Methyloceanibacter caenitepidi gen. nov., sp. nov., a facultatively methylotrophic bacterium isolated from marine sediments near a hydrothermal vent

A moderately thermophilic, methanol-oxidizing bacterium (strain Gela4^T) was isolated from methane-utilizing mixed-culture originating from marine sediment near a hydrothermal vent. Phylogenetic analysis of 16S rRNA gene sequences indicated that strain Gela4^T was closely related to members of the genus 'Methyloligella' (94.7 % similarity) within the class Alphaproteobacteria. Strain Gela4^T was a Gram-staining-negative and aerobic organism. Cells were rod-shaped and non-motile. The temperature range for growth of strain Gela4^T was 19-43 °C (optimal growth at 35 °C). Strain Gela4^T tolerated up to 9 % NaCl with an optimum at 1 %. The organism was a facultative methylotroph that could utilize methanol, methylamine, trimethylamine and a variety of multi-carbon compounds. The major cellular fatty acid and major respiratory quinone were C_{18: 1}ω7c and ubiquinone-10, respectively. The predominant phospholipids were phosphatidylcholine, phosphatidylglycerol and phosphatidylethanolamine. The DNA G+C content was 63.9 mol%. On the basis of the morphological, physiological, biochemical and genetic information, a novel genus and species, Methyloceanibacter caenitepidi is proposed, with Gela4^T (= NBRC 109540^T = DSM 27242^T) as the type strain.