Wang Bin, Chen Qian, Liang Weihang, Chang Suyun, Sun Jingmei
School of Environmental Science and Engineering, Tianjin University, Tianjin, 300350, PR China.
School of Environmental Science and Engineering, Tianjin University, Tianjin, 300350, PR China; Tianjin Hydraulic Research Institute, Tianjin, 300061, PR China.
Environ Pollut. 2025 Oct 1;382:126741. doi: 10.1016/j.envpol.2025.126741. Epub 2025 Jun 27.
Understanding the distinct roles of rare (RT) and abundant taxa (AT) during the natural restoration of organic contaminated urban river sediments is crucial for optimizing bioremediation. This study investigated their distribution, assembly mechanisms, co-occurrence patterns, and functional traits across sediment pollution gradients. Results revealed that AT dominated in sequence abundance but comprised fewer OTUs, while RT exhibited higher α-diversity and broader niche width, underpinning community stability under pollution stress. Stochastic processes dominated community assembly, with dispersal limitation primarily shaping AT and ecological drift influencing RT. Functionally, AT drove pollutant transformation and energy metabolism, whereas RT displayed elevated metabolic activity supporting microbial growth. Critically, RT demonstrated superior xenobiotic biodegradation in severely polluted sediments, highlighting their specialized role in extreme conditions. Co-occurrence network emphasized RT's importance in maintaining complex microbial interactions, though network stability decreased with pollution. These findings demonstrate that AT and RT synergistically drive organic matter degradation, with RT uniquely contributing to pollutant breakdown and ecosystem stability under high pollution stress. This study provides insights into leveraging both taxa for optimized bioremediation strategies in contaminated sediments.
了解稀有类群（RT）和优势类群（AT）在有机污染城市河流沉积物自然修复过程中的不同作用，对于优化生物修复至关重要。本研究调查了它们在沉积物污染梯度上的分布、组装机制、共现模式和功能特征。结果表明，AT在序列丰度上占主导地位，但OTU数量较少，而RT表现出更高的α多样性和更宽的生态位宽度，这支撑了污染胁迫下群落的稳定性。随机过程主导群落组装，扩散限制主要塑造AT，生态漂变影响RT。在功能上，AT驱动污染物转化和能量代谢，而RT表现出更高的代谢活性以支持微生物生长。关键的是，RT在严重污染的沉积物中表现出卓越的异源生物降解能力，突出了它们在极端条件下的特殊作用。共现网络强调了RT在维持复杂微生物相互作用中的重要性，尽管网络稳定性随污染而降低。这些发现表明，AT和RT协同驱动有机物降解，RT在高污染胁迫下对污染物分解和生态系统稳定性有独特贡献。本研究为利用这两类群制定污染沉积物的优化生物修复策略提供了见解。
