Fontibacter ferrireducens sp nov., an Fe(III)-reducing bacterium isolated from a microbial fuel cell

A novel, dissimilatory Fe(III)-reducing bacterium, designated strain SgZ-2(T), which could couple glucose oxidation to iron reduction for energy conservation, was isolated from a microbial fuel cell. The isolate was Gram-staining-negative, catalase-positive, oxidase-negative and facultatively anaerobic. The strain was able to grow on tryptic soy agar at 15-37 degrees C and in the presence of 0-5% (w/v) NaCl. The predominant cellular fatty acids (>5 %) were iso-C-15:0, iso-C-17:0 3-OH and iso-C-17:1 omega 9c; the major respiratory quinone was MK-7; the major polar lipids were phosphatidylethanolamine, an unidentified aminolipid and three other unidentified lipids; and the DNA G + C content was 55.3 mol%. Phylogenetic analyses based on 16S rRNA sequences showed that the novel strain was most closely related to Fontibacter flavus CC-G ZM-130(T) (99.9 % sequence similarity), and was a member of the family Cyclobacteriaceae. The levels of DNA DNA relatedness observed between strain SgZ-2(T) and F. flavus CCM 7650(T) (<41 %) indicated that the two strains represented two distinct species. Based on phylogenetic analyses and phenotypic characteristics, strain SgZ-2(T) represents a novel species of the genus Fontibacter, for which the name Fontibacter ferrireducens sp. nov. is proposed. The type strain is SgZ-2T (=CCTCC M 2011498(T) = KACC 16525(T)).