Study On Isolation,characterization And Application Of Highly Efficient Petroleum Degradation Microorganism

High global demand for oil products has led to an increase in oil extraction and processing.With the development of petrochemical industry,the crude oil pollution problem is increasingly serious.Bioremediation is a new and efficient technology.Compared with traditional physical or chemical remediation,bioremediation is more economical,more efficient and more environmentally friendly.Comparative study on the petroleum crude oil degradation potential of microbes from petroleum contaminated soil and non-contaminated soil was performed in the present paper.The potential petroleum degrading bacteria form three soil samples were screened,identified and tested.The effects of five environmental factors(temperature,p H value,salinity,nitrogen and phosphorus sources)and four degradation conditions(inoculation amount,soil water content,organic waste residue and surfactant addition)on the growth of microorganisms and petroleum degrading rate were discussed.According to the results of the optimization,the laboratory simulation experiment was carried out to study the application effect of microbial agents.The results are as follows:(1)Nine highly efficient petroleum degrading bacteria and three highly efficient petroleum degrading fungi were screened from petroleum contaminated soil.Among them,bacterial strain A5,A14 and fungal strain AF1 had the highest oil degradation rates,46.55%,39.22% and 46.17% respectively.Four highly efficient petroleum degrading bacteria and one highly efficient petroleum degrading fungus were screened from non polluted soil.The degradation rates of G1,G6 and GF were 46.17%,41.51% and 52.12%,respectively.The results show that there are also microorganisms with petroleum degradation potential in non petroleum polluted environment.(2)In the laboratory simulation experiment of microbial remediation,it was found that for 1% oil contaminated soil,the bacteria with the best degradation efficiency was A5,which had 67.09% of the oil degradation rate,and the fungus with the best degradation efficiency was GF,which had 66.32% of the oil degradation rate.The degradation rates of bacteria and fungi were 71% and 73.17%,respectively.Compared with single bacteria treatment,microbial combination was more effective in the degradation of oil in soil.(3)In the experiment of different oil polluted soil remediation,the activity of microorganism decreased with the increase of biodegradation rate.In addition,organic waste plays an important role in the process of microbial proliferation and accelerated degradation of petroleum.The addition of organic waste will significantly improve the efficiency of microbial degradation of petroleum,and the most significant improvement for the efficiency of bacterial fungal combination degradation,can be increased by 25%.