The Effects Of Benzopyrene On Soil Microorganisms And The Research Of Degradation Condations Of Benzopyrene-Degrading Bacteria

With the human society developing, population increasing, and the scale of industrial production expanding, we use more energy and material.And the producing and living level is lowing, so much pollution is emitted.But we put much attention to how to improve our life, ignore the harm to humen's life.In respect of coke production, there are lots of waste gas,waste water and solid waste which contain lots of polycyclic aromatic hydrocarbons during producing. And polycyclic aromatic hydrocarbons is easily accumulating for its physical and chemical properties, and polycyclic aromatic hydrocarbons is an important pollutant for making cell mutating and inhibiting the growth of microorganisms. Benzopyrene is the most carcinogenic material among polycyclic aromatic hydrocarbons, that is why it is the target of this study .In this paper, the effects of important pollutions to the microorganisms were researched, high benzopyrene-degrading strains was screened and the degradation conditions were researched too. We deduce:(1)we use plate count agar (PCA) method to detect the effect of benzopyrene and other environmental pollutions on the number of microbes in soil, inhibitory effects of pyrene,lead,cadmium,phenanthrene and hexachlorocyclohexanes on bacteria in soil drop gradually. Inhibitory effects of benzopyrene on bacteria in soil is persistent than other pollutions.(2)In this paper,benzopyrene was used as sole carbon source to scre en de-grading strains,we get 18 benzopyrene-degrading strains.And we observe the strains' colonial morphology, cells' morphology and measure the gene sequences, the benzopyrene-degrading rate was me asured too.(3)4 high benzopyrene-degrading strains were choosen for phyiogeny, physiological and biochemical properties, growth curve and benzopy rene-degrading rate and how exogenous substances effect the benzop yrene-degrading rate was measured. The four strains were identified as Pseudomonas sp., Ochrobactrum sp.,Brevundimonas sp.,Pseudoxa nthomonas sp..Bioremediation of benzopyrene-contaminated oil was also experimentally studied. (4) Optimal conditions of growth for benzopyrene-degrading strain was researched under 5 factors and 4 levels by SPSS software. Optimal conditions of growth for SL-1 is beef extract,NH₄NO₃,pH8.5,200 r/min,25℃; for SL-2 is beef extract,peptone,pH7.5,200 r/min,15℃; for SL-4 is isomaltulose,(NH₄)₂SO₄,pH6.5,225 r/min,35℃; for SL-10 is beef extract,peptone,pH6.5,225 r/min,35℃. (5)The results of experiments for Bioremediation of benzopyrene-con -taminated soil show that the degradation rate of SL-1 is 76.3%, th -e degradation rate of SL-2 is 86.1%, the degradation rate of SL-4 is 85.7%, the degradation rate of SL-10 is 35.6%.