School of Resources and Environmental Engineering, Hefei University of Technology, Hefei, Anhui 230009, China; Key Laboratory of Nanominerals and Pollution Control of Anhui Higher Education Institutes, Hefei University of Technology, Hefei, Anhui 230009, China.
School of Resources and Environmental Engineering, Hefei University of Technology, Hefei, Anhui 230009, China; Key Laboratory of Nanominerals and Pollution Control of Anhui Higher Education Institutes, Hefei University of Technology, Hefei, Anhui 230009, China.
Water Res. 2021 Nov 1;206:117739. doi: 10.1016/j.watres.2021.117739. Epub 2021 Oct 7.
Acid mine drainage (AMD) lakes are typical hydrologic features caused by open pit mining and represent extreme ecosystems and environmental challenges. Little is known about microbial distribution and community assembly in AMD lakes, especially in deep layers. Here, we investigated prokaryotic microbial diversity and community assembly along a depth profile in a stratified AMD lake using 16S rRNA gene sequencing combined with multivariate ecological and statistical methods. The water column in the AMD lake exhibited tight geochemical gradients, with more acidic surface water. Coupled with vertical hydrochemical variations, prokaryotic microbial community structure changed significantly, and was accompanied by increased diversity with depth. In the surface water, heterogeneous selection was the most important assembly process, whereas stochastic processes gained importance with depth. Meanwhile, microbial co-occurrences, especially positive interactions, were more frequent in the stressful surface water with reduced network modularity and keystone taxa. The pH was identified as the key driver of microbial diversity and community assembly along the vertical profile based on random forest analysis. Taken together, environmental effects dominated by acid stress drove the community assembly and species coexistence that underpinned the spatial scaling patterns of AMD microbiota in the lake. These findings demonstrate the distinct heterogeneity of local prokaryotic microbial community in AMD lake, and provide new insights into the mechanism to maintain microbial diversity in extreme acidic environments.
酸性矿山排水（AMD）湖是由露天采矿引起的典型水文特征，代表了极端的生态系统和环境挑战。人们对 AMD 湖中微生物的分布和群落组装知之甚少，尤其是在深层。在这里，我们使用 16S rRNA 基因测序结合多元生态和统计方法，研究了分层 AMD 湖中沿深度剖面的原核微生物多样性和群落组装。AMD 湖的水柱具有紧密的地球化学梯度，表面水更酸性。加上垂直水化学变化，原核微生物群落结构发生了显著变化，随着深度的增加，多样性也增加了。在地表水层，异质选择是最重要的组装过程，而随着深度的增加，随机过程变得更加重要。同时，微生物的共现，特别是正相互作用，在压力较大的地表水层更为频繁，网络模块性和关键分类群减少。基于随机森林分析，确定 pH 值是垂直剖面微生物多样性和群落组装的关键驱动因素。总的来说，以酸胁迫为主的环境效应驱动了群落组装和物种共存，这支撑了湖泊 AMD 微生物组的空间尺度模式。这些发现表明 AMD 湖中局部原核微生物群落具有明显的异质性，并为维持极端酸性环境中微生物多样性的机制提供了新的见解。
