CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China; University of Chinese Academy of Sciences, Beijing, 100049, China; Fujian Key Laboratory of Watershed Ecology, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China; Laboratory of Physical Chemistry, University of Abomey-Calavi, 01 BP 4521, Cotonou, Benin, Benin.
CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China; University of Chinese Academy of Sciences, Beijing, 100049, China; Fujian Key Laboratory of Watershed Ecology, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China; Department of Environmental Engineering, Universitas Pertamina, Jakarta, 12220, Indonesia.
J Environ Manage. 2023 Sep 1;341:117986. doi: 10.1016/j.jenvman.2023.117986. Epub 2023 May 10.
Increased urbanization and anthropogenic activities can alter dissolved organic matter (DOM) and complicate its interaction with bacteria in rivers' ecosystems, however, there is limited information about how bacterial communities respond to DOM components in rivers with different urbanization levels. Here, we combined spectroscopy-based DOM analysis and 16S rRNA gene amplicon sequencing to investigate the associations of bacterial taxa and DOM properties as well as the impacts of DOM on bacterial niche breadth in North River (NR) and West River (WR) of Jiulong River watershed, southern China, which had low and high urbanization levels, respectively. Spectroscopy analysis showed that hydrophilic DOM was predominant in both rivers whereas chromophoric DOM was higher in WR. Network analysis indicated that only seven bacterial genera (i.e., hg clade, chthoniobacter, Geobacter, Acidibacter, Alphal Cluster, Fluviicola, and Lacunisphaera) showed strong associations with DOM optical variables in both rivers, whereas more than 85% of DOM-bacterial genera associations were different between rivers. These results suggest that the relationship between DOM and bacterial communities had different responses in rivers with different urbanization levels. The partial least square path model indicated that the total standardized effect of physico-chemicals on bacterial niche breadth was higher in NR (0.62) than in WR (0.35), whereas humic substances showed an opposite pattern (NR: -0.42; WR: 1.67). The distinct effects of physico-chemicals and DOM on bacterial niche breadths between rivers could be due to the different effects of urbanization and human activities on the environmental conditions of riverine ecosystems. Our findings revealed a huge dissimilarity in the bacteria-DOM co-occurrence networks between rivers with different urbanization levels and provide a novel insight that urbanization may enhance DOM's importance to bacterial niche breadths.
城市化和人为活动的增加会改变溶解有机物质（DOM）并使其与河流生态系统中的细菌相互作用复杂化，然而，关于不同城市化水平的河流中细菌群落对 DOM 成分的响应，信息有限。在这里，我们结合基于光谱的 DOM 分析和 16S rRNA 基因扩增子测序，研究了细菌分类群与 DOM 特性的关联，以及 DOM 对中国南方九龙江流域北江（NR）和西江（WR）细菌生态位广度的影响，这两条河的城市化水平分别较低和较高。光谱分析表明，亲水性 DOM 在两条河流中均占优势，而 WR 中的发色 DOM 较高。网络分析表明，只有七个细菌属（即 hg 群，chthoniobacter，Geobacter，Acidibacter，Alphal Cluster，Fluviicola 和 Lacunisphaera）与两条河流中的 DOM 光学变量表现出强烈的关联，而 DOM-细菌属之间的关联在河流之间有 85%以上的差异。这些结果表明，DOM 与细菌群落之间的关系在不同城市化水平的河流中具有不同的响应。偏最小二乘路径模型表明，理化因素对细菌生态位广度的总标准化效应在 NR（0.62）中高于 WR（0.35），而腐殖质则表现出相反的模式（NR：-0.42；WR：1.67）。河流之间理化因素和 DOM 对细菌生态位广度的不同影响可能是由于城市化和人类活动对河流生态系统环境条件的不同影响。我们的研究结果揭示了不同城市化水平河流中细菌-DOM 共同发生网络的巨大差异，并提供了一个新的见解，即城市化可能增强 DOM 对细菌生态位广度的重要性。
Zotero 插件