Hydrogenophaga aquatica sp. nov., isolated from a hot spring

Area of Science:

• Microbiology
• Bacteriology
• Taxonomy

Background:

• Hot springs harbor diverse microbial communities.
• The genus Hydrogenophaga comprises aerobic, Gram-negative bacteria with various metabolic capabilities.

Purpose of the Study:

• To characterize and classify a novel bacterial isolate (strain CC-KL-3^T) from a hot spring environment.
• To determine the phylogenetic and chemotaxonomic relationships of strain CC-KL-3^T within the genus Hydrogenophaga.

Main Methods:

• Polyphasic taxonomic characterization including 16S rRNA gene sequencing and DNA-DNA hybridization.
• Phenotypic analyses of growth conditions (temperature, pH, salinity) and chemotaxonomic profiling (fatty acids, quinones, polyamines).

Main Results:

• Strain CC-KL-3^T showed high 16S rRNA gene similarity to Hydrogenophaga bisanensis and Hydrogenophaga atypica, but low DNA-DNA relatedness (<20%).
• The isolate exhibited distinct phenotypic traits, including a temperature range of 15-42°C and optimal growth at pH 7.0 and 0% NaCl.
• Chemotaxonomic analyses revealed specific fatty acid profiles (C16:0, C16:1ω7c/C16:1ω6c, C18:1ω7c/C18:1ω6c) and ubiquinone (Q-8) as the major quinone.

Conclusions:

• Strain CC-KL-3^T represents a novel species within the genus Hydrogenophaga, family Comamonadaceae.
• The proposed name for this new species is Hydrogenophaga aquatica sp. nov., with strain CC-KL-3^T as the type strain.