Salinibacterium soli sp. nov., isolated from lakeside soil

Area of Science:

• Microbiology
• Bacteriology
• Phylogenetics
• Taxonomy

Background:

• The family Microbacteriaceae encompasses diverse bacteria with significant ecological roles.
• The genus Salinibacterium currently includes species with unique adaptations, necessitating further exploration.
• Characterization of novel bacterial strains is crucial for understanding microbial evolution and biodiversity.

Purpose of the Study:

• To characterize a novel bacterial isolate, strain WY-16^T, phenotypically and genotypically.
• To determine the phylogenetic placement of strain WY-16^T within the Microbacteriaceae family.
• To propose a new species and genus for strain WY-16^T based on comprehensive data.

Main Methods:

• Isolation and cultivation of strain WY-16^T under varying environmental conditions (temperature, pH, salinity).
• Gram staining, morphological, and biochemical characterization.
• Genomic sequencing for phylogenetic analysis, including average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) calculations.
• Analysis of cellular fatty acids, menaquinones, polar lipids, and cell-wall peptidoglycan composition.

Main Results:

• Strain WY-16^T is a Gram-positive, rod-shaped, non-spore-forming, non-motile bacterium with optimal growth at 30°C, pH 7, and 1% salinity.
• Phylogenetic analysis placed WY-16^T within the family Microbacteriaceae, closely related to Salinibacterium xinjiangense and Salinibacterium amurskyense, but with ANI and dDDH values below species delineation thresholds.
• Unique chemotaxonomic features including specific fatty acid profiles (anteiso-C15:0, iso-C16:0, iso-C16:0 10-methyl), major menaquinones (MK-12 to MK-15), polar lipids, and cell-wall peptidoglycan (2,4-diaminobutyric acid) were identified.

Conclusions:

• Strain WY-16^T represents a novel species within the genus Salinibacterium, proposed as Salinibacterium soli sp. nov.
• The findings contribute to the taxonomic classification and understanding of the genus Salinibacterium.
• The type strain is WY-16^T (=GDMCC 1.4011^T=JCM 36421^T).