Hymenobacter arcticus sp. nov., isolated from glacial till

Area of Science:

• Microbiology
• Arctic microbiology
• Bacterial taxonomy

Background:

• The genus Hymenobacter comprises Gram-negative bacteria found in diverse environments.
• Arctic regions harbor unique microbial communities shaped by extreme conditions.
• Characterization of novel bacteria is crucial for understanding microbial diversity and adaptation.

Purpose of the Study:

• To isolate and characterize a novel bacterial strain from Arctic soil.
• To determine the phylogenetic, physiological, and chemotaxonomic properties of the novel strain.
• To propose a new species within the genus Hymenobacter.

Main Methods:

• Isolation of bacteria from a till sample collected in Svalbard, Norway.
• Phylogenetic analysis using 16S rRNA gene sequences.
• Determination of cellular fatty acid composition, respiratory quinones, polar lipids, and DNA G+C content.
• Assessment of growth characteristics at different temperatures, pH, and salinity levels.

Main Results:

• A novel red-pink-pigmented, aerobic, Gram-stain-negative, rod-shaped bacterium, strain R2-4(T), was isolated.
• Phylogenetic analysis placed strain R2-4(T) within the genus Hymenobacter, with 16S rRNA gene sequence similarities to related species ranging from 94.51% to 96.05%.
• Chemotaxonomic analysis revealed specific fatty acid profiles (iso-C15:0, anteiso-C15:0, summed features 3 and 4, C16:1ω5c), MK-7 as the major quinone, and sym-homospermidine as the polyamine. The DNA G+C content was 61.6 mol%.

Conclusions:

• Strain R2-4(T) represents a novel species of the genus Hymenobacter.
• The proposed name for this new species is Hymenobacter arcticus sp. nov.
• This discovery contributes to the understanding of bacterial diversity in Arctic ecosystems.