Wang Zhenyu, Liu Feifei, Li Enze, Yuan Yongqiang, Yang Yonggang, Xu Meiying, Qiu Rongliang
Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou, China.
Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China.
Front Microbiol. 2022 Sep 30;13:931585. doi: 10.3389/fmicb.2022.931585. eCollection 2022.
Over-aeration is a common remediation strategy for black and odorous water bodies, in which oxygen is introduced to impact aquatic microbial communities as an electron acceptor of high redox potential. In this study, black-odorous freshwater sediments were cultured for 9 weeks under aeration to investigate microbial covariations at different depths and time points. Based on community gene sequencing, the microbial covariations were visualized using phylogenetic microbial ecological networks (pMENs). In the spatial scale, we identified smaller and more compact pMENs across all layers compared with the anaerobic control sediments, in terms of network size, average node connectivity, and modularity. The aerated middle layer had the most connectors, the least module hubs, a network hub, shorter average path length, and predominantly positive covariations. In addition, a significant sulfate accumulation in the aerated middle layer indicated the most intense sulfide oxidation, possibly because aeration prompted sediment surface , known as cable bacteria, to reach the middle layer. In the time scale, similarly, aeration led to smaller pMEN sizes and higher portions of positive covariations. Therefore, we conclude that elevated dissolved oxygen at the water-sediment interface may impact not only the surface sediment but also the subsurface and/or deep sediment microbial communities mediated by microorganisms, particularly by .
过度曝气是黑臭水体常见的修复策略，即引入氧气作为具有高氧化还原电位的电子受体来影响水生微生物群落。在本研究中，对黑臭淡水沉积物进行了为期9周的曝气培养，以研究不同深度和时间点的微生物协变情况。基于群落基因测序，利用系统发育微生物生态网络（pMENs）对微生物协变情况进行可视化分析。在空间尺度上，就网络大小、平均节点连通性和模块性而言，与厌氧对照沉积物相比，我们在所有层面上都识别出更小、更紧凑的pMENs。曝气的中间层具有最多的连接点、最少的模块枢纽、一个网络枢纽、较短的平均路径长度，且主要为正协变。此外，曝气中间层中显著的硫酸盐积累表明硫化物氧化最为强烈，这可能是因为曝气促使沉积物表面（即索状细菌）到达中间层。在时间尺度上，同样地，曝气导致pMENs大小变小且正协变比例更高。因此，我们得出结论，水 - 沉积物界面处溶解氧的升高不仅可能影响表层沉积物，还可能影响由微生物介导的次表层和/或深层沉积物微生物群落，尤其是由……介导的群落。
