Adaptive shifts of bacterioplankton communities in response to nitrogen enrichment in a highly polluted river.
Adaptive shifts of bacterioplankton communities in response to nitrogen enrichment in a highly polluted river.
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DOI：
10.1016/j.envpol.2018.11.002
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发表时间：
2019-02
影响因子：
8.9
通讯作者：
Yuzhan Yang;Yangchun Gao;Xuena Huang;P. Ni;Yueni Wu;Ye Deng;Aibin Zhan
中科院分区：
文献类型：
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作者：
Yuzhan Yang;Yangchun Gao;Xuena Huang;P. Ni;Yueni Wu;Ye Deng;Aibin Zhan
人类活动引起的营养盐污染，尤其是氮富集，是河流生态系统面临的主要威胁之一。然而，目前尚不清楚它如何以及在多大程度上影响水生微生物群落，特别是在污染严重的河流中。在这项研究中，一个显着的环境梯度，特别是氮梯度，观察沿着的废水接收河流，北运河河（NCR）。污染水平分别为上游最高、中游中等和下游最低。浮游细菌群落组成由上游以β-变形菌为主向下游以γ-变形菌为主过渡。共营养类群中，多核菌（β-变形菌门）和噬氢菌（β-变形菌门）在上游占优势。多元统计分析表明，总氮是影响群落结构适应性变化的最重要因子。共现网络的分析表明，网络的复杂性在上游和中游被破坏，而在下游增强。我们的研究结果表明，微生物的相互作用减少，以应对营养污染的加重。与这些变化相似，我们观察到功能基团的组成显着不同，在最高水平的氮富集下，氮代谢成员的丰度最高。进一步分析表明，这些功能群大多属于β-变形菌，表明群落组成与功能多样性之间存在潜在的耦合。总之，浮游细菌群落组成的适应性变化，以及物种间的相互作用，发生在高度污染的水体中的营养盐污染。
Anthropogenic activity-mediated nutrient pollution, especially nitrogen enrichment, poses one of the major threats to river ecosystems. However, it remains unclear how and to which extent it affects aquatic microbial communities, especially in heavily polluted rivers. In this study, a significant environmental gradient, particularly nitrogen gradient, was observed along a wastewater receiving river, the North Canal River (NCR). The pollution level was highest, moderate, and lowest in the up-, middle, and down-streams, respectively. The community composition of bacterioplankton transitioned from beingBetaproteobacteria-dominated upstream toGammaproteobacteria-dominated downstream. Copiotrophic groups, such asPolynucleobacter(Betaproteobacteria) andHydrogenophaga(Betaproteobacteria), were dominant in the upstream. Multiple statistical analyses indicated that total nitrogen (TN) was the most important factor driving the adaptive shifts of community structure. Analyses of co-occurrence networks showed that the complexity of networks was disrupted in the up- and middle streams, while enhanced in the downstream. Our findings here suggested that microbial interactions were reduced in response to the aggravation of nutrient pollution. Similar to these changes, we observed significant dissimilarity of composition of functional groups, with highest abundance of nitrogen metabolism members under the highest level of nitrogen enrichment. Further analyses indicated that most of these functional groups belonged toBetaproteobacteria, suggesting the potential coupling of community composition and function diversity. In summary, adaptive shifts of bacterioplankton community composition, as well as species interactions, occurred in response to nutrient pollution in highly polluted water bodies.