A Gram-stain-negative, strictly aerobic, short-rod-shaped bacterium, motile by a single polar flagellum, designated OUC007T, was isolated from seawater at a depth of 1000 m in the Mariana Trench. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain OUC007T formed a lineage within the family Salinisphaeraceae that was distinct from the most closely related genera Oceanococcus and Salinisphaera, with 16S rRNA gene sequences similarities ranging from 89.3 to 90.8 %, respectively. Strain OUC007T grew with 0-7 % (w/v) NaCl (optimum, 2-3 %), at 10-45 °C (37 °C) and at pH 7.0-9.0 (7.0-8.0). The major respiratory quinone was ubiquinone-8 (Q-8). The polar lipids of strain OUC007T comprised one phosphatidylethanolamine and three unidentified polar lipids. The predominant fatty acid (more than 10 % of total fatty acids) was summed feature 8 (C18 : 1ω7c or/and C18 : 1ω6c). The DNA G+C content of strain OUC007T was 63.1 mol%. On the basis of polyphasic taxonomic analysis, the strain OUC007T is considered to represent a novel species in a new genus of the family Salinisphaeraceae, for which the name Abyssibacter profundi gen. nov., sp. nov. is proposed. The type strain is OUC007T (=KCTC 52933T=MCCC 1K03450T).
Keywords: Abyssibacter profundi; Mariana Trench; seawater.