Showing papers on "Methanogen published in 1975"

Fermentation of cellulose and cellobiose by 'Clostridium thermocellum' in the absence and presence of 'Methanobacterium thermoautotrophicum'. (Thermophilic cellulose fermentation)

Abstract: The fermentation of cellulose and cellobiose by Clostridium thermocellum monocultures and C. thermocellum/Methanobacterium thermoautotrophicum cocultures was studied. All cultures were grown under anaerobic conditions in batch culture at 60C. When grown on cellulose, the coculture exhibited a shorter lag before initiation of growth and cellulolysis than did the monoculture. Monocultures produced primarily ethanol, acetic acid, H2, and CO2. Cocultures produced more H2 and acetic acid and less ethanol than did the monoculture. In the coculture, conversion of H2 to methane was usually complete, and most of the methane produced was derived from CO2 reduction rather than from acetate conversion. Agents of fermentation stoppage were found to be toxic concentrations of ethanol and acid in the monoculture and of acid in the coculture. Fermentation of cellobiose was more rapid than that of cellulose. In cellobiose medium, the methanogen caused only slight changes in the fermentation balance of the Clostridium, and free H2 was produced.