Hydrogenophaga electricum sp. nov., isolated from anodic biofilms of an acetate-fed microbial fuel cell

Abstract

A Gram-negative, non-spore-forming, rod-shaped bacterial strain, AR20T, was isolated from anodic biofilms of an acetate-fed microbial fuel cell in Japan and subjected to a polyphasic taxonomic study. Strain AR20T grew optimally at pH 7.0-8.0 and 25°C. It contained Q-8 as the predominant ubiquinone and C16:0, summed feature 3 (C16:1ω7c and/or iso-C15:02OH), and C18:1ω7c as the major fatty acids. The DNA G+C content was 67.1 mol%. A neighbor-joining phylogenetic tree revealed that strain AR20T clustered with three type strains of the genus Hydrogenophaga (H. flava, H. bisanensis and H. pseudoflava). Strain AR20T exhibited 16S rRNA gene sequence similarity values of 95.8-97.7% to the type strains of the genus Hydrogenophaga. On the basis of phenotypic, chemotaxonomic and phylogenetic data, strain AR20T is considered a novel species of the genus Hydrogenophaga, for which the name Hydrogenophaga electricum sp. nov. is proposed. The type strain is AR20T (= KCTC 32195T = NBRC 109341T).