Bacillus arachidis sp. nov., Isolated from Peanut Rhizosphere Soil.

Abstract

A novel facultatively aerobic bacterium designated SY8 was isolated from a peanut rhizosphere soil sample collected in Jiangsu Province, China. Cells are Gram-stain-positive, rod-shaped, and agar colonies are creamy, opaque, and usually rhizoidal. Strain growth occurs at 30 - 45°C (optimum 30°C), pH 4.0 - 10.0 (optimum pH 6.0) and 0 - 4% (w/v) NaCl (optimum 2%) in Luria-Bertani medium. Phylogenetic analysis of the 16S rRNA gene sequences indicated that strain SY8 forms a distinct lineage in the clade of genus Bacillus and is related to Bacillus pseudomycoides DSM 12442T (99.9%). Phylogenetic analysis of the concatenated gene sequences of 16S rRNA, gryB and rpoD also indicated that strain SY8 forms a distinct lineage in Bacillus. Calculation of the average nucleotide identities and the digital DNA-DNA hybridization values between strain SY8 and the related type Bacillus strains further revealed that strain SY8 represents a distinct species. The predominant cellular fatty acids are iso C15:0 (28.7%) and summed feature 3 (C16:1ω7c and/or C16:1ω6c) (10.3%). The major polar lipids consisted of diphosphatidyl glycerol, phosphatidyl glycerol, phosphatidyl ethanolamine, phosphatidylinositol, and three unidentified phospholipids. The major menaquinone of SY8 was MK-7. Based on phenotypic, phylogenetic, chemotaxonomic, and genomic features, strain SY8 represents a novel species of the genus Bacillus. The name Bacillus arachidis sp. nov. is proposed with strain SY8T (= CCTCC AB 2021100T=LMG 32409T) designated as the type strain.