Nocardioides paucivorans sp. nov. isolated from soil

Area of Science:

• Microbiology
• Bacteriology
• Taxonomy

Background:

• Soil microorganisms play crucial roles in ecosystem functions.
• The genus Nocardioides comprises diverse Gram-positive bacteria with various metabolic capabilities.
• Exploring novel bacterial isolates from unique environments like Dokdo Island contributes to understanding microbial diversity.

Purpose of the Study:

• To characterize and classify a newly isolated bacterial strain from a soil sample.
• To determine the taxonomic position of the strain KIS31-44(T) within the genus Nocardioides.
• To propose a new species designation based on polyphasic taxonomic data.

Main Methods:

• Isolation and cultivation of bacteria from soil samples.
• Gram staining, assessment of motility, spore formation, and optimal growth conditions (temperature, pH, salinity).
• 16S rRNA gene sequencing for phylogenetic analysis, chemotaxonomic analyses (fatty acids, isoprenoid quinones, polar lipids), and peptidoglycan analysis.

Main Results:

• Strain KIS31-44(T) is a Gram-stain-positive, aerobic, non-spore-forming, non-motile bacterium.
• Phylogenetic analysis based on 16S rRNA gene sequences indicated its affiliation with the genus Nocardioides, with highest similarity to Nocardioides aestuarii JC2056(T) (95.5%) and Nocardioides terrae VA15(T) (95.0%).
• Chemotaxonomic data, including major fatty acids, isoprenoid quinone (MK-8 (H₄)), polar lipids, and peptidoglycan structure (A3γ-type with LL-diaminopimelic acid), supported its distinct taxonomic status.

Conclusions:

• The data collectively support the classification of strain KIS31-44(T) as a representative of a novel species within the genus Nocardioides.
• The proposed name for this new species is Nocardioides paucivorans sp. nov.
• The type strain is KIS31-44(T), also designated as DSM 27142(T) and KACC 17309(T).