酸性矿山废水库周边土壤微生物多样性及氨氧化菌群落研究

Microbial Diversity and Ammonia-Oxidizing Microorganism of a Soil Sample Near an Acid Mine Drainage Lake

采集了安徽某铁矿酸性矿山废水库周边土壤样品,测定其理化参数,并采用分子生物学方法分别研究了土壤中细菌和古菌群落组成以及驱动氨氧化作用的微生物类群.结果表明,该土壤样品受到酸性矿山废水严重污染,pH低于3,铁铝等金属含量很高.细菌的16S rRNA基因文库覆盖11个类群,其中酸杆菌门(Acidobacteria)占主导地位,丰度达47.4%;疣微菌门(Verrucomicrobia)为第二大门类,丰度为18.9%.样品中含有大量嗜酸的细菌类群,如Candidatus Koribacter versatilis和Holophaga sp.等.古菌的16S rRNA基因文库仅覆盖2个类群,分别为奇古菌门(Thaumarchaeota)和广古菌门(Euryarchaeota),奇古菌门占绝对优势地位.该土壤样品中的氨氧化作用可能主要由奇古菌门的氨氧化古菌所驱动,且该区域存在新的氨氧化古菌类群.

The main physicochemical parameters of the soil sample which was collected near an acid mine drainage reservoir in Anhui province was analyzed. The microbial diversity and community structure was studied through the construction of bacteria and archaea16S rRNA gene clone libraries and ammonia monooxygenase gene clone library of archaea. The functional groups which were responsible for the process of ammonia oxidation were also discussed. The results indicated that the soil sample had extreme low pH value( pH < 3) and high ions concentration,which was influenced by the acid mine drainage( AMD). All the 16S rRNA gene sequences of bacteria clone library fell into 11 phyla,and Acidobacteria played the most significant role in the ecosystem followed by Verrucomicrobia. A great number of acidophilic bacteria existed in the soil sample,such as Candidatus Koribacter versatilis and Holophaga sp.. The archaea clone library consisted of 2 phyla( Thaumarchaeota and Euryarchaeota). The abundance of Thaumarchaeota was remarkably higher than Euryarchaeota. The ammonia oxidation in the soil environment was probably driven by ammonia-oxidizing archaea,and new species of ammonia-oxidizing archaea existed in the soil sample.