A Gram-positive, spore-forming, motile rod-shaped bacterium, designated strain Y27T, was isolated from the bottom of a mold fermenter used in the process of soy sauce production. Phylogenetic analysis of the 16S rRNA gene sequence from this strain placed it within the genus Oceanobacillus, and further sequence analysis revealed that this strain has a sequence similarity of 95.0-98.7% to other known species of Oceanobacillus. The DNA-DNA relatedness between strain Y27T and related type strains of the genus Oceanobacillus is below 43%, indicating that it should be considered a separate species. Characterization of strain Y27T revealed that the major cellular fatty acid is anteiso-C(15:0), the cell wall contains meso-diaminopimelic acid-type peptidoglycans, the major menaquinone is MK-7, and the major polar lipids are diphosphatidylglycerol and phosphatidylglycerol. The genomic DNA G+C content of the strain is 38.0 mol%. On the basis of these phylogenetic, physiological and chemotaxonomic data, we propose that this isolate represents a novel species of the genus Oceanobacillus, and propose the name Oceanobacillus soja sp. nov. The type strain is strain Y27T (= JCM 15792T = NRRL B-59181T = NBRC 105379T = NCIMB 14542T).