Bacillus krulwichiae sp. nov., a halotolerant obligate alkaliphile that utilizes benzoate and m-hydroxybenzoate

Obligate alkaliphilic strains, AM31D and AM11D, that utilize benzoate and m-hydroxybenzoate were isolated from soil obtained from Tsukuba, Ibaralki, Japan. The isolates grew at pH 8-10, but not at neutral pH. They were Gram-positive, facultatively anaerobic, straight rods with peritrichous flagella and produced ellipsoidal spores. The isolates reduced nitrate to nitrite and grew in 0-14% NaCl, but not in higher concentrations. The major isoprenoid quinones were menaquinone-5, -6 and -7, and the cellular fatty acid profile consisted of significant amounts of 15-C branched-chain acids, isoC and anteisoC. Phylogenetic analysis based on 16S rRNA gene sequencing indicated that strain AM31D was a member of group 6 (alkaliphiles) in the genus Bacillus. DNA-DNA hybridization revealed a low relatedness of the isolates with several phylogenetically close neighbours, including Bacillus alcalophilus and Bacillus pseudalcaliphilus (less than 19.3%). Based on phenotypic characteristics, phylogenetic data and DNA-DNA relatedness data, it was concluded that these isolates merited classification as a new species, for which the name Bacillus krulwichiae is proposed. The type strain of this species is AM31D (=NCIMB 13904=JCM 11691=IAM 15000).