Study on Isolation, Identification of A Petroleum Hydrocarbon Degrading Bacterium Bacillus fusiformis sp. and Influence of Environmental Factors on Degradation Efficiency

摘要

A hydrocarbon degrading bacterium KL2-13 was isolated from ten sites of oil contaminated soil in the Karamay oilfield. It was identified as the Bacillus fusiformis sp. bacterium based on its morphological and physiological characteristics and the 16S rDNA sequence analysis. The factors influencing the hydrocarbon degradation by the bacterium KL2-13 were determined. The test results have showed that the hydrocarbon degrading bacterium KL2-13 requires an optimum pH range of 6-8, and the optimum inoculation quantity is 3%. The low-concentration metal ions Fe2+, Mg2+ and Ca2+ can improve the degradation ability of the bacteria KL2-13.Atoo low concentration of Tween-80 does not show obvious promotion to the de- grading bacterium KL2-13, and an excessively high concentration can decrease the degradation ability of the bacterium, the best dosage of which is 2%. The hydrocarbon degrading rate reached 59.07%±0.37% under the optimum culture conditions.