Li Yusen, Chen Wenjian, Han Yaoquan, Lei Jianjun, Huang Bo, Qin Youjie, Lin Feng, Li Caijin, Wang Dapeng, Zhou Lei
Key Laboratory of Aquaculture Genetic and Breeding and Healthy Aquaculture of Guangxi, Guangxi Academy of Fishery Sciences, Nanning 530021, China.
China (Guangxi)-ASEAN Key Laboratory of Comprehensive Exploitation and Utilization of Aquatic Germplasm Resources, Ministry of Agriculture and Rural Affairs, Guangxi Academy of Fishery Sciences, Nanning 530021, China.
Microorganisms. 2025 Jul 12;13(7):1650. doi: 10.3390/microorganisms13071650.
Understanding the processes that drive microbial community assembly is a fundamental question in ecology, with important implications for predicting community responses to environmental disturbances. River ecosystems are under growing pressure from human disturbances, jeopardizing their ecological functions. Here, we investigated bacterial and protistan communities along the Yujiang River using environmental DNA metabarcoding. Bacterial communities exhibited significantly greater alpha diversity and broader habitat niches compared to protists. Additionally, a negative correlation was found between alpha diversity and niche breadth for both groups. Protistan communities exhibited significantly higher beta diversity (Bray-Curtis distance) than bacterial communities, with species turnover being the principal factor driving the variations in both communities. Null model results indicated that heterogeneous selection primarily structured bacterial communities, while stochastic processes (drift) mainly governed protist communities. Redundancy analysis and Mantel tests showed significant associations between environmental factors (e.g., temperature and pH) and bacterial community composition. Moreover, the longitude of sampling sites was linked to spatial variations in both bacterial and protistan communities. Further analyses, including distance-decay patterns, variation partitioning, and multiple regression on distance matrices, demonstrated that bacterial communities were driven by both environmental and spatial factors, while protist communities exhibited a stronger response to spatial factors. These results enhance our understanding of microbial community assembly in river ecosystems and provide valuable insights for the conservation and sustainable management of freshwater systems.
了解驱动微生物群落组装的过程是生态学中的一个基本问题，对预测群落对环境干扰的反应具有重要意义。河流生态系统受到人类干扰的压力越来越大，危及它们的生态功能。在这里，我们使用环境DNA宏条形码技术研究了郁江沿线的细菌和原生生物群落。与原生生物相比，细菌群落表现出显著更高的α多样性和更广泛的栖息地生态位。此外，两组的α多样性和生态位宽度之间均呈负相关。原生生物群落的β多样性（Bray-Curtis距离）显著高于细菌群落，物种更替是驱动两个群落变化的主要因素。零模型结果表明，异质性选择主要构建了细菌群落的结构，而随机过程（漂移）主要控制着原生生物群落。冗余分析和Mantel检验表明，环境因素（如温度和pH值）与细菌群落组成之间存在显著关联。此外，采样点的经度与细菌和原生生物群落的空间变化有关。进一步的分析，包括距离衰减模式、变异分解和距离矩阵的多元回归，表明细菌群落受环境和空间因素的驱动，而原生生物群落对空间因素的反应更强。这些结果增进了我们对河流生态系统中微生物群落组装的理解，并为淡水系统的保护和可持续管理提供了有价值的见解。
