Two cellulolytic Clostridium species: Clostridium cellulosi sp. nov. and Clostridium cellulofermentans sp. nov.

Two cellulolytic clostridia, one thermophilic and the other mesophilic, were isolated and characterized. Cells of the thermophile are gram-negative rods that are motile with lophotrichous flagella and spherical terminal endospores which swell the cells. The optimum growth temperature is 55 to 60 degrees C, with a range of 40 to 65 degrees C. The deoxyribonucleic acid composition is 35 mol% G + C. The name Clostridium cellulosi sp. nov. is proposed. The type strain is AS 1.1777. Cells of the mesophile are gram negative and motile with peritrichous flagella and terminal oval or spherical spores which swell the cells. The deoxyribonucleic acid composition is 34 mol% G + C. The name Clostridium cellulofermentans sp. nov. is proposed. The type strain is AS 1.1775. Both C. cellulosi AS 1.1777 and C. cellulofermentans AS 1.1775 are deposited in the China Committee for Culture Collection of Microorganisms, Institute of Microbiology, Academia Sinica, Beijing, People's Republic of China.