Brevirhabdus pacifica gen. nov., sp. nov., isolated from deep-sea sediment in a hydrothermal vent field.

A Gram-stain-negative, motile, aerobic bacterial strain, designated 22DY15T, was isolated from a deep-sea sediment sample collected from a hydrothermal vent field located in the East Pacific Rise. The isolate was a short rod with a single flagellum and was positive for catalase and oxidase activities. Q-10 was the predominant respiratory quinone. The major polar lipids consisted of phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, phosphoglycolipid, one aminolipid and three unidentified phospholipids. The principal fatty acid (>70 %) was C18 : 1ω7c. The genomic DNA G+C content was 64.3 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain 22DY15T represents a distinct lineage within the family Rhodobacteraceae. The closest relatives were species of the genera Aliiroseovarius (93.3–96.0 % 16S rRNA gene sequence similarity), Sulfitobacter (94.0–96.0 %) and Loktanella (92.0–95.9 %). Differential phenotypic properties, together with phylogenetic and genetic distinctiveness, revealed that strain 22DY15T could be differentiated from its most closely related genera. Therefore, it is proposed that strain 22DY15T represents a novel species in a new genus of the family Rhodobacteraceae, for which the name Brevirhabdus pacifica gen. nov., sp. nov. is proposed. The type strain of the type species is 22DY15T ( = JCM 19489T = DSM 27767T = CGMCC 1.12416T = MCCC 1K00276T).