pigment is a fatty substance soluble in ether.