Isolation and Study of Indigenous Bacteria of the Contaminated Soils in Southern of Tehran Oil Refinery plant for Bioremediation of Oil ontaminations

Increasing growth of population and consequent development of industries and refinery plants cause high amounts of hydrocarbon pollutants enter to environment. Bioremediation or biological removal of petroleum hydrocarbons from soil or water is more efficient than the other physical and chemical remediation technologies. Indigenous bacteria are important because of their long term exposure and compatibility to hydrocarbon contaminants. Therefore, the aim of this study was isolation and comparison of oil consuming bacteria efficiency in the oil contaminated soils in southern of Tehran oil refinery plant. Six samples from the contaminated soil were collected and then the superior oil degrading bacteria were isolated through three laboratory steps: i) Isolation and purification of indigenous oil degrading bacteria in a soil extract agar as a selective media, ii) The study of efficiency of the isolates in a liquid mineral based media with 7% (V/V) of gas oil. iii) The comparison of the respiration rates of the isolates in a media containing 3% (W/W) gas oil. At the end of three steps, among all the oil degrading isolates, two isolates of BJ.1 and BM.1 with respiration rates of 2.1 and 1.8 mg CO2 per gram sand-perlite per month, were ultimately selected as the most powerful and efficient isolates for oil degradation, respectively.