Hydrogenophaga temperata sp. nov., a betaproteobacterium isolated from compost in Korea

A Gram-negative, rod-shaped, non-spore-forming and motile bacterial strain TR7-01(T) was isolated from a compost soil in South Korea and subjected to a polyphasic taxonomic study. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain TR7-01(T) belonged to the genus Hydrogenophaga within the class Betaproteobacteria. Strain TR7-01(T) exhibited 16S rRNA gene sequence similarity values of 95.0-98.3% to members of the genus Hydrogenophaga: Hydrogenophaga bisanensis DSM12412(T) (98.3%), Hydrogenophaga flava DSM 619(T) (97.1%), Hydrogenophaga pseudoflava ATCC 33668(T) (96.8%), Hydrogenophaga intermedia S1(T) (96.4%), Hydrogenophaga atypica BSB 41.8(T) (95.8%), Hydrogenophaga defluvii BSB 9.5(T) (95.7%), Hydrogenophaga palleronii CCUG 20334(T) (95.6%), Hydrogenophaga caeni EMB71(T) (95.4%) and Hydrogenophaga taeniospiralis ATCC 49743(T) (95.0%). Chemotaxonomic data revealed that strain TR7-01(T) possesses ubiquinone Q-8, the G+C content was 69.9 mol%, and the predominant fatty acids were 16 : 1 ω7c/15 : 0 iso 2OH, 18 : 1 ω7c/ω9t/ω12t and C(16:0), all of which corroborated our assignment of the strain to the genus Hydrogenophaga. The results of DNA-DNA hybridization and physiological and biochemical tests clearly demonstrated that strain TR7-01(T) represents a distinct species. Based on these data, TR7-01(T) (= KCTC 12203(T) = DSM 18117(T)) should be classified as a novel Hydrogenophaga species, for which the name Hydrogenophaga temperata sp. nov. has been proposed.