Spirosoma lituiforme sp. nov., isolated from soil

Area of Science:

• Microbiology
• Bacteriology
• Taxonomy

Background:

• Soil microbial communities harbor diverse bacterial species with unique ecological roles.
• Accurate taxonomic classification is crucial for understanding bacterial diversity and function.
• The genus Spirosoma comprises aerobic, Gram-negative bacteria with diverse environmental distributions.

Purpose of the Study:

• To taxonomically characterize a novel bacterial isolate from Korean soil.
• To determine the phylogenetic and chemotaxonomic relationship of the isolate to known bacteria.
• To propose a new species designation for the novel isolate within the genus Spirosoma.

Main Methods:

• Polyphasic taxonomic characterization including 16S rRNA gene sequencing.
• Analysis of genomic DNA G+C content, major fatty acids, polar lipids, and respiratory quinones.
• DNA-DNA hybridization for assessing genetic relatedness to closely related species.

Main Results:

• Strain S1-2-4^T, a Gram-negative, non-motile, curved rod-shaped, aerobic bacterium, was isolated.
• 16S rRNA gene sequence analysis placed the isolate within the family Cytophagaceae, closely related to Spirosoma species.
• Chemotaxonomic data (fatty acids, polar lipids, quinones) and low DNA-DNA relatedness (31% with 'Spirosoma radiotolerans') supported its distinctiveness.

Conclusions:

• Strain S1-2-4^T represents a novel species within the genus Spirosoma, proposed as Spirosoma lituiforme sp. nov.
• The distinct phenotypic, genotypic, and chemotaxonomic features differentiate it from known Spirosoma species.
• This finding contributes to the understanding of bacterial diversity in soil ecosystems.