Identification and characterization of a novel hydrocarbon-degrading Marinobacter sp. PY97S

Abstract:

Abstracts: [Objective] To identify and characterize a hydrocarbon-degrading bacterium isolated from the sediment of the Yellow Sea. [Methods] We used 16S rRNA gene sequences based phylogenetic analysis, physiological and biochemical characterization, DNA G+C content assaying, determination of cellular fatty acids, testing of carbon sources and respiratory lipoquinone and experiment of DNA–DNA relatedness. Its capability of degrading aliphatic hydrocarbons in ONR7a media supplemented with nine n-alkanes, separately, as sole source of carbon and energy was further determined. [Results] The Gram-negative isolate PY97S was a member of the genus Marinobacter, catalase- and oxidase-positive, and with Q-9 as its predominant respiratory lipoquinone. The similarity between its 16S rRNA gene and that of its most closely related type strain in GenBank Marinobacter koreensis DD-M3T was 96.93%, and their level of DNA relatedness was 46.7%. The appropriate temperature for its growth ranged from 15℃ to 35℃ with the optimum of 30℃, the appropriate initial acidity from pH 6.0 to 9.5 with the optimum of pH 7.0, and the appropriate salinity (NaCl) from 0% to 10% with the optimum of 0%. It metabolized many carbohydrates and organic acids and was sensitive to diverse antibiotics including ampicillin and piperacillin. The G+C content of its genomic DNA was 48.2 mol%. The major fatty acids were 2-methyl C15:0 (29.97%), C16:1ω7c (27.22%), C12:0 (22.22%) and C16:1ω9c (5.73%). [Conclusion] The isolate PY97S was identified as a petroleum hydrocarbon-degrading novel species of genus Marinobacter, holding the potential of being applied in the bioremediation of oil spill.

Key words:Keywords: petroleum hydrocarbons, PAHs, alkane, biodegradation, taxonomic identification