Sphingobacterium arenae sp. nov., isolated from sandy soil

Area of Science:

• Microbiology
• Bacteriology
• Taxonomy

Background:

• Soil ecosystems harbor diverse microbial communities.
• The genus Sphingobacterium comprises Gram-negative bacteria with various ecological roles.
• Accurate bacterial classification is crucial for understanding microbial diversity and function.

Purpose of the Study:

• To characterize a novel bacterial isolate from a Chinese soil sample.
• To determine the taxonomic position of the isolate within the genus Sphingobacterium.
• To formally propose a new species and type strain.

Main Methods:

• Isolation and cultivation of the bacterial strain H-12(T).
• Physicochemical characterization including growth conditions (temperature, pH, salinity).
• Molecular phylogenetic analysis using 16S rRNA gene sequencing.
• DNA-DNA hybridization for genetic relatedness assessment.
• Analysis of chemotaxonomic markers (quinone, polar lipids, fatty acids) and DNA G+C content.

Main Results:

• Strain H-12(T) is a Gram-negative, aerobic, non-motile, non-spore-forming rod.
• Optimal growth observed at 30 °C and pH 8.5, tolerating 0-5% NaCl.
• 16S rRNA gene sequence similarity of 90.0% to Sphingobacterium composti.
• Low DNA-DNA relatedness (45.5%) to S. composti, indicating a distinct species.
• Unique chemotaxonomic profile with MK-7 as the predominant quinone and specific fatty acid composition.
• DNA G+C content determined to be 44.15 mol%.

Conclusions:

• Strain H-12(T) represents a novel species within the genus Sphingobacterium.
• The proposed name for this new species is Sphingobacterium arenae sp. nov.
• The type strain is designated H-12(T) (ACCC 05758(T) = KCTC 32294(T)).