Tritonibacter horizontis gen. nov., sp. nov., a member of the Rhodobacteraceae, isolated from the Deepwater Horizon oil spill

A heterotrophic, Gram-stain-negative, aerobic, sodium-requiring and motile bacterium was isolated from oil-contaminated surface water of the Gulf of Mexico during the Deepwater Horizon oil spill. Strain O3.65 T showed highest 16S rRNA gene sequence similarity to Phaeobacter gallaeciensis BS107 T and Phaeobacter inhibens T5 T , both with 98.3 %, respectively. Based on complete genome analysis, highest similarity was observed to species of the genus Ruegeria. Strain O3.65 T exhibited a broad salinity, temperature and pH range of 0.5-10 % NaCl, 4-45 °C and 5.5-9.0, respectively. The DNA G+C content of strain O3.65 T was 61.5 mol%. The major respiratory lipoquinone was ubiquinone-10 (Q-10), the most dominant fatty acids (>1 %) comprised 18 : 1ω7c and 18 : 1ω7c 11-methyl, 10 : 0 3OH, 12 : 1 3OH, 14 : 1 3OH/3-oxo-14 : 0, 16 : 0, 16 : 0 2OH, 18 : 1 2OH and 12 : 1. The polar lipid pattern indicated presence of phosphatidylcholine, phosphatidylglycerol, an unidentified aminolipid, two unidentified phospholipids and seven unidentified lipids. On Difco marine broth agar, strain O3.65 T formed smooth, shiny white to beige and convex colonies with regular edges. Phylogenetic, phylogenomic and phenotypic differences revealed that strain O3.65 T represents a new species of a novel genus within the family Rhodobacteraceae, for which we propose the name Tritonibacter horizontis gen. nov., sp. nov. The type strain of the type species is O3.65 T (=DSM 101689 T =LMG 29740 T ).