Corynebacterium defluvii sp. nov., isolated from Sewage

Area of Science:

• Microbiology
• Bacteriology
• Taxonomy

Background:

• The genus Corynebacterium comprises diverse Gram-positive bacteria with significant industrial and clinical relevance.
• Accurate bacterial classification is crucial for understanding microbial ecology and developing biotechnological applications.

Purpose of the Study:

• To isolate and characterize a novel bacterial strain from a sewage environment.
• To determine the taxonomic position of the novel strain Y49^T within the genus Corynebacterium through polyphasic analysis.

Main Methods:

• Isolation and cultivation of strain Y49^T from sewage.
• Physiological and biochemical characterization, including growth conditions and enzymatic activities.
• Chemotaxonomic analyses: fatty acid profiling, isoprenoid quinone analysis, polar lipid composition, and cell-wall peptidoglycan analysis.
• Phylogenetic analysis based on 16S rRNA gene sequencing.
• DNA-DNA hybridization for genetic relatedness assessment.

Main Results:

• Strain Y49^T is a Gram-positive, aerobic, non-motile, rod-shaped bacterium.
• Optimal growth occurred at 30°C, pH 7.0, and 0% NaCl.
• Chemotaxonomic data revealed menaquinone-8 (MK-8) as the major isoprenoid quinone and meso-diaminopimelic acid in the peptidoglycan.
• 16S rRNA gene sequence analysis showed highest similarity to Corynebacterium efficiens (97.5%).
• DNA-DNA hybridization values were below 25.5% with closely related Corynebacterium species, indicating distinctness.
• DNA G+C content was 51.4 mol%.

Conclusions:

• Strain Y49^T represents a novel species within the genus Corynebacterium.
• The proposed name for this new species is Corynebacterium defluvii sp. nov.
• The type strain is Y49^T (= KCTC 39731^T = CGMCC 1.15506^T).