重金属复合污染农田土壤的微生物群落遗传多样性研究

采集了浙江省富阳市环山乡某冶炼厂小高炉附近受铜、锌、铅、镉不同程度复合污染的4个农田土壤样品，首先扩增土壤总DNA中的16S rDNA，然后进行变性梯度凝胶电泳(Denaturing Gradient Gel Electrophoresis)，分析了长期受重金属复合污染的农田土壤的微生物群落遗传多样性变化．结果表明，不同程度的重金属复合污染明显改变了农田土壤的微生物群落遗传多样性，但与多样性的改变不是简单的负相关关系，最大的多样性指数出现在中等污染程度的土壤中．

Genetic diversity of microbial communities in farmland soils contaminated with mixed heavy metals

Four soil samples contaminated with the different levels of mixed heavy metals were collected from a nearby smelter and the soil DNA was extracted by FastPrep system from which fragments were amplified. The genetic diversity of the soil microbial communities was analyzed by DGGE (denaturing gradient gel electrophoresis) of a conservative region of 16S rRNA gene. The results indicated that the mixed heavy metal pollution affected soil microbial community diversity, but there were not the simply negative relations between mixed heavy metal contamination and genetic diversity of soil microbial communities, and the largest diversity indexes appeared in the moderate mixed polluted soil. The reason might be that heavy metals changed the competitive relationships among individuals of soil microbial community, which lead to the lose of the dominance of the original predominant populations, or that the bacteria resistant to heavy metals protected other more sensitive ones.