Clostridium bovifaecis sp. nov., a novel acetogenic bacterium isolated from cow manure.

A strictly anaerobic, Gram-staining-positive, spore-forming rod-shaped bacterium, and designated BXX ^T , was isolated from cow manure. Colonies on DSMZ medium 311c agar plates were cream, circular, opaque and lustrous. Growth occurred at 20-45 °C with a pH range of 5.0-10.0 and at NaCl concentrations of up to 2 % (w/v). The optimum temperature, pH and NaCl concentration for growth were 30 °C, pH 7 and 1 % (w/v), respectively. The major cellular fatty acids were C16 : 0 (26.8 %), C14 : 0 (22.8 %), summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) (16.4 %) and C16 : 1ω9c (10.7 %). The main polar lipids of BXX ^T were diphosphatidylglycerol, phosphatidylethanolamine, unidentified aminolipids, an unidentified phospholipid and unidentified lipids. Acetate was mainly produced from H2/CO2, H2/CO2/CO (4/3/3, v/v/v), formate, glycerol, 1,2-propanediol, pyruvate, d-fructose and 2-methoxyethanol. BXX ^T is most closely related to Clostridium thermobutyricumDSM 4928 ^T , Clostridiumhomopropionicum DSM 5847 ^T and Clostridium thermopalmarium DSM 5974 ^T with 16S rRNA gene sequence similarities of 96.9, 96.6 and 96.5 %, respectively. The DNA G+C content of BXX ^T was 33.7 mol%, which was lower than that of C. thermobutyricum DSM 4928 ^T (37.0 mol%) and C. thermopalmarium DSM 5974 ^T (35.7 mol%). In addition, DSM 4928 ^T and DSM 5974 ^T are thermophilic members of the genus Clostridium. The absence of C15 : 0 also distinguished BXX ^T from Clostridium thermobutyricum. On the basis of phylogenetic, phenotypic and chemotaxonomic evidence, the novel isolate represents a novel species within the genus Clostridium, for which the name Clostridium bovifaecis sp. nov is proposed. The type strain of the type species is BXX ^T (=JCM 32382 ^T =CGMCC 1.5228 ^T ).