Pelovirga terrestris gen. nov., sp. nov., anaerobic, alkaliphilic, fumarate-, arsenate-, Fe(III)- and sulfur-reducing bacterium isolated from a terrestrial mud volcano.

A novel anaerobic, mesophilic, alkaliphilic, chemoorganotrophic bacterium (strain M08fum) was isolated from a salsa lake of a terrestrial mud volcano (Taman Peninsula, Russia). Cell of strain M08fum were Gram-stain-negative, rod-shaped, non-spore forming motile rods. The temperature range for growth was 10-45 °C (optimum at 30 °C). The pH range for growth was 7.0-11.0, with an optimum at pH 8.5-9.0. The isolate was capable of organic acids fermentation and anaerobic respiration with elemental sulfur, Fe(III) and arsenate. The end products of fumarate fermentation were succinate, acetate and CO. The closest phylogenetic relatives of strain M08fum were members of the family Geopsychrobacteraceae, class Desulfuromonadia. The genome of strain M08fum had a size of 3.10 Mb with a DNA G + C content of 53.1% (WGS). Genome analysis revealed the presence of genes involved in fumarate fermentation, arsenate reduction and resistance, sulfur respiration and Fe (III) reduction. Based on the phenotypic, genotypic and phylogenetic characteristics we propose to assign strain M08fum to a new species of a novel genus Pelovirga terrestris gen. nov., sp. nov. within the family Geopsychrobacteraceae. The type strain of Pelovirga terrestris is M08fum (=KCTC 15919 = VKM B-3407). This is the first representative of the class Desulfuromonadia, isolated in pure culture from a mud volcano and the first alkaliphile in the family Geopsychrobacteraceae.