sp. nov., a novel heterotrophic iron-reducing bacterium isolated from Mariana Trench sediment.

A novel chemoheterotrophic iron-reducing micro-organism, designated as strain LSZ-M11000, was isolated from sediment of the Marianas Trench. Phylogenetic analysis based on the 16S rRNA gene revealed that strain LSZ-M11000 belonged to genus , with 97 % identity to that of STGH, a mesophilic bacterium isolated from the Severo-Stavropolskoye underground gas storage facility in Russia. The polar lipid profile of strain LSZ-M11000 consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, as well as other unidentified phospholipids and lipids. The major fatty acids were C (28.4 %), C (15.8 %), iso-C (12.9 %), and anteiso-C (12.0 %). Strain LSZ-M11000 had no menaquinone. Genome sequencing revealed that the genome size of strain LSZ-M11000 was 2.97 Mb and the DNA G+C content was 37.9 mol%. The average nucleotide identity values between strain LSZ-M11000 and its close phylogenetic relatives, STGH and Z9, were 76.4 and 72.6 %, respectively. The corresponding DNA-DNA hybridization estimates were 20.9 and 23.4 %, respectively. Cells of strain LSZ-M11000 were rod-shaped (1.0-1.5×0.3-0.5 µm). Using pyruvate as an electron donor, it was capable of reducing KMnO, MnO, As(V), NaNO, NaNO, NaSO, NaSO, and KCrO. Based on phenotypic, genotypic, and phylogenetic evidence, strain LSZ-M11000 is proposed to be a novel strain of the genus , for which the name is proposed. The type strain is LSZ-M11000 (=CCAM 1008=JCM 39431).