Bacillus tepidiphilus sp. nov., isolated from tepid spring.

Area of Science:

• Microbiology
• Bacteriology
• Taxonomy

Background:

• The genus Bacillus encompasses diverse bacterial species, some of which inhabit extreme environments.
• Understanding microbial diversity in unique habitats like hot springs is crucial for discovering novel microorganisms with unique properties.

Purpose of the Study:

• To characterize a novel Bacillus strain isolated from a tepid spring in China.
• To determine if the isolated strain represents a new species within the Bacillus genus.

Main Methods:

• Isolation and cultivation of bacteria from a tepid spring sediment sample.
• 16S rRNA gene sequencing for phylogenetic analysis.
• Physiological characterization including optimal growth conditions (pH, temperature, salinity).
• Chemotaxonomic analyses: cell-wall composition, isoprenoid quinones, and fatty acid profiles.
• Genomic DNA G+C content determination.
• Digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) calculations.

Main Results:

• A novel Bacillus strain, SYSU G01002T, was isolated and characterized.
• Phylogenetic analysis based on 16S rRNA showed highest similarity (97.7%) to Bacillus alkalitolerans.
• The strain exhibited thermophilic properties, growing optimally at 45°C and tolerating a wide pH range (6.0-8.0).
• Chemotaxonomic data and genomic analyses (dDDH and ANI values below thresholds) confirmed its distinction from known Bacillus species.

Conclusions:

• Strain SYSU G01002T represents a novel species within the genus Bacillus.
• The proposed name for this new species is Bacillus tepidiphilus sp. nov.
• This discovery expands the known diversity of thermophilic Bacillus species found in geothermal environments.