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, AR20^T, was isolated from anodic biofilms of an acetate-fed microbial fuel cell in Japan and subjected to a polyphasic taxonomic study. Strain AR20^T grew optimally at pH 7.0−8.0 and 25°C. It contained Q-8 as the predominant ubiquinone and C_16:0, summed feature 3 (C_16:1ω7c and/or iso-C_15:02OH), and C_18:1ω7c as the major fatty acids. The DNA G+C content was 67.1 mol%. A neighbor-joining phylogenetic tree revealed that strain AR20^T clustered with three type strains of the genus Hydrogenophaga (H. flava, H. bisanensis and H. pseudoflava). Strain AR20^T 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 AR20^T is considered a novel species of the genus Hydrogenophaga, for which the name Hydrogenophaga electricum sp. nov. is proposed. The type strain is AR20^T (= KCTC 32195^T = NBRC 109341^T).