Study On Petroleum Hydrocarbon Degrading Bacteria And Phosphorus-solubilzing Bacteria In Oil Pollutant

With oil pollution having a serious impact on humans and environment,the treatment of oil pollutant is always a great problem for the petroleum and petrochemical industry and even the society.Owning to biological treatment having advantages of safe,no secondary pollution and low cost,more and more research priorities on this problem focus on this method.Using bacteria with high efficiency to degrade oil has gradually become the research trends of oil pollution treatment,which tends to degrade various petroleum hydrocarbons with high degradation rate and can be applied stably.In the process of oil pollution treatment,nitrogen and phosphorus etc.were need to be added,which could promote bacteria on the degradation of petroleum hydrocarbons.Therefore,in order to increase the phosphorus content in the process of oil pollution treatment,phosphorus-solubilizing bacteria was isolated from coil pollutant promoting the degradation of petroleum hydrocarbons.In this study,petroleum hydrocarbon degrading bacteria with high efficiency to degrade oil and phosphorus-solubilizing bacteria were isolated from oil pollutant,providing superior strain resources for biological treatment of oil pollution.The main results were listed as follows:(1)Ten strains derading petroleum hydrocarbons were isolated from oil pollutant through enrichment culture,by 16S rRNA molecular biology identification,which were belonged to seven different generas.The ability analysis of crude oil degraded by the ten strains in 1%crude oil degradation medium for nine days showed that the strain of the UN-5 had the largest crude oil degradation rate(83.38%).(2)Ten phosphorus-solubilizing strains were isolated from oil pollutant by pikovskaya's agar,of which PSB-O-1 showed maximum solubilization ability(358.47 ?g/mL)in NBRIP liquid medium for one day.HPLC-analysis revealed that this strain secreted citric acid followed with pH reduction in the process of solubilizing phosphate,which demonstrated that the production of citric acid is one of phosphorus solubilization mechanisms.(3)By single-factor optimized experiments,the design of Plackett-Burman and Central Composite,the optimum values of solubilizing phosphorus condition for the strain PSB-O-1 were as follows:the concentration of glucose 15.58%(w/v),the temperature 30.82?,the concentration of Ca3(PO4)2 0.52%(w/v).On this condition,theoretical value of solubilizing amount is 572.023 ?g/mL.Through the verification experiment,relative error is only 2.65%compared with the theoretical prediction.(4)By mixture cultivation of phosphorus-solubilizing strain PSB-O-1 with petroleum hydrocarbon degrading strain UN-3 in modified crude oil degradation medium with Ca3(PO4)2 and 1%crude oil for seventeen days,the degradation rate was 16.41%higher compared with other processing,which demonstrated that the strain PSB-O-1 contributed to the strain UN-3 for the degradation of crude oil.