Anaerotalea alkaliphila gen. nov., sp. nov., an alkaliphilic, anaerobic, fermentative bacterium isolated from a terrestrial mud volcano.

Diversity of extremophilic microorganisms in mud volcanoes is largely unexplored. Here, we report the isolation of a novel alkaliphilic, mesophilic, fermentative bacterium (strain F-3ap) from a terrestrial mud volcano located at the Taman peninsula, Russia. Cells of strain F-3ap are Gram-stain-positive non-motile rods. The formation of endospores is not observed. The temperature range for growth is 14-42 °C, with an optimum at 37 °C. The pH range for growth is 7.5-11.0, with an optimum at pH 9.0. The isolate utilizes various organic polymeric substances, organic acids, carbohydrates, and proteinaceous compounds. The end products of glucose fermentation are ethanol, CO, and H. The major cellular fatty acids of strain F-3ap are C, C, and C. Phylogenetic analysis reveals that strain F-3ap belongs to the order Clostridiales, with less than 91% of 16S rRNA gene sequence similarity to any species with a validly published name. The total size of the genome of strain F-3ap is 2.98 Mb, and a genomic DNA G + C content is 56.78 mol%. The whole-genome phylogenetic analysis confirms that strain F-3ap forms a distinct lineage within Clostridia. We propose to assign strain F-3ap to a new species of a novel genus Anaerotalea alkaliphila gen. nov., sp. nov. The type strain is F-3ap (= KCTC 15917 = VKM B-3406).