Efficient Degradation Of The Department Of Changqing Petroleum Pollutant Bacteria Screening And Its Features

With each year that goes by the oil are being applied more broadly, the oil pollutant left in the environment because of its nondegradable is to become a problem. The oil pollution dealed with by the microorganism is considered to be the most potential method, which is valid and safe. It is very important to screen the high hydrocarbon degradation strains or combined bacterial consortium that have high enzyme activity.Four high-effective crude oil-degrading bacteria strains were isolated from oil contaminated soil and water of Chang-Qing and Yan-Chang Oil Field.PSA, PDA2, PDB3and PEA1, which were identified to be Rhodococcs sp., Pseudomonas sp., Pseudomonas aeruginosa and Pseudomonas sp. Degradation of different hydrocarbon and enzymes in hydrocarbon degradation by the strains or combined bacterial consortium were studied, as well as the biodegradation conditions and characteristics.The results were as follows:(1) The four strains could degrade crude oil, heavy oil, naphthalene and hexadecane.The degradation rate of1%crude oil was66.3%by PDB3, the rate of1%hexadecane was93.2%by PSA, the rate of1%heavy oil was39%by PDA2and the rate of0.2%naphthalene was100%. The crude oil degradation rate was76.2%by combined bacterial consortium of PDB3and PEA1, all of these were at a high level in the similar research, More specifically,The change of Changqing oil total hydrocarbon GC spectrum showed that straight-chain paraffin below the40C almost were degradation.(2) The Changing oil degradation rate in the MSM plate medium containing oil is higher than that in the MSM medium containing oil, it showed that the biodegradation is more suitable for the the soil by the four strains.(3) The influence factors on the changqing oil degradation by the four strains were studied, the strain PDB3had the best biodegradation under30℃, pH7,2%crude oil,5%inoculum size,600mg/mL H2O2N:P=1:1,while the best degradation condtions of combined bacterial consortium PDB3+PEA were as the same as PDB3.(4) The four strains have certain salt and temperature resistance,the Changqing oil degradation rates by the strains were above40%under45℃and1%～3%salinity. (5) Biosurfactants, acid and gas secreted by the four strains, the contents were different according with the charactericstics of hydrocatbons. Surfactants secreted by the strains doesn’t mean secreting a lot of emulsifier, Changqing oil degradation by the four strains mainly depended on the surfactant and the shaking table, which made the crude oil and water fused togther with emulsing droplet. Biosurfactant help the hydrocarbon degradation cooperated with emulsifier.(6) Changqing oil degradations by the four strains need lipase, TTC dehydrogenase and dioxygenase, it coude improve the degradation rate when adding the three enzymes, which coule apply to the actual environment.