Isolation and characterization of a novel phenanthrene (PHE) degrading strain Psuedomonas sp. USTB-RU from petroleum contaminated soil

The phenanthrene degrading novel bacterium strain USTB-RU was isolated from petroleum contaminated soil in Dagan oilfield, southeast of Tianjin, northeast China. The novel isolate was identified as Pseudomonas sp. USTB-RU on the basis of morphological, physicochemical characteristics and analysis of 16S rDNA gene sequence. The strain could degrade 86.65% of phenanthrene at an initial concentration of 100 mg L−1 in 8 days and identified intermediate metabolite evident the biodegradation of phenanthrene through protocatechuate metabolic pathway. The strain showed the potential to produce surface-active compounds that may have caused for the resulted efficient biodegradation through enhancing the substrate bioavailability. The results highlighted that the adaptability of USTB-RU to grow in a range of temperature, pH and potential to utilize various commonly co-exist pollutants in contaminated site other than phenanthrene as sole carbon and energy source. Further, susceptibility of the strain for the tested antibiotics inferred the possibility to absence of risk of spreading drug resistant factor to other indigenous bacteria. Therefore, the isolated novel strain USTB-RU may have a high potential for application in in situ bioremediation of phenanthrene contaminated environment.