厌氧消化系统中丙酸氧化互营共培养体的协同代谢与种间电子传递机制解析

Propionic acid accumulation in anaerobic digestor can cause acidification and it has been known as an important factor that restricts process efficiency and operational stability. It is thought that enhancing the function of the propionate-oxidizing bacteria is a feasible strategy to improve the efficiency of anaerobic biological treatment system. And the study of the mechanism of mutual co-cultured microorganisms and analysis of the catabolism and interspecies electron transfer mechanism of the syntrophic propionate-oxidizing co-culture is the breakthrough point for developing effective anaerobic wastewater treatment technology. In this research program, syntrophic propionate-oxidizing co-culture was first constructed, and using the batch and continuous flowing operation experiment, and then adopting the metagenomics and other means to resolve the distribution of functional microbial community responding to the change of the environmental factors, and analysis the mechanism of the interspecies electron transfer of the syntrophic propionate-oxidizing co-culture. At the same time, this study also using the model bacteria strain to construct “model microbial community” and “electronic conduction simulation system”, in order to verify cell communication mechanisms and collaborative behavior during the extracellular electron transfering process within different functional types of microbes. At last, the study also investigate the key enzyme repression of syntrophic propionate-oxidizing co-culture, in order to provide a theoretical basis and technical basis for guiding the application of wastewater treatment by anaerobic process.

丙酸积累引起的酸化问题一直是制约厌氧消化系统处理效能及运行稳定性的重要因素。对丙酸氧化菌群功能的强化，则是提高厌氧生物处理系统效能的有效调控对策。阐释厌氧体系中丙酸氧化互营共培养体的协同代谢和种间电子传递规律，是揭示丙酸氧化互营共培养体微生物学机理的根本，实现厌氧系统高效稳定运行的突破口。本课题以丙酸氧化互营共培养体的构建为基础，通过间歇培养与连续流反应器的运行实验，借助宏基因组学等多种手段，解析厌氧系统在不同环境压力条件下，丙酸互营共培养体中贡献电子和质子微生物的分布特征与演替规律，描述不同功能类型微生物的胞内电子传递特征。同时，利用模式菌株构建"模式微生物群落"和"电子传导模拟体系"，探明电子传递过程中，不同功能类型微生物之间的细胞通信机制及协作行为，揭示丙酸氧化互营共培养体协同代谢关键酶的诱导与阻遏机制，进而确立强化丙酸氧化菌群功能的定向调控策略，为厌氧系统的高效运行提供技术基础。

厌氧消化系统因丙酸积累引起的酸化问题一直是制约厌氧反应器处理效能及运行稳定性的重要因素。对丙酸氧化菌群功能的强化，则是提高厌氧生物处理系统效能的有效调控对策。阐释厌氧体系中丙酸氧化互营共培养体的协同代谢和种间电子传递规律，是揭示丙酸氧化互营共培养体微生物学机理的根本，实现厌氧系统高效稳定运行的突破口。本研究以丙酸氧化互营共培养体的构建为基础，通过连续流厌氧反应器的运行实验，探讨了厌氧系统运行中丙酸氧化菌群的演替规律，分析了丙酸互营共培养体中丙酸氧化菌群和产甲烷菌群的演替规律和种间电子传递机制，明晰了空间生态位及对生态因子的响应变化机制。通过间歇培养实验，成功构建丙酸氧化互营共培养体和筛选优势菌群，依此解析了厌氧系统在不同环境压力条件下的微生物响应变化和协同代谢机制。建立了厌氧消化系统中功能微生物的群体感应信号表征方法。本研究丰富了厌氧生物处理的微生物生理生态学理论，为强化互营丙酸氧化菌群功能的厌氧处理技术提供了支撑。