State Key Laboratory of Pollution Control & Resource Reuse, School of the Environment, Nanjing University, Nanjing, China.
Institute for Environmental Research, ABBt - Aachen Biology and Biotechnology, RWTH Aachen University, Aachen, Germany.
Environ Pollut. 2018 Aug;239:189-197. doi: 10.1016/j.envpol.2018.03.099. Epub 2018 Apr 11.
Conventional assessment and evaluation of sediment quality are based on laboratory-based ecotoxicological and chemical measurements with lack of concern for ecological relevance. Microbiotas in sediment are responsive to pollutants and can be used as alternative ecological indicators of sediment pollutants; however, the linkage between the microbial ecology and ecotoxicological endpoints in response to sediment contamination has been poorly evaluated. Here, in situ microbiotas from the Three Gorges Reservoir (TGR) area of the Yangtze River were characterized by DNA metabarcoding approaches, and then, changes of in situ microbiotas were compared with the ecotoxicological endpoint, aryl hydrocarbon receptor (AhR) mediated activity, and level of polycyclic aromatic hydrocarbons (PAHs) in sediments. PAHs and organic pollutant mixtures mediating AhR activity had different effects on the structures of microbiotas. Specifically, Shannon indices of protistan communities were negatively correlated with the levels of AhR mediated activity and PAHs. The sediment AhR activity was positively correlated with the relative abundance of prokaryotic Acetobacteraceae, but had a negative correlation with protistan Oxytrichidae. Furthermore, a quantitative classification model was built to predict the level of AhR activity based on the relative abundances of Acetobacteraceae and Oxytrichidae. These results suggested that in situ Protista communities could provide a useful tool for monitoring and assessing ecological stressors. The observed responses of microbial community provided supplementary evidence to support that the AhR-active pollutants, such as PAHs, were the primary stressors of the aquatic community in TGR area.
传统的沉积物质量评估和评价是基于实验室的生态毒理学和化学测量，而缺乏对生态相关性的关注。沉积物中的微生物群落对污染物有反应，可以作为沉积物污染物的替代生态指标；然而，微生物生态学与对沉积物污染的生态毒理学终点之间的联系还没有得到很好的评估。在这里，利用 DNA 宏条形码方法对长江三峡库区的原位微生物群落进行了特征描述，然后比较了原位微生物群落的变化与生态毒理学终点（芳烃受体（AhR）介导的活性）和沉积物中多环芳烃（PAHs）的水平。PAHs 和有机污染物混合物介导的 AhR 活性对微生物群落的结构有不同的影响。具体来说，原生动物群落的 Shannon 指数与 AhR 介导的活性和 PAHs 的水平呈负相关。沉积物 AhR 活性与原核菌醋酸菌科的相对丰度呈正相关，但与原生动物腹毛目呈负相关。此外，还建立了一个定量分类模型，根据醋酸菌科和腹毛目相对丰度来预测 AhR 活性的水平。这些结果表明，原位原生动物群落可以为监测和评估生态胁迫提供有用的工具。微生物群落的观察到的反应提供了补充证据，支持了 AhR 活性污染物（如 PAHs）是三峡库区水生物群的主要胁迫物的观点。
