Lysinibacillus antri sp. nov., isolated from cave soil

Area of Science:

• Microbiology
• Bacterial Taxonomy
• Environmental Microbiology

Background:

• Soil microbial communities harbor diverse bacterial species.
• Karst cave environments are unique ecosystems with potential for novel microbial discoveries.
• The genus Lysinibacillus comprises Gram-positive, endospore-forming bacteria with various ecological roles.

Purpose of the Study:

• To isolate and characterize a novel bacterial strain from a karst cave soil sample.
• To determine the taxonomic affiliation of the novel strain using polyphasic characterization.
• To propose a new species within the Lysinibacillus genus.

Main Methods:

• Isolation and cultivation of bacteria from soil samples.
• Phenotypic characterization including Gram staining, motility, and growth conditions (temperature, pH, NaCl tolerance).
• Chemotaxonomic analyses: cell-wall peptidoglycan type, cell-wall sugars, menaquinone, fatty acid profiles, and polar lipids.
• Genomic analysis: DNA G+C content determination and average nucleotide identity (ANI) calculations.

Main Results:

• A Gram-positive, motile, rod-shaped, endospore-forming bacterium, strain SYSU K30002^T, was isolated.
• Optimal growth occurred at 37°C, pH 7.0, and without added NaCl.
• Chemotaxonomic data revealed specific cell-wall components, major fatty acids, and polar lipids.
• Genomic analysis showed a G+C content of 36.1 mol% and ANI values below the species delineation threshold (<95-96%) with related Lysinibacillus species.

Conclusions:

• Strain SYSU K30002^T represents a novel species of the genus Lysinibacillus based on integrated phenotypic, chemotaxonomic, and genomic data.
• The proposed name for this new species is Lysinibacillus antri sp. nov.
• The type strain is SYSU K30002^T (=KCTC 33955^T=CGMCC 1.13504^T).