A novel Gram-staining-positive, moderately halophilic, facultatively alkaliphilic, non-motile, catalase-positive, oxidase-negative, endospore-forming, facultatively anaerobic rod, designated JSM 076093(T), was isolated from a sea urchin (Hemicentrotus pulcherrimus) collected from Naozhou Island in the South China Sea. Growth occurred with 0.5-25% (w/v) NaCl (optimum 5-8%) and at pH 6.0-10.5 (optimum pH 8.0) and 5-40 °C (optimum 30-35 °C). meso-Diaminopimelic acid was present in the cell-wall peptidoglycan. The predominant respiratory quinone was menaquinone 7 and the polar lipids consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and one unidentified phospholipid. The major cellular fatty acids (>10% of the total) were anteiso-C(15:0), anteiso-C(17:0), iso-C(16:0) and iso-C(14:0). The genomic DNA G+C content was 38.8 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain JSM 076093(T) belonged to the genus Bacillus and was related most closely to Bacillus hwajinpoensis SW-72(T) (99.1% 16S rRNA gene sequence similarity) and Bacillus algicola KMM 3737(T) (97.3%). The combination of results from the phylogenetic analysis, DNA-DNA hybridization and phenotypic and chemotaxonomic characterization supported the conclusion that strain JSM 076093(T) represents a novel species of the genus Bacillus, for which the name Bacillus hemicentroti sp. nov. is proposed, with JSM 076093(T) (=DSM 23007(T)=KCTC 13710(T)) as the type strain.