摘 要

Abstract II

1.1柴油的性质 1

1.1.1柴油的简介 1

1.1.2柴油的物理性质 1

1.1.3柴油污染的来源 1

1.2.柴油污染土壤概述 2

1.3.石油污染治理的方法 2

1.4.生物修复 2

1.4.1 降解柴油的微生物种类 2

1.4.2生物修复的作用机制 3

1.5.研究意义 4

第二章 实验方法与步骤 5

2.1实验材料与培养基 5

2.1.1实验材料与试剂 5

2.1.2实验仪器 7

2.2培养方法 7

2.2.1平板培养 7

2.2.2种子培养 7

2.2.3 摇瓶培养 7

2.3菌种的筛选与鉴定 8

2.3.1柴油降解菌的富集与驯化 8

2.3.2菌种的筛选 8

2.3.3菌种的分子学鉴定 8

2.4降解能力的测定 10

2.4.1.波长的选择 10

2.4.2 柴油标准曲线的绘制 10

2.4.3. 柴油降解率的测定 10

2.5生长曲线的测定 11

2.6降解影响因素的研究 11

第三章 结果与讨论 12

3.1 16S r DNA鉴定 12

3.2降解能力的测定 14

3.2.1最大吸收波长的确定 14

3.2.2标准曲线的绘制 14

3.2.3石油降解率的测定 15

3.3生长曲线的绘制 15

3.4降解影响因素的研究 16

3.4.1初始pH对生长量的影响 16

3.4.2菌种接种量对生长量的影响 17

3.4.3温度对生长量的影响 18

3.4.4柴油浓度对生长量的影响 19

3.5最佳条件下的降解率 20

第四章 结论与展望 22

4.1结论 22

4.2展望 22

参考文献 23

致谢 25

柴油降解菌的筛选及鉴定

摘要

柴油是许多机器设施的能源燃料，其组分基本属于有机物，一般不溶于水，所以污染问题很难处理干净。在各种处理措施中,生物修复法因其治理花费少,效率高,且不会带来二次污染等长处被认为是最有发展前景的修复石油烃类污染的方法。

本次研究思路是将0#柴油作为唯一碳源，从停车场的污染土壤中，筛出10株柴油降解菌。通过测定各个菌株的柴油降解率，来确定降解率效果最好的菌株。在这十株菌中降解率最高的菌3天内的柴油的降解率是70.2%。根据菌种的分子学鉴定操作和16S rDNA序列比对,对菌株进行了鉴定,将其鉴定并命名为Acinetobacter baumannii NCB9。

此外本课题还探究了菌株生长状况与初始pH值、接种量、培养温度、柴油浓度之间的关系。实验结果显示,当初始pH值为7.0、菌种的接种量为5%、培养温度为30℃、培养基中柴油浓度为1000mg/L时，该菌株的生长良好，并且降解率提高到了75%。

关键词：柴油降解菌；降解率；菌种鉴定；生长情况

Abstract

The composition of diesel oil is organic which with a lower density than water cannot be dissolved in water. Once it was leaked, it was hard to be removed thoroughly without leaving pollution. Among various kinds of treatment measures ,bioremediation method are thought to be the most promising method for removing of petroleum hydrocarbons pollution because of its governance cost less, high efficiency, will not bring secondary pollution and other advantages.  Nowadays, it has been developed to be the most popular method for dealing with diesel pollution.

In this dissertation, ten microbial bacterias with potential diesel oil degradation capacity and only carbon source of 0#Diesel oil was isolated from hydrocarbons polluted soil near the park, then screened out the strongest bacteria through searching the capacity of degradation by experiment. The bacteria with highest degradation in the ten bacterias had a degradation ratio of diesel oil as 70.2% in three days. Finally, through the experiment of bacteria molecular identification and the comparison of 16S rDNA sequence , the bacteria was identified and named by Acinetobacter baumannii NCB9.

Secondly,  four  factors  that  affect  the  bacteria  growth  and  the  degradation  ratio  todiesel  oil,  such  as  pH  value  of  the  culture  medium,  temperature,  inoculation  amount and  initial diesel oil concentration, were also studied in this paper.  The  result of the experiment  showed  that  the  optimum  culture condition  for Pseudomonas  sp. bacteria  were  pH5.0,  inoculation  by

5%,   incubation in 30℃ and an initial concentration of the diesel as 1000mg/L. The bacteria could grow vigorously with increasing the degradation ratio to 75% under the condition above.

Key words: diesel oil degradation bacteria; screening; degradation ratio;Identification of bacteria； growth

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