Mohamed A Y A, Gill Laurence, Monleon Alejandro, Pronk Mario, van Loosdrecht Mark, Saikaly Pascal E, Ali Muhammad
Department of Civil, Structural & Environmental Engineering, Trinity College Dublin, The University of Dublin, Dublin D2, Ireland.
Department of Biotechnology, Delft University of Technology, Delft 2629 HZ, The Netherlands.
Environ Sci Technol. 2025 Apr 1;59(12):6126-6141. doi: 10.1021/acs.est.4c14471. Epub 2025 Mar 19.
Understanding the relative influence of immigration and species sorting in wastewater treatment systems is essential, as bacteria in influent wastewater can significantly impact treatment system functionality. This study investigated the contribution of immigration to the community assembly of different-sized microbial aggregates in a full-scale aerobic granular sludge (AGS) system using genome-resolved metatranscriptomics. Our novel analysis revealed that negative-net-growth-rate populations, which persist due to immigration, can exhibit substantial activity and potentially contribute to the AGS system's functionality. The results also highlighted that sulfate-reducing and fermenting bacteria, along with some nitrifiers and glycogen-accumulating organisms (GAOs), were more active in the influent wastewater, serving as a continuous source of both beneficial and competing immigrants to the AGS system. Granular sludge (size >0.2 mm) demonstrated a robust capacity to resist immigration effects from competing immigrants, whereas flocculent sludge (size <0.2 mm) was more susceptible. Importantly, flocculent sludge harbored functional microbial groups such as active nitrifiers and fermentative polyphosphate-accumulating organisms (PAOs) belonging to , while granular sludge enriched for active conventional PAOs such as . These findings provide valuable insights for engineers to design and operate AGS systems by optimizing microbial aggregate sizes and emphasizing the importance of influent microbial characterization in the design of wastewater treatment plants to enhance the functionality and activity of AGS systems.
了解移民和物种分选在废水处理系统中的相对影响至关重要，因为进水废水中的细菌会显著影响处理系统的功能。本研究使用基因组解析宏转录组学方法，调查了在一个全尺寸好氧颗粒污泥（AGS）系统中，移民对不同大小微生物聚集体群落组装的贡献。我们的新分析表明，由于移民而持续存在的负净生长率种群可以表现出大量活性，并可能对AGS系统的功能做出贡献。结果还突出显示，硫酸盐还原菌和发酵菌，以及一些硝化菌和糖原积累生物体（GAOs）在进水废水中更为活跃，它们是AGS系统中有益和竞争性移民的持续来源。颗粒污泥（尺寸>0.2毫米）表现出强大的能力来抵抗来自竞争性移民的移民影响，而絮凝污泥（尺寸<0.2毫米）则更易受影响。重要的是，絮凝污泥中含有功能性微生物群体，如属于的活性硝化菌和发酵性聚磷菌（PAOs），而颗粒污泥则富集了如的活性传统PAOs。这些发现为工程师通过优化微生物聚集体大小来设计和运行AGS系统提供了有价值的见解，并强调了在废水处理厂设计中进水微生物特征分析对于增强AGS系统功能和活性的重要性。
