介体调控反硝化生物膜形成及电子传递的机制解析

氮素污染会造成水体富营养化等重大污染现象，经济有效地控制氮素排放已成为我国环保发展的迫切需求。目前我国主流生物脱氮技术受限于反硝化速率较低，且存在氮素中间体积累的问题，亟需加深对生物脱氮过程的机理认识，开发更为高效生物脱氮技术。生物膜系统广泛应用于反硝化过程，其性能受生物膜形态及电子传递过程等多因素影响。氧化还原介体可调节微生物电子传递过程，并在生物膜内通过介体间电子交换实现快速长程电子传输。因此，氧化还原介体在反硝化生物膜体系中或能起到“电子桥梁”作用，调控反硝化生物膜的形成并重塑生物膜内电子传递网络。基于此，本项目拟以反硝化生物膜为研究对象,通过探索氧化还原介体对反硝化生物膜的形成、空间形态及微生物组分的影响规律，解析氧化还原介体介导电子传递过程与反硝化微生物呼吸途径间互作关系，进而揭示氧化还原介体对反硝化生物膜形成的调节效应机制，为提升生物脱氮工艺性能提供科学依据。

Nitrogen pollution can cause severe environmental problems such as eutrophication. It is an urgent need for an economical and effective control strategy to protect the natural environment. At present, the biological denitrification technologies in China are limited by low denitrification efficiency and accumulation of nitrogen-containing intermediates. Therefore, it is urgent to deepen the understanding of the microbial denitrification process mechanism and develop more efficient biological denitrification technologies. The biofilm system is widely used in the process of nitrogen removal. Its performance is affected by many factors, such as the morphology of the denitrifying biofilm and the electron transfer process. Redox mediators can regulate the electron transfer process of microorganisms and realize rapid and long-distance electron transport through electron hopping in biofilm. Therefore, the addition of redox mediators may play an “electron bridge” role in regulating the formation of denitrification biofilms and refactoring the electron transfer network in biofilms. In this study, we will examine the effects of different redox mediators on the formation, spatial morphology, and microbial community of biofilms, analyze the intrinsic relations between functional microbial metabolism and the electron transfer process in the presence of redox mediators, and reveal the roles of redox mediators in regulating denitrification biofilm formation. The results generated from this research will provide guidance and support for enhancing the performance of the denitrification process.