Hymenobacter mucosus sp. nov., isolated from a karst cave soil sample

Area of Science:

• Microbiology
• Bacterial Taxonomy
• Environmental Microbiology

Background:

• Soil ecosystems harbor diverse microbial communities.
• Cave environments present unique ecological niches for microbial adaptation.
• The genus Hymenobacter is known for its diverse metabolic capabilities and environmental distribution.

Purpose of the Study:

• To characterize a novel bacterial isolate from a cave soil sample.
• To determine the phylogenetic and chemotaxonomic properties of the isolate.
• To formally propose a new species within the Hymenobacter genus.

Main Methods:

• Isolation and cultivation of bacteria from soil.
• Gram staining, motility, and pigment analysis.
• 16S rRNA gene sequencing for phylogenetic analysis.
• Determination of growth conditions (temperature, pH, salinity).
• Chemotaxonomic analyses including menaquinone, fatty acid, and polar lipid profiling.
• Genomic DNA G+C content determination.

Main Results:

• A novel aerobic, Gram-negative, non-motile, rod-shaped bacterium with watermelon-red pigmentation was isolated (YIM 77969T).
• Phylogenetic analysis placed the isolate within the Hymenobacter genus, closely related to H. tibetensis, H. gelipurpurascens, and H. xinjiangensis.
• Optimal growth occurred between 5-35°C, pH 5.0-9.0, and 0-1% NaCl.
• Chemotaxonomic data (MK-7, specific fatty acids, polar lipids) and G+C content (55.2 mol%) supported its unique identity.
• The pigment was identified as belonging to the plectaniaxanthin series of carotenoids.

Conclusions:

• Strain YIM 77969T represents a novel species of the genus Hymenobacter.
• The proposed name for this new species is Hymenobacter mucosus sp. nov.
• The type strain is YIM 77969T (KCTC 32567T = DSM 28041T).