CLOSTRIDIUM HERBIVORANS SP-NOV, A CELLULOLYTIC ANAEROBE FROM THE PIG INTESTINE

A new cellulolytic anaerobic clostridium was isolated from the intesti nal tract of pigs, The single isolate was a gram-positive, motile rod, formed terminal to subterminal swollen sporangia, and required a ferm entable carbohydrate for growth, Cellulose, cellobiose, maltose, starc h, and glycogen supported growth, but glucose and fructose did not, Th e major end products from the fermentation of cellobiose were butyrate and formate; minor amounts of hydrogen and ethanol were also formed, Ruminal fluid (15%) or yeast extract (1%) was required for good growth . The optimum temperature for growth was 39 to 42 degrees C, and the o ptimum pH was 6.8 to 7.2, Cell lysis occurred rapidly once stationary growth was reached, A 16S rRNA sequence analysis showed that the strai n was related to a group of gram-positive anaerobes that includes Clos tridium oroticum and the cellulolytic species Clostridium polysaccharo lyticum and Clostridium populeti, The DNA base composition of the isol ate is 38 mol% G + C. We propose the name Clostridium herbivorans for this organism; strain 54408 (= ATCC 49925) is the type strain.