Bacillus depressus sp. nov., isolated from soil of a sunflower field

A Gram-stain positive, rod-shaped, endospore-forming and aerobic bacterium, designated BZ1T, was isolated from a soil sample collected from a sunflower field in Wuyuan county, Inner Mongolia, China. On the basis of 16S rRNA gene sequence analysis, the isolate was found to be a member of the genus Bacillus and the close phylogenetic relatives to be Bacillus gottheilii WCC 4585T, Bacillus oceanisediminis H2T, Bacillus mesonae FJAT-13985T and Bacillus horneckiae DSM 23495T with 98.3, 98.1, 98.0 and 97.6 % sequence similarity, respectively. Strain BZ1T was found to grow at 6–40 °C (optimum 30–33 °C), pH 6.0-9.0 (optimum pH 7.0) and 0–5.5 % (w/v) NaCl (optimum 0.5 %). The cell wall diamino acid of the peptidoglycan of strain BZ1T was identified as meso-diaminopimelic acid and the predominant respiratory quinone as MK-7. The major cellular fatty acids were found to be iso-C15:0, anteiso-C15:0 and iso-C14:0, and the polar lipids to consist of diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The novel strain was found to have a DNA G + C content 44.5 mol%. DNA–DNA hybridization with closely related strains was low. Based on phenotypic, phylogenetic and chemotaxonomic results, it is concluded that strain BZ1T represents a novel species within the genus Bacillus, for which we propose the name Bacillus depressus sp. nov. The type strain is BZ1T (= CGMCC 1.15124T = KCTC 33643T).