在生物脱氮除磷系统中，污泥膨胀现象仍频繁发生，对其诱因的深入探索是实现控制污泥膨胀的本质要求。本项目从微丝菌表面疏水性和群体感应特性两方面对系统中微丝菌的生理行为与污泥膨胀的相关性进行研究。设计合成不同疏水性识别微丝菌的荧光探针，运用密度泛函理论并结合传统识别方法研究微丝菌表面疏水性与生理行为的相关性；运用生物传感菌、LC-MS等方法建立系统内污泥膨胀发生过程中AHLs、AIPs、AI-2等信号分子的量化方法，考察系统内群体感应信号分子与微丝菌性态变化的相关性；采用FISH、PCR、高通量测序等技术，考察系统内微丝菌及伴生丝状菌等菌群演替特性；研究感应信号分子与微丝菌性态变化及与共生菌群之间的信使关系和演替规律；研究系统中微丝菌表面疏水性和群体感应特性对污泥膨胀影响机制。这对进一步加深理解丝状污泥膨胀发生的本质有重要意义。

The sludge bulking caused by filamentous bacteria still occurred frequently in the biological nitrogen and phosphorus removal system. In-depth study of its inducements is essential to control the sludge bulking. In this project, the physiological behaviors of Microthrix parvicella (M. parvicella) in system are investigated in terms of surface hydrophobicity and quorum sensing characteristics, and their correlation causing sludge bulking is investigated. The fluorescent probes with different hydrophobicity to identify M. parvicella are designed and prepared, Density Functional Theory is introduced to investigate the correlation between surface hydrophobicity and physical behaviors is studied combined with traditional identification method. The detection and quantification methods of AHLs, AIPs and AI-2 et al signalling molecules in sludge bulking of systems are established by biosensor, LC-MS et al techniques, and it is used to explore the correlation between quorum sensing signalling molecules and change in the property and morphology of M. parvicella. The population dynamics of M. parvicella and other filamentous bacteria in system are tested by fluorescence in situ hybridization (FISH), polymerase chain reaction (PCR) and high-throughput sequencing et al technology. The effects of signalling molecules on the changes in property and morphology of M. parvicella, messenger behavior and dynamic properties of other filamentous bacteria in system are investigated. Moreover, the mechanism on sludge bulking influenced by surface hydrophobicity and quorum sensing properties of M. parvicella in biological nitrogen and phosphorus removal system is investigated, which is great significant for further understand the essence of filamentous sludge bulking.