Shewanella dovemarinesis sp. nov., a psychrotolerant bacterium isolated from Mid-Atlantic Ridge deep-sea sediments

Strains MAR441T and MAR445 were isolated from Mid-Atlantic Ridge (MAR) sediments with a depth of 2,734 m, and found to be member of the genus Shewanella. The strains were rod shaped, pigmented, non-motile, and capable of anaerobic growth either by fermentation of carbohydrates or by anaerobic respiration. The strains utilized a variety of electron acceptors, including nitrate and ferric compounds and could utilize peptone when grown anaerobically in a two-chambered microbial fuel cell (MFC), which use carbon cloth electrodes and deliver a stable power output of ~150-200 mW/m2. The major fatty acids were typical of the genus Shewanella, with major components of C13:0, iso-C13:0, iso-C15:0, C16:0, C16:1ω7c, C18:1ω7c and C20:5ω3 fatty acids. The DNA G+C content of strains MAR441T and MAR445 were 42.4 mol %. 16S rRNA gene sequence analysis indicated that strains MAR441T and MAR445 were most closely related to Shewanella olleyana (sequence similarities 97.9 %). DNA-DNA hybridization demonstrated only 15.6-37.2 % relatedness between strain MAR441T and the type strains of related Shewanella species. Phenotypic characteristics confirmed that these isolates constituted a novel species of the genus Shewanella. The type strain of Shewanella dovemarinensis is MAR441T (=ATCC BAA-2408 T =DSM24955 T).