Department of Civil and Environmental Engineering, University of Toledo, Mail Stop 307, 3048 Nitschke Hall, Toledo, OH, USA.
Institute for Environmental Genomics and Department of Botany and Microbiology, University of Oklahoma, Norman, OK, USA.
Sci Total Environ. 2021 Jan 10;751:141409. doi: 10.1016/j.scitotenv.2020.141409. Epub 2020 Aug 8.
To address the adverse effects of harmful algal blooms, there are increased demands over the implementation of ozone coupled with biologically active carbon (BAC) filters in the drinking water treatment plants. Although the microbial biofilms are vital elements to support the proper performance of BAC filters, except for taxonomic affiliations, little is known about the assembly mechanisms of microbial communities in the full-scale BAC filters. This study aimed to examine how the assembly processes and their associated factors (e.g., influent characteristics, biological interactions) drive the temporal dynamics of bacterial communities in full-scale BAC filters, which underwent ozone implementation (five consecutive seasons from 2017 to 2018). The results revealed that along with the increase of bacterial taxonomic richness and evenness, stochastic processes became more crucial to determine the bacterial community assembly in the summer and autumn after ozone implementation (relative contribution: 61.23% and 83.75%, respectively). Moreover, their corresponding networks possessed simple network structures with lower modularity than other seasons, which implied lesser biological interactions among bacterial populations. The correlation between taxonomic and predicted functional diversities using functional redundancy index indicated that relatively high levels of bacterial functional redundancy (>0.83) were generally present in BAC filters. However, compared to other seasons, significantly higher degrees of functional redundancy existed in the summer and autumn after ozone implementation (0.85 ± 0.01 and 0.86 ± 0.01, respectively). Overall, this work improves our understanding of the microbial ecology of full-scale BAC filters by providing a conceptual framework that characterizes bacterial biofilm assembly processes relevant to performance optimization of full-scale BAC filters.
为了解决有害藻类水华的不利影响，在饮用水处理厂中增加了臭氧与生物活性炭（BAC）过滤器联用的需求。尽管微生物生物膜是支持 BAC 过滤器正常运行的重要因素，但除了分类学隶属关系外，对于大规模 BAC 过滤器中微生物群落的组装机制知之甚少。本研究旨在探讨组装过程及其相关因素（例如进水特性、生物相互作用）如何驱动大规模 BAC 过滤器中细菌群落的时间动态，这些过滤器经历了臭氧的实施（2017 年至 2018 年连续五个季节）。结果表明，随着细菌分类丰富度和均匀度的增加，随机过程对臭氧实施后夏季和秋季细菌群落组装的决定性作用变得更加重要（相对贡献分别为 61.23%和 83.75%）。此外，它们相应的网络具有简单的网络结构，与其他季节相比，模块性较低，这意味着细菌种群之间的生物相互作用较少。使用功能冗余指数对分类和预测功能多样性之间的相关性表明，BAC 过滤器中通常存在相对较高水平的细菌功能冗余（>0.83）。然而，与其他季节相比，臭氧实施后夏季和秋季的功能冗余程度显著更高（分别为 0.85±0.01 和 0.86±0.01）。总的来说，这项工作通过提供一个概念框架，描述了与大规模 BAC 过滤器性能优化相关的细菌生物膜组装过程，从而提高了我们对大规模 BAC 过滤器微生物生态学的理解。
