Isolation, Identification And Degradation Characteristics Of Petroleum-Degrading Bacteria

With the development of modern petroleum industry, it brings great economic benefits, at the same time it poses serious threat to the environment. During the process of reconnaissance, exploitation, transportation and deposit, a large area around the oil field suffered from serious pollution. The present disposal ways of oil pollution includes physical technique, chemical technique and biological restoration, among which, biological restoration has distinct advantages because the microbiolgical technique attracts peoples' attention due to its economy high efficiency and no second contamination.Laboratory scale batch studies were performed to test the petroleum hydrocarbon biodegradation ability of two Pseudomonas. strains B1 and B2 isolated from TPH(Total Petroleum Hydrocarbon composed of alkane, aromatics, nitrogen-, sulfur-, and oxygen-containing compound, and asphaltene fraction of crude oil) contaminated soil in the vicinity of an coking plant in Tianjin. Strains Bl and B2 could utilize TPH as the sole source of carbon and energy. The whole bioremediation processes are significantly affected by the inherent capabilities of the microbe, their ability to overcome the bioavailability limitations in environment, and environmental factors such as oxygen concentration, temperature, pH, salinity, extent of petroleum dispersion, nutrients and electron acceptor availability. In our research, The maximum degradation nearly 80% was showed at temperature of 35℃, pH of 7.0, N:P ratio of 5:1 and initial TPH content of 2000mg/kg respectively. On the basis of test and analysis the potted plant experiment of maize and rice, and add in the petroleum hydrocarbon-degrading bacterial we isolated from the petroleum hydrocarbon-contaminated soil, we studied the growth of the plant root influenced by the petroleum hydrocarbon and those contaminations degraded by the plant-microbe system. The results showed that, the growth of the root was accelerated when the petroleum hydrocarbon content was lower than 1000mg/kg. Rice can degrade the petroleum hydrocarbon too(26.2% in three weeks) and its resistance to the petroleum hydrocarbon was stronger than maize. The degradation of the petroleum hydrocarbon by rice, microbe and rice-microbe system was obviously different and the rice-microbe system was the best (53.3%).