Brevibacillus dissolubilis sp. nov., Isolated from Fresh Water

Area of Science:

• Microbiology
• Bacterial Taxonomy
• Genomics

Background:

• The genus Brevibacillus comprises spore-forming bacteria with diverse metabolic capabilities.
• Accurate bacterial classification is crucial for understanding microbial ecology and potential applications.
• Previous studies have explored Brevibacillus species isolated from various environmental niches.

Purpose of the Study:

• To isolate and characterize a novel bacterial strain from the Chishui River.
• To determine the taxonomic position of the novel strain using polyphasic characterization, including 16S rRNA gene sequencing and whole-genome analysis.
• To propose a new species within the Brevibacillus genus.

Main Methods:

• Isolation and cultivation of bacterial strain CHY01 from river sediment.
• Phylogenetic analysis based on 16S rRNA gene sequences.
• Determination of chemotaxonomic properties (respiratory quinone, polar lipids, fatty acids).
• Genome sequencing and analysis, including G+C content and average nucleotide identity (ANI).
• Phenotypic and biochemical testing for differentiation from related species.

Main Results:

• Strain CHY01 is a Gram-positive, strictly aerobic, motile, endospore-forming bacterium.
• 16S rRNA gene sequence analysis showed 97.8% similarity to Brevibacillus panacihumi.
• Chemotaxonomic data included MK-7 as the predominant respiratory quinone and phosphatidylethanolamine and phosphatidylglycerol as major polar lipids.
• Genome size was 6.1 Mbp with a G+C content of 50.6%.
• ANI and digital DNA-DNA hybridization (dDDH) values supported the designation of a new species.

Conclusions:

• Strain CHY01 represents a distinct genotypic and phenotypic lineage within the Brevibacillus genus.
• The proposed name Brevibacillus dissolubilis sp. nov. reflects its unique characteristics.
• This finding expands the known diversity of the Brevibacillus genus and highlights the microbial richness of the Chishui River ecosystem.