Thalassolituus alkanivorans sp. nov., a hydrocarbon-utilizing bacterium isolated from the Mariana Trench

Two strains, TMPB967^T and TTPB476, were isolated from two different locations in the Mariana Trench. Cells of strains TMPB967^T and TTPB476 were Gram-negative, curved rod-shaped (0.35-0.6 µm×2-4 µm) with flagella. Both strains were catalase- and oxidase-positive. Strains TMPB967^T and TTPB476 could grow at 4-37 °C (optimum, 37 °C), at pH 6-9 (optimum, pH 6-7) and in the presence of 0-8 % (w/v) NaCl (optimum, 5 %). Both strains could grow with tetradecane or hexadecane as the sole carbon source. The predominant isoprenoid quinone was ubiquinone 9. The major cellular fatty acids of strains TMPB967^T and TTPB476 were C_18 : 1  ω9c, C_16 : 0 and summed feature 3 (C_16 : 1  ω7c or ω6c). The polar lipid profile included phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and an unknown aminolipid. The DNA G+C contents of strains TMPB967^T and TTPB476 were 53.1 and 53.0 mol%, respectively. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the most closely related validly published species were Thalassolituus marinus IMCC1826^T (97.1 % similarity) and Thalassolituus oleivorans MIL-1^T (95.9 % similarity). Digital DNA-DNA hybridization results of strain TMPB967^T with TTPB476, T. marinus IMCC1826^T and T. oleivorans MIL-1^T were 99.9, 20.9 and 20.2 %, respectively. Average nucleotide identity results of strain TMPB967^T with TTPB476, T. marinus IMCC1826^T and T. oleivorans MIL-1^T were 100, 75.8 and 72.0 %, respectively. On the basis of the phenotypic, chemotaxonomic and molecular features, strains TMPB967^T and TTPB476 belong to a novel species within the genus Thalassolituus, for which the name Thalassolituus alkanivorans sp. nov. is proposed. The type strain is TMPB967^T (=KCTC 82621^T=MCCC 1K05476^T).