A nonphotosynthetic, Gram-stain-negative, rod-shaped and motile strain, designated Pet-1T, was isolated from oil-contaminated soil collected from Daqing oil field in China. Optimal growth occurred at 37 °C, pH 5.5 and in 1 % (w/v) NaCl. Q-10 was the sole respiratory quinone. The most abundant fatty acid was C18 : 1ɷ7c/C18 : 1ɷ6c (67.4 %). The major polar lipids were phosphatidylglycerol, aminolipid, phosphatidylethanolaine, phosphatidycholine, two unidentified lipids and two unidentified phospholipids. The genomic DNA G+C content was 69.3 mol%. Phylogenetic analysis based on 16S rRNA gene sequences revealed that Pet-1T shared the highest similarity (95.1 %) to Rhodobacter vinaykumarii DSM 18714T, followed by Sinorhodobacter populi sk2b1T (95.0 %) and Haematobacter massiliensis CCUG 47968T (95.0 %). In the phylogenetic tree, strain Pet-1T formed a separate branch from the closely related genera Rhodobacter, Pararhodobacter, Defluviimonas and Rhodovulum within the family Rhodobacteraceae. Based on the data from the current polyphasic study, it is proposed that the isolate is a novel species of a novel genus within the family Rhodobacteraceae, with the name Solirhodobacter olei gen. nov., sp. nov. The type strain of the type species is Pet-1T (=KCTC 72074T =CCTCC AB 2018368T).
Keywords: Rhodobacteraceae; Solirhodobacter; Solirhodobacter olei; nonphotosynthetic bacterium; oil-contaminated soil.