Shandong Yucheng Agro-Ecosystem National Observation and Research Station, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, 100101 Beijing, China; Sino-Danish College of University of Chinese Academy of Sciences, 101408 Beijing, China; Sino-Danish Centre for Education and Research, 101408 Beijing, China.
Shandong Yucheng Agro-Ecosystem National Observation and Research Station, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, 100101 Beijing, China; Sino-Danish College of University of Chinese Academy of Sciences, 101408 Beijing, China.
J Hazard Mater. 2023 Jun 5;451:131221. doi: 10.1016/j.jhazmat.2023.131221. Epub 2023 Mar 15.
Ion-adsorption rare earth mining results in the production of high levels of nitrogen, multiple metals, and strong acidic mine drainage (AMD), the impacts of which on microbial assembly and ecological functions remain unclear. To address this knowledge gap, we collected river sediments from the watershed of China's largest ion-adsorption rare earth mine and analyzed the bacterial community's structure, function, and assembly mechanisms. Results showed that bacterial community assembly was weakly affected by spatial dispersion, and dispersal limitation and homogeneous selection were the dominant ecological processes, with the latter increasing with pollution gradients. Bacterial alpha diversity decreased with pollution, which was mainly influenced by lead (Pb), pH, rare earth elements (REEs), and electrical conductivity (EC). However, bacteria developed survival strategies (i.e., enhanced acid tolerance and interspecific competition) to adapt to extreme environments, sustaining species diversity and community stability. Community structure and function showed a consistent response to the polluted environment (r = 0.662, P = 0.001). Enhanced environmental selection reshaped key microbial-mediated biogeochemical processes in the mining area, in particular weakening the potential for microbial denitrification. These findings provide new insights into the ecological response of microbes to compound pollution and offer theoretical support for proposing effective remediation and management strategies for polluted areas.
离子吸附型稀土矿开采导致产生了高浓度的氮、多种金属和强酸性矿山排水（AMD），但其对微生物组合和生态功能的影响仍不清楚。为了解决这一知识空白，我们从中国最大的离子吸附型稀土矿区的流域收集了河流沉积物，并分析了细菌群落的结构、功能和组装机制。结果表明，细菌群落的组装受空间扩散的影响较弱，扩散限制和均匀选择是主要的生态过程，后者随着污染梯度的增加而增加。细菌的α多样性随着污染而降低，主要受铅（Pb）、pH 值、稀土元素（REEs）和电导率（EC）的影响。然而，细菌发展出了生存策略（即增强了耐酸性和种间竞争）来适应极端环境，维持了物种多样性和群落稳定性。群落结构和功能对污染环境表现出一致的响应（r=0.662，P=0.001）。增强的环境选择重塑了矿区关键的微生物介导的生物地球化学过程，特别是削弱了微生物反硝化的潜力。这些发现为微生物对复合污染的生态响应提供了新的见解，并为提出污染区有效修复和管理策略提供了理论支持。
