Bacillus oceani sp. nov., isolated from seawater

Area of Science:

• Microbiology
• Bacterial Taxonomy
• Marine Biology

Background:

• Isolation of novel bacterial strains from diverse environments is crucial for understanding microbial diversity.
• The Indian Ocean, a vast marine ecosystem, remains a rich source for discovering new microorganisms with unique properties.
• The genus *Bacillus* comprises diverse species, many with industrial and biotechnological applications.

Purpose of the Study:

• To characterize and classify two novel bacterial strains, SW109^T and W006, isolated from an Indian Ocean seawater sample.
• To determine the phylogenetic and phenotypic characteristics of these strains to ascertain their taxonomic position.
• To propose a new species within the genus *Bacillus* based on comprehensive analysis.

Main Methods:

• Gram staining, endospore formation, and cellular morphology observation.
• Aerobic cultivation, catalase and oxidase activity tests, and motility assessment.
• Predominant cellular fatty acid analysis, menaquinone profiling, and polar lipid determination.
• Genomic DNA G+C content determination.
• Phylogenetic analysis using 16S rRNA gene sequences.

Main Results:

• Strains SW109^T and W006 are Gram-positive, endospore-forming, aerobic, motile rods.
• Key chemotaxonomic features include anteiso-C_15:0, iso-C_15:0, iso-C_14:0 fatty acids, MK-7, and specific polar lipids.
• Genomic DNA G+C content was approximately 46.1-46.3 mol%.
• Phylogenetic analysis based on 16S rRNA gene sequences showed highest similarity (96.4%) to *Bacillus halodurans* LMG 7121^T.
• The strains represent a distinct lineage within the genus *Bacillus*.

Conclusions:

• The two strains, SW109^T and W006, are phenotypically and phylogenetically distinct from known *Bacillus* species.
• Based on integrated polyphasic taxonomic data, the strains represent a novel species of the genus *Bacillus*.
• The proposed name for this new species is *Bacillus oceani* sp. nov., with strain SW109^T as the type strain.