Bacillus horti sp. nov., a new Gram-negative alkaliphilic bacillus

Abstract

Novel Gram-negative alkaliphilic strains were isolated from soil obtained from Atsuma, Hokkaido, Japan. The isolates were strictly aerobic rods that produced subterminally located ellipsoidal spores. Chemotaxonomic characteristics of the isolates included the presence of meso-diaminopimelic acid in the cell wall and a DNA G+C content of 40·2–40·9 mol%. The major isoprenoid quinone was menaquinone-7 and the cellular fatty acid profile consisted of a significant amount of 15-C branched-chain acids, iso-C_15:0 and anteiso-C_15:0. The growth rate was higher at pH 8–10 than at pH 7. Comparative sequence analysis of 16S rDNA of 14 alkaliphilic Bacillus strains indicates that the isolated strain has an equidistant relationship to three already defined rRNA groups of alkaliphilic Bacillus species. Based on the morphological and physiological characteristics, as well as phylogenetic position as determined by 16S rDNA analysis and DNA-DNA relatedness data, it is concluded that these isolates should be designated as a new species, for which the name Bacillus horti is proposed. The type strain is K13^T(= JCM 9943^T).