【作者】 刘君；

【导师】 赵吉； 孙建光；

【作者基本信息】 内蒙古大学 ， 环境科学， 2008， 硕士

【摘要】 随着人类社会的发展，人口不断增加，消费的能源和物质不断增加，且工业生产的规模不断扩大，且大部分地区生产生活水平落后，能源利用率低，这样在生产生活的过程产生了大量废物，而且由于当前大部分的目光主要集中在如何提高社会发展的水平，忽略了这些生活生产废物将会给人类的生产生活带来何种危害。以焦化生产为例，在生产过程中产生的废气、废水和固体废料中含有大量的多环芳香烃，而且由于多环芳香烃自身的物理化学性质，极易在环境中富集，且多环芳香烃会造成细胞突变、抑制微生物生长等危害，所以多环芳香烃已经成为环境中一个重要的污染物。而本文的研究对象之所以为苯并芘，是由于它的致癌性最强。本文研究了几种重要环境污染物对土壤微生物的影响，筛选出四株苯并芘高效降解菌，并对其降解特性进行了分析。主要结果如下：（1）采用微生物平板计数法研究了不同的环境污染物对土壤中微生物数量的影响，通过分析30d和60d的土壤微生物数量后，得出苯并芘对土壤微生物的抑制作用最持久。（2）以苯并芘为唯一碳源筛选出了18株降解菌，并且观察了降解菌的菌落形态、细胞形态、16S rDNA序列，并且测定了18株降解菌对苯并芘的降解率。（3）对四株降解能力较高的菌株进行了16S rDNA序列和系统发育学分析，生理生化实验，经菌落形态、细胞形态、16S rDNA测序，生理生化鉴定，分别鉴定为：SL-1属于假单胞菌属（Pseudomonas sp．），SL-2属于苍白杆菌属（Ochrobactrum sp．），SL-4属于短波单胞属（Brevundimonas sp．），SL-10属于假黄色单胞菌属（Pseudoxanthomonas sp．）。测定了以苯并芘为唯一碳源的降解菌的生长曲线、苯并芘降解率的变化曲线、外源物质对降解率的影响。（4）应用SPSS软件设计正交试验分析5因素4水平对降解菌的生长影响，选出降解菌最优培养条件：SL-1的最佳培养条件为牛肉膏、NH₄NO₃、pH8．5、转速200 r／min、温度25℃；SL-2的最佳培养条件为牛肉膏、蛋白胨、pH7．5、转速200 r／min、温度15℃；SL-4的最佳培养条件为麦芽糖、（NH₄）₂SO₄、pH6．5、转速225 r／min、温度35℃；SL-10的最佳培养条件为牛肉膏、蛋白胨、pH6．5、转速225 r／min、温度35℃。（5）土壤生物修复试验结果为：SL-1的降解率为：76．3％；SL-2的降解率为：86．1％；SL-4的降解率为：85．7％；SL-10的降解率为：35．6％；更多还原

【Abstract】 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%.更多还原