Isolation, Identification And Application Research Of Hydrocarbon-degrading Microorganism

In the whole world, petroleum pollution is one of the biggest environmentalproblems. Bioremediation is known as the most efficient technique with theadvantages of high efficiency, economic, prevent of second pollution and wideapplication compared with other chemical and physical treatments. Therefore, theresearch on bioremediation of the petroleum hydrocarbon has considerable practicalconsequence.A hydrocarbon-degrading strain ZRS was isolated from petroleum-contaminatedsoils sampled from Xinjiang oil field. The strain ZRS was identified as Acinetobactersp. by polyphasic taxonomy including the phenotype, physic-chemical properties,carbon source and16S rDNA sequence, named Acinetobacter beijerinckii ZRS.The optimum conditions of strain growth were confirmed by adapting singlefactor experiments, and the effects of environmental factor to hydrocarbondegradation were analyzed. Substrates utilizing of medium and conditions, and thedegradation potential of hydrocarbon by the strain was exerted extensively.The nutrition appending to the artificial seawater was optimized by adaptingResponse Surface Methodology (RSM). RSM was beneficial for this strain to degradediesel oil better. The optimal nutrition concentrations appending to the artificial seawaterwere as follows:2.05g/L(NH4)2SO4,1.46g/L Na2HPO4,14.07mg/L yeast extract. Thedegradation rate of the diesel oil in artificial seawater was increasing from20.87%to80.40%in7days, which was in accordance with the prediction acquired from the RSMresults.The hydrophobicity of strain ZRS was studied to discuss the mechanism of strainsconsuming diesel oil. RSM and single factor experiments wre implemented to optimizethe culture medium to enhance bioemulsifier production. Then, the chemicalcomposition of the bioemulsifier produced by the strain ZRS were studied. So did thephysic-chemical properties. The results indicated that this bioemulsifier which couldprominently emulsify diesel oil, was consisted of proteins. The bioemulsifier retained itsproperties at a wide range of pH values, high temperatures and high salinities (up to5%[w v] Na+and24%Ca2+). Therefore, this bioemulsifier showed strong potential tobe used for bioremediation of oil pollution.