Loktanella variabilis sp. nov., isolated from a tidal flat

Area of Science:

• Microbiology
• Bacteriology
• Taxonomy

Background:

• Marine environments harbor diverse microbial communities.
• Bacterial taxonomy relies on phenotypic and genotypic characterization.
• The genus Loktanella comprises Gram-negative bacteria with varied ecological roles.

Purpose of the Study:

• To isolate and characterize novel bacterial strains from a South Korean tidal flat.
• To determine the taxonomic position of two distinct bacterial isolates.
• To propose a new species within the genus Loktanella.

Main Methods:

• Isolation and cultivation of bacterial strains.
• 16S rRNA gene sequencing for phylogenetic analysis.
• DNA-DNA hybridization for genetic relatedness assessment.
• Fatty acid and polar lipid profile analysis.
• Determination of DNA G+C content.

Main Results:

• Two strains, J-MR2-Y(T) and J-MR2-O, were isolated and showed high 16S rRNA gene sequence similarity (97.83-99.06%) to known Loktanella species.
• DNA-DNA relatedness between the novel strains and type strains of related species was low (19-37%).
• The strains possessed characteristic ubiquinone (Q-10), major fatty acid (C(18:1)ω7c), and polar lipid profiles.
• DNA G+C content was determined to be 68.1-68.4 mol%.

Conclusions:

• The novel strains J-MR2-Y(T) and J-MR2-O are phenotypically and genotypically distinct from other recognized Loktanella species.
• The data support the classification of these strains as a new species, Loktanella variabilis sp. nov.
• The type strain is J-MR2-Y(T) (KCTC 42074(T) = CECT 8572(T)).