Petrocella pelovolcani sp. nov., an Alkaliphilic Anaerobic Bacterium Isolated from Terrestrial Mud Volcano

Abstract

Diversity of extremophilic microorganisms in mud volcanoes is largely unexplored. Here we report the isolation of a novel alkaliphilic, mesophilic, fermentative bacterium (strain FN5suc^T) from a terrestrial mud volcano located at the Taman Peninsula, Russia. Cells of strain FN5suc^T are gram-stain-positive, non-sporeforming, motile rods. The temperature range for growth is 10–37°C, with an optimum at 30°C. The pH range for growth is 7.5–10.0, with an optimum at pH 9.0. The isolate utilizes various organic polymeric substances, organic acids, carbohydrates, and proteinaceous compounds. The end products of carbohydrates fermentation are acetate, CO₂ and trace amounts of H₂ and formate. The major cellular fatty acid compounds are C_16:0, C_{16:1 ω7c}, and monounsaturated dimethyl acetal C_14:1. Phylogenetic analysis reveals that strain FN5suc^T is most closely related to Petrocella atlantisensis = DSM 105309^T (98.4% 16S rRNA gene identity). The total size of the genome of strain FN5suc^T is 3.35 Mb, and a genomic DNA G+C content is 37.0 mol %. The genome contains complete glycolisis/glyconeogenesis pathway. We propose to assign strain FN5suc^T to the genus Petrocella, as a new species, Petrocella pelovolcani sp. nov. The type strain is FN5suc^T (=DSM 113898^T = UQM 41591^T).