State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), Harbin Institute of Technology, 73 Huanghe Road, Nangang District, Harbin, 150090, People's Republic of China.
Appl Microbiol Biotechnol. 2016 Sep;100(18):7887-97. doi: 10.1007/s00253-016-7496-6. Epub 2016 Apr 18.
Solid retention time (SRT) is one of the most important operational parameters in membrane bioreactor (MBR), which significantly influences membrane fouling. It is widely recognized that SRT mainly changes biomass characteristics, and then, influences membrane fouling. Effect of SRT on quorum sensing (QS) in MBR, which could also influence fouling by coordinating biofilm formation, has not been reported. In this study, fouling, QS, soluble microbial products (SMP), and extracellular polymer substances (EPS) in MBRs operated under SRTs of 4, 10, and 40 days were investigated. The results showed that as SRT increased, the abundance of quorum quenching (QQ) bacteria increased, the quorum signal degradation activity of activated sludge increased, the concentrations of signal molecules in MBR decreased, the excretion of SMP and EPS decreased, and thus membrane biofouling was alleviated. Therefore, besides altering the biomass physiochemical properties, SRT also changed the balance between QS and QQ in MBR, and in this way, influenced membrane biofouling.
固体停留时间（SRT）是膜生物反应器（MBR）中最重要的操作参数之一，它对膜污染有显著影响。人们普遍认为，SRT 主要通过改变生物量特性，从而影响膜污染。然而，SRT 对 MBR 中群体感应（QS）的影响，以及它通过协调生物膜形成来影响污染的作用，尚未有报道。在这项研究中，考察了 SRT 分别为 4、10 和 40 天时，MBR 中的污染、QS、可溶性微生物产物（SMP）和胞外聚合物物质（EPS）。结果表明，随着 SRT 的增加，群体淬灭（QQ）细菌的丰度增加，活性污泥的群体信号降解活性增加，MBR 中信号分子的浓度降低，SMP 和 EPS 的排泄减少，从而减轻了膜生物污染。因此，除了改变生物量的理化性质外，SRT 还改变了 MBR 中 QS 和 QQ 之间的平衡，从而影响了膜生物污染。
