Isolation and identification of a hydrocarbon-degrading bacterium Gordonia sp. S14-10 from the surface water of Atlantic Ocean and analysis on its related characteristics

Abstract:

Abstract: [Objective] The aim of this study is to isolate novel and efficient hydrocarbon-degrading bacteria (HDBs) from pelagic ocean. [Methods] The surface water sample from Atlantic Ocean was enriched in NH medium with crude oil: diesel oil (in a ratio of 1:1) as the sole carbon source. HDBs were isolated and their degradation ability was tested in MMC medium, and further subjected to genotypic and phenotypic analysis. Polymerase chain reaction with degenerate primers was performed to detect the genes encoding integral-membrane non-heme iron monooxygenase (AlkB) and cytochrome P450 CYP153 family. Meanwhile, the production of biosurfactant was examined by surface tension measurement, then extracted and purified for component characterization. [Results] A hydrocarbon-degrading bacterium named S14-10 was obtained, which can utilize C10?C36 as the sole carbon source. Analysis of 16S rRNA sequence showed that it belonged to Gordonia genus showing the highest similarity (99.86%) with type strain of Gordonia terraeT, while secA1 sequence showed a low identity only 93.69%. Furthermore, two genes alkB and CYP153 P450 were obtained with PCR, which had highest similarities 88.76％and 99.61％ to that of Gordonia sp. TF6, respectively. In addition, strain S14-10 was found to produce glycolipid biosurfactant, which lowered the surface tension of water to 31.6 mN/m. [Conclusion] Strain S14-10 is possibly a novel species of Gordonia, and the first hydrocarbon-degrading bacterium isolated from open sea. It has potential in bioremediation of oil contaminated environment.