论文总字数：20556字

摘 要

多环芳烃（polycyclic aromatic hydrocarbons, PAHs）具有致癌、致畸、致突变的三致效应。为研究微生物胞外聚合物(extracellular polymeric substances，EPS)对微生物降解污染物PAHs的效果和机制，本课题研究了两株菲和芘降解菌对多环芳烃的降解能力和动力学过程，分析了降解菌和EPS的酶活性及EPS组分。

原降解菌、胞外聚合物被提取的菌、EPS对污染物菲的降解能力大小为：原降解菌gt;胞外聚合物被提取的菌gt;EPS，EPS具有独立降解PAHs能力。降解菌中存在多种氧化还原酶，过氧化物酶酶活性大小顺序为：原降解菌gt;EPS被提取的降解菌gt;EPS, 在降解菲的过程中，原降解菌、胞外聚合物被提取的菌、EPS中的过氧化物酶活性稳定。脱氢酶的活性大小为原降解菌gt;胞外聚合物被提取的降解菌gt;EPS，EPS中并未检出脱氢酶。菲EPS中蛋白质、腐殖质、多糖的含量均高于芘EPS中的含量，菲和芘降解菌EPS中蛋白质含量最高，两种菌株对菲和芘降解效率不同可能因不同含量蛋白质、腐殖质、多糖对污染物的增溶和传质效率的差异所致。

关键词： 多环芳烃 胞外聚合物 过氧化物酶 蛋白质 降解

Enzymatic mechanism of extracellular polymeric substances promoting microbial degradation of polycyclic aromatic hydrocarbons

Abstract

Polycyclic aromatic hydrocarbons (PAHs) have carcinogenic, teratogenic and mutagenic effects. In order to study the effect and mechanism of microbial extracellular polymer substances (EPS) on microbial degradation of PAHs, the degradation ability and kinetics of PAHs by two strains of phenanthrene and pyrene-degrading bacteria were studied, and the enzymatic activities and EPS of the degrading bacteria and EPS were analyzed.

The degradation capacity of the original bacteria, the bacteria extracted from the extracellular polymer and EPS to phenanthrene was as follows: the original bacteria gt; the bacteria extracted from the extracellular polymer gt; EPS. EPS had the ability to degrade PAHs independently. There are many kinds of redox enzymes in degrading bacteria. The order of peroxidase activity is: original degrading bacteria gt; degrading bacteria extracted from EPS gt; EPS. During the process of degrading pollutants, the peroxidase activity in phenanthrene O, phenanthrene R and EPS is stable. The activity of dehydrogenase was the original degrading bacteria gt; the degrading bacteria extracted from extracellular polymer gt; EPS, and no dehydrogenase was detected in EPS. The content of protein, humus and polysaccharide in phenanthrene EPS is higher than that in pyrene EPS. The protein content of phenanthrene and pyrene degrading bacteria EPS is the highest. The difference of degradation efficiency of phenanthrene and pyrene between the two strains may be caused by the difference of solubilization and mass transfer efficiency of different protein, humus and polysaccharide contents to pollutants.

Key word: Polycyclic aromatic hydrocarbons extracellular polymeric substances

Peroxidase Protein degradation

目录

摘 要 I

Abstract II

目录 III

第一章 绪论 1

1.1引言 1

1.2多环芳烃的性质 1

1.3多环芳烃的污染现状和环境影响 2

1.4多环芳烃污染修复现状 3

1.4.1多环芳烃治理常用方法 3

1.4.2微生物降解多环芳烃的研究 3

1.4.3微生物修复PHAs污染土壤的技术手段 3

1.5微生物降解PAHs的酶学研究 4

1.6胞外聚合物的组成和性质 4

1.7胞外聚合物的提取和表征 4

1.7.1胞外聚合物的提取方法及优缺点 4

1.7.2胞外聚合物的表征 5

1.8胞外聚合物促进微生物降解PAHs机理研究进展 5

1.9研究目的及内容 6

第二章 材料与方法 7

2.1试剂与仪器 7

2.1.1主要试剂 7

2.1.2主要仪器 7

2.2实验方法 8

2.2.1本实验各类试剂配制方法 8

2.2.2降解菌的扩大培养 9

2.2.3微生物降解多环芳烃实验 9

2.2.4胞外聚合物的提取（阳离子交换树脂法） 9

2.2.5降解菌和胞外聚合物酶活性的测定 10

2.2.6胞外聚合物组成成分的测定 10

2.2.7菲降解动力学实验 10

2.2.8多环芳烃的HPLC测定 11

2.3数据处理方法 11

2.3.1多环芳烃残留浓度计算 11

2.3.2 EPS各组分含量计算 12

2.3.3酶活性计算 12

第三章 结果与讨论 14

3.1菌株的扩大培养 14

3.2降解菌对多环芳烃的直接降解 14

3.3原始菌和EPS被提取菌对PAHs的降解动力学 15

3.4 EPS对多环芳烃的直接降解 16

3.5降解菌和EPS的酶活性分析 17

3.5.1过氧化物酶分析 17

3.5.2脱氢酶分析 18

3.6胞外聚合物组成成分分析 19

第四章 总结与展望 22

4.1实验结论 22

4.2实验不足与展望 22

4.2.1实验不足 22

4.2.2实验展望 22

参考文献 23

版权说明 26

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