Hubei Key Laboratory of Wetland Evolution & Ecological Restoration, School of Environmental Studies, China University of Geosciences, Wuhan 430074, Hubei, China.
Hubei Key Laboratory of Wetland Evolution & Ecological Restoration, School of Environmental Studies, China University of Geosciences, Wuhan 430074, Hubei, China; State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, Hubei, China.
Sci Total Environ. 2022 Dec 10;851(Pt 1):158192. doi: 10.1016/j.scitotenv.2022.158192. Epub 2022 Aug 19.
The exploitation of polymetallic deposits produces large amounts of mine drainage, which poses great challenges to the surrounding aquatic ecosystem. However, the prokaryotic microbial community assembly and co-existence patterns in the polluted area are poorly understood, especially in high-altitude localities. Herein, we investigated the prokaryotic microbial assembly, co-existence patterns and their potential functional responses in surrounding river sediments of a Cu-polymetallic deposit in Tibet. The sediments from mine drainage and surrounding tributaries exhibited distinct geochemical gradients, especially the changes in Cu content. The microbial community structure changed significantly, accompanied by decreased richness and diversity with increased Cu content. Interestingly, the relative abundances of some potential functional bacteria (e.g., Planctomycetota) actually increased as the Cu levels raised. In low contaminated area, ecological drift was the most important assembly process, whereas deterministic processes gained importance with pollution levels. Meanwhile, negative interactions in co-occurrence networks were more frequent with higher modularity and reduced keystone taxa in high contaminated area. Notably, the functions related to ABC transporters and quorum sensing (QS) were more abundant with high Cu content, which helped bacteria work together to cope with the stressful environment. Taken together, the physicochemical gradients dominated by Cu content drove the distribution, assembly and co-existence patterns of microbial communities in surrounding river sediments of a Cu-polymetallic deposit. These findings provide new insights into the maintenance mechanisms of prokaryotic microbial communities in response to heavy metal stress at high altitudes.
多金属矿床的开采会产生大量的矿山排水，这对周围的水生生态系统构成了巨大的挑战。然而，受污染地区的原核微生物群落组装和共存模式仍知之甚少，尤其是在高海拔地区。在此，我们研究了西藏某铜多金属矿床周围河流沉积物中原核微生物的组装、共存模式及其潜在的功能响应。矿山排水和周围支流的沉积物表现出明显的地球化学梯度，特别是铜含量的变化。微生物群落结构发生了显著变化，随着铜含量的增加，丰富度和多样性降低。有趣的是，一些潜在功能细菌（如浮霉菌门）的相对丰度实际上随着铜水平的升高而增加。在低污染区，生态漂移是最重要的组装过程，而随着污染水平的升高，确定性过程变得更加重要。同时，在高污染区，共生网络中的负相互作用更为频繁，模块性更高，关键种减少。值得注意的是，与 ABC 转运蛋白和群体感应（QS）相关的功能在高铜含量下更为丰富，这有助于细菌共同应对恶劣环境。总之，以铜含量为主导的物理化学梯度驱动了铜多金属矿床周围河流沉积物中原核微生物群落的分布、组装和共存模式。这些发现为高海拔地区重金属胁迫下原核微生物群落的维持机制提供了新的见解。
