Abstract
A new strictly anaerobic, alkaliphilic, moderately thermophilic, fermentative, spore-forming bacterium, strain K1(T), was isolated from manure samples (pH 6.8). Cells were Gram-positive, straight, non-motile rods that grew at temperatures of 37--66 degrees C (optimum at 62 degrees C) and in a pH range of 8.0--10.5 (optimum at 9.5--9.7). The bacterium fermented D-glucose, sucrose, D-fructose, D-trehalose and starch as carbon and energy sources. It required vitamins and its growth is stimulated by yeast extract. The major metabolic products were H(2) and acetate. Cells were catalase-negative and could reduce nitrate to nitrite. The G+C content of the DNA was 42.2 mol%. Based on the phenotypic properties and 16S rDNA sequencing and DNA--DNA hybridization data, strain K1(T) (=DSM 12423(T)=ATCC 700785(T)=VKM B-2193(T)) was assigned to the new genus Anoxybacillus gen. nov., as a representative of a new species, Anoxybacillus pushchinensis sp. nov. 'Bacillus flavothermus' strain d.y., which was found to be closely related to strain K1(T), is described as Anoxybacillus flavithermus comb. nov. (type strain=d.y.(T)=DSM 2641(T)).