地下水波动带中细菌群落结构与水质响应关系

为揭示地下水波动带中细菌群落结构特征及其与地下水环境相互作用关系，选取哈尔滨市第一水源地作为研究区，采集地下水样品以及波动带不同深度（0~5m非饱和带和6~50m饱和带）含水介质样品，分别用于水化学分析和16S rRNA细菌高通量测序，依托冗余分析定量表述地下水质参数与细菌群落相关性.水化学分析结果显示，研究区地下水主要污染物为Fe、Mn、NH₄⁺和有机质，Fe、Mn超标与研究区特定地质背景有关，NH₄⁺和有机质主要来源于人类活动.微生物分析结果显示，非饱和带和饱和带的细菌群落结构差异性显著，非饱和带细菌群落丰度和多样性显著高于饱和带，Proteobacteria、Bacteroidetes、Actinobacteria、Firmicutes和Acidobacteria为研究区优势门，在非饱和带和饱和带的累积相对丰度分别为82.89%和98.64%.冗余分析（RDA）结果显示，门水平上非饱和带中与水质演化强相关的细菌类群是Bacteroidetes、Proteobacteria、Actinobacteria、Verrucomicrobia，贡献率分别为15%、14.8%、8.9%和5.2%；饱和带中对地下水质演化起主要作用的类群为Bacteroidetes、Acidobacteria、Actinobacteria和Firmicutes，贡献率分别为38.4%、19.0%、10.8%和9.1%.属水平上非饱和带中的Pseudomonas和饱和带中的Flavobacterium对Fe、Mn、NH₄⁺生物转化起主导作用.本研究为揭示地下水波动带中生物地球化学作用对地下水环境的影响提供了科学依据，对地下水污染修复具有重要的意义.

Response relationship between bacterial community structure and water quality in ground water fluctuating region

This study aimed to reveal the characteristics of the bacterial community structure in the groundwater fluctuating region and its interaction with the groundwater environment in the First Water Resource in Harbin, Northeast China. Groundwater samples were collected for water chemical analysis and aquifer media samples at different depths in the fluctuating region (0~5m unsaturated zone and 6~50m saturated zone) for bacterial community analysis by 16Sr RNA. Redundancy analysis was used to indicate the correlation between groundwater quality parameters and the bacterial community. The main groundwater pollutants in the study area were Fe, Mn, NH₄⁺ and organic matter. The excess of Fe and Mn was mainly related to the specific geological background of northeast China. The NH₄⁺ and organic matter were mainly derived from human activities. There was a significant difference in the bacterial community structure between the unsaturated and saturated zones, and the abundance and diversity of the bacterial community in unsaturated zone were significantly higher than those of the saturated zone. Proteobacteria, Bacteroidetes, Actinobacteria, Firmicutes and Acidobacteria were the dominant bacteria in the study area, for which the accumulative relative abundance in the unsaturated and saturated zones was 82.89% and 98.64%, respectively. Bacteroidetes, Proteobacteria, Actinobacteria and Verrucomicrobia were closely related to groundwater quality evolution at the phylum level in the unsaturated zone, with contribution rates of 15%, 14.8%, 8.9% and 5.2%, respectively. Bacteroidetes, Acidobacteria, Actinobacteria and Firmicutes played a major role in the groundwater quality evolution process in the saturated zone, with contributions of 38.4%, 19.0%, 10.8% and 9.1%, respectively. Both Pseudomonas in the unsaturated zone and Flavobacterium in the saturated zone had a critical influence on the biotransformation of Fe, Mn and NH₄⁺ at the genus level. This study provides a scientific basis for revealing the impact of biogeochemical effects on groundwater environment in groundwater fluctuating regions, and is of great relevance for groundwater pollution restoration.