太行山前平原浅层地下水污染的分子生物学响应特征——以滹沱河流域为例

The response characteristics of microbial diversity to shallow groundwater contamination in the piedmont of the Taihang Mountains using molecular biotechnologies: A case study of groundwater of Hutuo River Basin

分子生物学技术是地下水污染研究的前沿技术,常用于场地尺度,区域尺度罕见。以太行山前平原滹沱河流域的典型浅层地下水为研究对象,沿河布点采样67组,采用高通量测序技术,测定样品16S rDNA基因序列,以化学需氧量、硝酸盐、溶解性总固体为环境因子,分析与污染相关的微生物种群结构响应及功能性指示菌属。结果显示:采用累积概率分布法将样品分为背景(B)、硝酸盐污染(N)、有机污染(Y)3组,该分类阈值与地下水质量标准的Ⅲ类水阈值可较好对应;微生物群落丰富度为B组>N组>Y组,有机污染使微生物种群趋于单一,且与背景差异更大。有机污染功能性指示菌属为Acinetobacter,硝酸盐污染为Nitrospira。以上形成的分子生物学响应特征研究方法可为区域调查及修复提供技术方法理论依据。

In the groundwater contamination research, molecular biotechnologies are one of the cutting- edge technologies. This kind of technologies have been commonly used at site scale, but rarely applied at regional scale. The shallow groundwater in Hutuo River Basin was selected as the study subject, because of it is one of the typical regions in front of the Taihang Mountains. 67samples were collected along the river. The 16s rDNA gene sequences were tested by high- throughput sequencing technology. According to the environmental factors of NO3^-, COD and TDS, the microbial communities and the functional indicator microorganisms related to groundwater contamination were studied. The results showed that, using the cumulative probability distribution method, the samples were divided into three groups: background (B group), nitrate pollution (N group), and organic pollution (Y group). This grouping rule was close to the III water grade threshold in the quality standard of groundwater. The order of microbial community richness is B group > N group > Y group. The organic pollution could decrease the richness diversity of microbial communities, and the difference was more significant in comparison with background microorganisms. The functional indicator microorganisms related to organic pollution was Acinetobacter, and the functional indicator microorganisms related to nitrate pollution was Nitrospira. The molecular biotechnologies and analysis methods used in this research could provide the theoretical evidence for regional environmental investigation and bioremediation.