Roseitranquillus sediminis gen. nov., sp. nov. a novel genus and species of the family Rhodobacteraceae, isolated from sediment of an Arctic fjord.

A Gram-negative, aerobic, non-motile, oxidase-positive, catalase-positive, rod-shaped bacterium, designated strain MCCB 386T was isolated from sediment samples collected from Kongsfjorden, an Arctic fjord. The strain MCCB 386T showed growth at 4-37 °C (optimum 27°C) in the presence of 1-8% NaCl (w/v, optimum 3.5%) and at pH 6.0-8.0 (optimum pH 7.0). The major fatty acids were C18:1ω7c (54.0%) and 11-methyl C18:1ω7c (22.6%). The dominant respiratory quinone was Q-10. The major polar lipids comprised of phosphatidylcholine (PC), diphosphatidylglycerol (DPG), phosphatidylglycerol (PG), phosphoglycolipid (PGL), one unidentified aminolipid, two glycolipids and two unidentified lipids. The genomic G+C content of the strain MCCB 386T was 68.1 mol%. The 16 S rRNA gene sequences based phylogenetic analysis of MCCB 386T showed that Psychromarinibacter halotolerans YBW34T (95.88%) is the most closely related species. In addition, overall genome relatedness indices (OGRI) of MCCB 386T with closely related strains were lower than threshold level for species and genus delineation. The analysis of Biosynthetic Gene clusters (BGCs) revealed the potential of this strain for production of novel bioactive secondary metabolites. As per polyphasic taxonomic characterisation, strain MCCB 386T represents a novel species of a novel genus for which the name Roseitranquillus sediminis gen. nov., sp. nov. is suggested. The type strain of the species is MCCB 386T (= JCM 33,538T= KACC 21,531T).