Maritimibacter alkaliphilus gen. nov., sp. nov., a genome-sequenced marine bacterium of the Roseobacter clade in the order Rhodobacterales.

A Gram-negative, chemoheterotrophic, strictly aerobic, alkaliphilic, rod-shaped marine bacterium, designated HTCC2654(T), was isolated from the western Sargasso Sea by using a dilution-to-extinction culturing method. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain HTCC2654(T) belonged to the Roseobacter clade of the order Rhodobacterales. The 16S rRNA gene sequence similarity of the strain with respect to other members of the Roseobacter clade ranged from 90.4 to 95.1 %. In the phylogenetic analyses, the strain formed an independent phyletic line and could not be assigned to any other known genera of the Rhodobacterales. The DNA G+C content of strain HTCC2654(T) was 61.7 mol% by HPLC and 64.1 mol% from genome sequences. The predominant constituents of the cellular fatty acids were C(16 : 0) 2-OH (27.3 %), 11-methyl C(18 : 1) omega 7c (19.6 %) and C(18 : 1) omega 7c (17.3 %), and the major polar lipids were phosphatidylethanolamine, phosphatidylglycerol and phosphatidylcholine, which served to differentiate the strain from other members of the Roseobacter clade. On the basis of the taxonomic data obtained in this study, strain HTCC2654(T) represents a novel genus and species, for which the name Maritimibacter alkaliphilus gen. nov., sp. nov. is proposed. The type strain is HTCC2654(T) (=KCCM 42376(T)=NBRC 102057(T)).