Bacillus pakistanensis sp. nov., a halotolerant bacterium isolated from salt mines of the Karak Area in Pakistan.

Abstract

A rod shaped, non-motile, endospore forming, Gram-stain positive and moderately halotolerant strain, designated as NCCP-168(T), was isolated from salt mines sampled in the Karak district of Khyber Pakhtunkhwa Province in Pakistan. To delineate its taxonomic position, the strain was subjected to polyphasic characterization. Cells of strain NCCP-168(T) can grow at 10-40(○)C (optimum at 30-35(○)C), in a pH range of 5.0-9.0 (optimum at pH 8.0) and in 0-17% (w/v) NaCl on agar medium. The phylogenetic analysis based on the 16S rRNA gene sequence showed that strain NCCP-168(T) belongs to the genus Bacillus with the highest similarity to Bacillus seohaeanensis BH724(T) (97.1%), and less than 97% similarity with other closely related taxa (95.6% with B. subtilis subsp. subtilis NCIB3610(T)). DNA-DNA relatedness between strain NCCP-168(T) and the type strains of closely related species was lower than 30%. Chemotaxonomic data (major menaquinone, MK-7; cell wall peptidoglycan type, A1γ [meso-diaminopimelic acid]; major fatty acids, iso-C15:0 29.9%, anteiso-C15:0 29.3%, iso-C16:0 11.4%, iso-C14:0 8.9% and anteiso-C17:0 7.0%; major polar lipids, diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine) support the affiliation of strain NCCP-168(T) with genus Bacillus. On the basis of phenotypic, chemotaxonomic and phylogenetic data, strain NCCP-168(T) can be distinguished from the closely related taxa and thus represents a novel species in the genus Bacillus, for which the name Bacillus pakistanensis sp. nov. is proposed, with the type strain NCCP-168(T) (=KCTC 13786(T)=DSM 24834(T)=JCM 18975(T)).