铅锌矿区重金属污染对微生物数量及放线菌群落结构的影响

采集四川省汉源县富泉乡万顺铅锌矿区5个不同重金属浓度的土壤样品,进行了微生物数量及放线菌多样性的研究。经分离、纯化得到43株不同的放线菌,然后对其进行BOXAIR-PCR和16SrDNAPCR-RFLP分析。结果表明,铅锌矿区重金属复合污染对土壤微生物数量有较大的影响,随着铅锌矿区重金属污染程度的加剧,土壤微生物的总数下降。相关性分析表明,重金属含量与细菌数量呈极显著负相关（P〈0.01）,与放线菌数量、真菌数量呈显著负相关（P〈0.05）。供试菌株的16SrDNA用HaeⅢ、HinfⅠ和TaqⅠ酶切后具有32种遗传图谱类型。BOXAIR-PCR的聚类结果表明在86%的水平上,所有菌株分为10个遗传类型,结果基本与16SrDNAPCR-RFLP聚类差异不大。来源于高重金属的含量样品的菌株基本聚在一起,可能是重金属含量影响了放线菌的分布。同时,16SrDNA序列聚类分析结合系统发育树分析表明链霉菌属是汉源铅锌矿区主要的放线菌属并且具有遗传多样性。

Response of Microbe Quantity and Actinomycetes Community of Heavy Metal Contaminated Soils in Lead-zinc Mine

To understand the influence of the heavy metal pollution on actinomycetes,the microbe quantity of soils,diversity and dominant microbial groups of actinomycetes were tested.Forty-three strains of actinomycetes in the lead-zinc mine soils were isolated from Fuquan town,Hanyuan country,Sichuan Province.The genetic diversity was evaluated by BOXAIR and 16S rDNA PCR-RFLP.The results indicated that heavy metals pollution had a significant impact on the number of soil microbes in lead-zinc district.With the intensification of heavy metal pollution levels,the total number of soil microorganisms declined.There was a very significant negative correlation between the number of bacteria and heavy metal content（P0.01）,whereas significant negative correlation for the number of fungi and actinomycetes（P0.05）.The strains used in numerical taxonomy were analyzed by 16S rDNA PCR-RFLP with three kinds of restriction endonucleases（HaeⅢ,HinfⅠand TaqⅠ） and had 32 genotypes.Based on the dendrograms generated by BOXAIR-PCR,the strains were divided into 10 groups at the similarity of 86%.In addition,BOXAIR-PCR and 16S rDNA PCR-RFLP clustering analysis showed that the strains isolated from soil samples with the high content of heavy metal clustered together.It could be concluded that Streptomyces was the dominant genus of actinomycetes at the lead-zinc mine in Hanyuan country and had high genetic diversity.