Limnobacter olei sp. nov., a Novel Diesel-Degrading Bacterium Isolated from Oil-Contaminated Soil

A bacterial strain P1 T , capable of degrading diesel and converting thiosulfate to sulfate was isolated from an oil-contaminated soil sample. The cells were Gram-stain-negative, slightly curved rods and motile with a single polar flagellum. Growth of the strain was observed at 4–45 °C (optimum at 28 °C), at pH 4.0–12.0 (optimum at pH 10.0) and with 0–15.0% (w/v) NaCl (optimum at 2.0%). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain P1 T was closely related to the members of the genus Limnobacter , with the highest sequence similarity to Limnobacter thiooxidans DSM 13612 T (99.8%), followed by Limnobacter alexandrii LZ-4 T (99.4%), Limnobacter parvus YS8-69 T (98.8%), Limnobacter litoralis KP1-19 T (97.6%), and Limnobacter humi UCM-39 T (97.5%). The draft genome sequence of strain P1 T was 3.40 Mb long, with a DNA G + C content of 52.4%. The average nucleotide identity and digital DNA-DNA hybridization values between strain P1 T and the closely related type strains were in the range of 71.8–85.1% and 18.1–28.7%, respectively. The predominant cellular fatty acids of strain P1 T included C 16: 0 , summed feature 3 (C 16: 1 ɷ 7 c and/or C 16: 1 ɷ 6 c ), summed feature 8 (C 18: 1 ɷ 7 c and/or C 18: 1 ɷ 6 c ), and summed feature 7 (C 19: 1 ɷ 6 c and/or C 19: 1 ɷ 7 c and/or C 19: 1 cyclo). In addition, the main polar lipid was composed of diphosphatidylglycerol, phosphatidylethanolamine, and phosphatidylglycerol. Q-8 was the sole respiratory quinone. Based on the polyphasic characterization, strain P1 T (= KCTC 72814 T = CCTCC AB 2019403 T ) represents a novel species of the genus Limnobacter , for which the name Limnobacter olei sp. nov. is proposed.