State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, PR China.
Key Laboratory of Poyang Lake Environment and Resource Utilization, Ministry of Education, School of Environmental and Chemical Engineering, Nanchang University, Nanchang 330000, PR China.
Bioresour Technol. 2024 Nov;412:131369. doi: 10.1016/j.biortech.2024.131369. Epub 2024 Aug 28.
Signal-molecule-mediated strategies are proposed for aerobic granular sludge (AGS), but the regulatory mechanisms behind AGS formation are largely unexplored. In this study, two sequence batch reactors (SBRs) were operated to investigate the regulation of diffusible signal factor (DSF) in AGS formation. DSF secretion in Reactor 2 (R2: 10 °C→25 °C) decreased by 15 % compared to Reactor 1 (R1: 25 °C→10 °C), correlating with a 26 % increase in extracellular polymeric substance (EPS) concentration, resulting in a 63 % acceleration of the granulation process. After temperature shocks in R2, DSF concentration increased by 70 %, while EPS concentration decreased by 47 %. Batch tests confirmed that DSF inhibited EPS secretion. Combined 16S rRNA analysis and machine learning identified key bacteria responsible for secreting EPS and signal molecule. The decrease in the abundances of these bacteria reduced EPS production. These findings on DSF regulation of EPS secretion provide an in-depth understanding of enhanced AGS granulation.
目前提出了基于信号分子的策略来培养好氧颗粒污泥（AGS），但 AGS 形成背后的调控机制在很大程度上仍未得到探索。本研究采用两个序批式反应器（SBR）来研究可扩散信号因子（DSF）在 AGS 形成中的调控作用。与反应器 1（R1：25°C→10°C）相比，反应器 2（R2：10°C→25°C）中 DSF 的分泌量降低了 15%，这与胞外聚合物（EPS）浓度增加 26%相关，从而使颗粒化过程加速了 63%。在 R2 中进行温度冲击后，DSF 浓度增加了 70%，而 EPS 浓度降低了 47%。批式实验证实 DSF 抑制了 EPS 的分泌。结合 16S rRNA 分析和机器学习，确定了负责分泌 EPS 和信号分子的关键细菌。这些细菌丰度的降低减少了 EPS 的产生。这些关于 DSF 对 EPS 分泌调控作用的发现为增强 AGS 颗粒化提供了深入的理解。
