STUDIES ON A THERMOPHILIC ANAEROBIC CELLULOLYTIC MICROBIAL COMMUNITY

A thermophilic, anaerobic, cellulolypic static culture has been established which has been actively degrading cellulose for four years, and this cellulolytic methane producing community appears to have a complete recycling capacity.;The cellulase (especially endoglucanase) of C22225 is isolated and studied. Glucose, the main hydrolytic product from cellulose acts as a catabolite repressor on endoglucanase activity. Endoglucanase from C22225 is isolated as a complex or aggregate. The endoglucanase activity can be renatured after the SDS molecules are removed from the SDS-polyacrylamide gel, and the molecular weight of endoglucanase is 52,500 as measured by SDS-polyacrylamide gel electrophoresis.;The defined coculture of C22225 and glucose isolant from the view point of ethanol production is also studied. The incubation time for cellulose isolant C22225, i.e., 2 days, and the inoculum size of the glucose isolant, i.e., 2% are important in terms of higher yield of ethanol with the coculture fermentation.;Pure cellulose, glucose, xylose, mannitol and acetate utilizing cultures have been isolated. The monosaccharide isolants and acetate isolant have optimal pH of 5.5 for growth. The cellulolytic isolant (C22225) has a pH optimum of 8.5 for growth. Some physiological characteristics of the monosaccharide isolants and acetate isolant are evaluated, and they appear to be at least strain variants if not different species. The cellulolytic isolant C22225 is a gram-negative spore-former resembling Clostridium thermocellum, but with an optimal pH for growth of 8.5, rather that 7.5.