Alkalibaculum sporogenes sp. nov., isolated from a terrestrial mud volcano and emended description of the genus Alkalibaculum

A novel anaerobic, endospore-forming bacterium (strain M08 DMB T ) was isolated from a terrestrial mud volcano (Taman Peninsula, Russia). Cells of the strain were motile rods 1.3–2.0 µm long and 0.4 µm in diameter. The temperature range for growth was 5–42 °C, with an optimum at 30 °C. The pH range for growth was H 6.5–11.0, with an optimum at pH 8.0. Growth of strain M08 DMB T was observed at NaCl concentrations of 0–5.0 % (w/v) with an optimum at 1.0 %. Strain M08 DMB T utilized 3,4-dimethoxybenzoic acid, 2-methoxyphenol, carbon monoxide, glucose, fructose, mannose, xylose and yeast extract. The end product of glucose fermentation was acetate. The DNA G+C content of strain M08 DMB T was 32.3 mol% (obtained via whole genome sequencing). The closest phylogenetic relative of strain M08 DMB T was Alkalibaculum bacchi (family Eubacteriaceae , class Clostridia ) with 95.17 % 16S rRNA gene sequence similarity. Based on the phenotypic, genotypic and phylogenetic characteristics of the isolate, strain M08 DMB T is considered to represent a novel species of the genus Alkalibaculum , for which the name Alkalibaculum sporogenes sp. nov. is proposed. The type strain of Alkalibaculum sporogenes is M08 DMB T (=KCTC 15840 T =VKM B-3387 T ).