Thermophilic degradation of cellulose by a triculture of CLOSTRIDIUM THERMOCELLUM, METHANOBACTERIUM sp. and METHANOSARCINA MP (Methanogenesis ; defined mixed culture)

The fermentation of cellulose at 55°C by different associations of the 3 bacteria CLOSTRIDIUM THERMOCELLUM, METHANOBACTERIUM sp. and METHANOSARCINA MP, was studied. C. THERMOCELLUM alone produced acetate, lactate, ethanol, H2 and CO2. The co-culture C. THERMOCELLUM-METHANOBACTERIUM sp. produced more acetate and less ethanol than the monoculture of CLOSTRIDIUM. METHANOSARCINA MP used acetate only in the triculture including METHANOBACTERIUM sp. When methanol was added (5 mM) to the triculture, METHANOSARCINA MP had a shorter lag phase on acetate and degraded much more acetate. Maximum methane production was 8.5 mmol CH4/g cellulose degraded. (Résumé d'auteur