Hymenobacter sedentarius sp. nov., isolated from a soil

Area of Science:

• Microbiology
• Bacteriology
• Environmental Science

Background:

• Soil ecosystems harbor diverse microbial communities.
• The genus Hymenobacter, belonging to the class Cytophagia, is known for its presence in various environments.
• Characterization of novel bacterial species is crucial for understanding microbial diversity and function.

Purpose of the Study:

• To isolate and characterize a novel bacterium from dry soil.
• To determine the taxonomic position of the isolate using phenotypic, chemotaxonomic, and genotypic data.
• To propose a new species within the genus Hymenobacter.

Main Methods:

• Isolation of bacteria from dry soil.
• Gram staining, motility tests, and growth condition analysis (temperature, pH).
• 16S rRNA gene sequencing for phylogenetic analysis.
• DNA-DNA hybridization for genomic relatedness.
• Chemotaxonomic analysis including fatty acid profiling, polar lipid analysis, and quinone determination.
• Pigment analysis and gamma-ray irradiation resistance testing.

Main Results:

• A novel Gram-negative, red-pinkish, non-motile bacterium, designated DG5B(T), was isolated.
• Phylogenetic analysis based on 16S rRNA gene sequences placed DG5B(T) within the genus Hymenobacter.
• DNA-DNA relatedness values were below 70% with closely related species, confirming it as a distinct genomic species.
• Chemotaxonomic data, including major fatty acids (iso-C15:0, anteiso-C15:0, C16:1 ω5c, summed feature 3) and MK-7 as the major quinone, supported its classification.
• The strain exhibited low-level resistance to gamma-ray irradiation.

Conclusions:

• The phenotypic, chemotaxonomic, and genotypic properties clearly distinguish DG5B(T) as a novel species.
• Hymenobacter sedentarius sp. nov. is proposed as the name for this new species.
• The type strain is DG5B(T) (=KCTC 32524(T) =JCM 19636(T)).