区域地下水不同深度微生物群落结构特征

为了揭示区域地下水不同深度微生物群落结构特征及其与地下水环境相互作用关系，选取北京琉璃河地区，采集不同深度地下水样品，用于水化学分析和微生物16S rRNA基因V4-V5区测序.水化学分析结果显示，地下水中8种主要离子浓度随深度增加均呈减小趋势，Cl^-、SO₄^2-、NO₃^-变化规律显著，工业较发达区NO₃^-浓度达155.30mg/L，SO₄^2-浓度达321.00mg/L，部分浅层地下水受NO₃^-和SO₄^2-污染.微生物分析结果显示，地下水中微生物群落多样性受深度影响显著，随深度增加微生物群落组成丰富.地下水中优势菌门为Proteobacteria （26.2%~95.2%），优势菌属为Pseudomonas（1.5%~32.2%），不同深度微生物菌属组成差异明显，浅层、中层和深层地下水特有菌属数目分别为74，60，54.NO₃^-、SO₄^2-、深度是影响地下水微生物群落的主要因子，且NO₃^-、SO₄^2-浓度受地下水深度影响程度大.地下水深度是影响微生物群落结构差异的重要原因.

Structure characteristics of microbial community at different depths of groundwater

To reveal the structure characteristics of microbial communities in regional groundwater at different depths and the interaction between microbial communities and groundwater environment, Liuli River district located in the southwestern Beijing was selected to collect different deep groundwater samples for the hydrochemical analysis and the high-throughput sequencing of the V4-V5region of microbial 16S rRNA. The results of hydrochemistry showed that the concentration of eight main ions decreased with the increase of depth in groundwater, especially Cl^-, SO₄^2- and NO₃^- varied obviously. In industrial area, the highest concentrations of NO₃^- and SO₄^2- were up to 155.30mg/L and 321.00mg/L, respectively, where shallow groundwater was contaminated with NO₃^- and SO₄^2-. Microbial analysis showed that the diversity of microbial community was strongly affected by groundwater depth, and microbial abundance increased with the increase of groundwater depth. Proteobacteria(26.2%~95.2%)was the dominant phylum and Pseudomonas (1.5%~32.2%)was the dominant genus. The microbial community at different depths of groundwater was significantly different. The number of the specific genera of shallow, middle and deep aquifer were 74, 60 and 54, respectively. NO₃^-, SO₄^2-and depth were the main factors affecting the microbial community. In addition, the concentrations of NO₃^- and SO₄^2- were closely related to depth. Groundwater depth was an important control factor to microbial community structure.