铅锌污染对土壤细菌群落结构的影响及优势细菌吸附性能的研究

东北农业大学

硕士学位论文

铅锌污染对土壤细菌群落结构的影响及优势细菌吸附性能的研

究

姓名：任广明

申请学位级别：硕士

专业：应用微生物学

指导教师：曲娟娟

20090620

摘要

含重金属铅不仅影响了农产品的产量与品质

并通过食物链危害动物和人类的生命健康土壤重金属铅研究重金属污染条件下土壤微生物的群落结构多样性能揭示微生物对重金属污染环境的适应为环境治理提供理论依据简称PCR-DGGE技术

能较好地克服传统微生物培养方法的局限性

结合克隆和序列分析

本文采集了黑龙江省一铅锌矿区附近受不同程度铅总铅浓度范围为616.67-3353.33 mg/L总铅

根据培养细菌计数锌污染对土壤微生物数量有明显的抑制用通用引物对其中的16S rDNA进行扩增

Denaturing Gradient Gel Electrophoresis根据电泳图谱分析长期受铅

不同铅

可见铅不同程度的铅还使群落结构以及优势种群发生了改变

得到矿区土壤中的优势细菌的分子信息

从重金属铅锌污染矿区土壤中分离筛选出10株抗性细菌

确认2株细菌为指纹图谱指示的优势菌株Bacillus pumilus Pseudomonas aeruginosa

本文分别命名为M1和M2锌抗性能力均已达到4000 mg/L

投菌量为20 g/L25min时在Zn2+浓度为50 mg/L pH5.0吸附率最高为68.61%投菌量为30 g/L15min时在Zn2+浓度为50 mg/L pH5.0

吸附率最高为76.82%

铅微生物修复短小芽孢杆菌

Pseudomonas aeruginosa生物吸附

Effect of lead and zinc contamination on microbial community diversity in soil and research on

bioadsorption of advantage bacteria

Abstract

The pollutants containing heavy metals lead and zinc entered the soil in variety ways. They not only affected the yield and quality of agricultural products, but also polluted the air and water quality of the environment, and through the food chain, endangering the lives of animal and human health. In recent years, heavy metals lead and zinc contaminated in the soil has become a hot spot research.

Research on the effect of long-term exposure to heavy metals on structure and microbial community diversity in soils could reveal the tolerance and adaptation of microbes, and supply useful information for environment monitoring. Denaturing gradient gel electrophoresis(DGGE)is one kind of molecular biology methods for detecting mutation of DNA. Since traditional methods of cultivating require the use of media or substrates on which only 1.0-10% of soil microorganisms can grow, applications of DGGE technique has been applied to soil ecosystem in recent years and has enabled the researchers to study microbial diversity at the molecular level.

In this paper, Seven soil samples were collected from seven different sites near a lead and zinc mine in Heilongjiang province. The contents of total lead were 616.67-3353.33 mg/L, and the contents of zinc were 676.67-1055.0 mg/L. The microbial speciation in lead and zinc contaminated soil at different sites was studied. Bacterium were found being influenced negatively by lead and zinc.

Amplified 16S rDNA sequences obtained from community DNA by denaturing gradient gel electrophoresis (DGGE). Fingerprint reflected the altered community diversity with the lead and zinc gradient as expressed in terms of the position and number of bands. Based on the profiles of DGGE, bacterial populations were changed in all of the soil-sampling sites. That observation may indicate that the exist of lead and zinc resistant species. Quantity and structure varied in bacterial richness among the low contaminated sites, but with no sharp difference. The observed changes in the different soil microbial populations probably resulted from the combined direct and indirect effects of lead and zinc contamination.

In accordance with DGGE fingerprint in-depth study has been gained the molecular information of soil bacterium. At the same time the experiment used the traditional method to isolate ten strains resistant bacteria in lead and zinc contaminated mining soil, two s trains bacterium were identified as Bacillus pumilus and Pseudomonas aeruginosa through morphological ,physiological