Rhizobium soli sp. nov., isolated from soil

Area of Science:

• Microbiology
• Bacteriology
• Taxonomy

Background:

• Soil bacteria play crucial roles in ecosystems.
• The genus Rhizobium comprises important nitrogen-fixing symbionts.
• Accurate bacterial classification is essential for understanding microbial diversity and function.

Purpose of the Study:

• To taxonomically characterize a novel bacterial isolate, strain DS-42(T), from Korean soil.
• To determine the phylogenetic and genetic relationship of strain DS-42(T) to known bacterial species.
• To propose a new species within the genus Rhizobium if the isolate represents a distinct taxon.

Main Methods:

• Polyphasic taxonomic study including phenotypic characterization.
• Phylogenetic analyses using 16S rRNA, atpD, and recA gene sequences.
• DNA-DNA hybridization for genetic relatedness assessment.

Main Results:

• Strain DS-42(T) is a Gram-negative, non-motile, rod-shaped bacterium.
• Phylogenetic analyses placed strain DS-42(T) within the genus Rhizobium.
• DNA-DNA relatedness values (13-19%) and phenotypic differences confirmed its distinction from related Rhizobium species.
• The DNA G+C content was 60.8 mol% with Q-10 as the predominant ubiquinone and C(18:1)ω7c as the major fatty acid.

Conclusions:

• Strain DS-42(T) represents a novel species of the genus Rhizobium.
• The proposed name for this new species is Rhizobium soli sp. nov.
• The type strain is DS-42(T) (=KCTC 12873(T) =JCM 14591(T)).