A/O生物膜系统酵母菌磷代谢调控机制及其磷结晶诱导效应研究

Developing of the theory and technology of phosphorus recovery from wastewater is one of the most important research direction of resource recovery from wastewater. Yeast is not only the crucial biological factor in the biogeochemical cycle of phosphorus, but also the main functional microorganism in the wastewater treatment process, so that it has great application potential and research value in the field of phosphorus recovery from wastewater. In preliminary work we found that the yeast could induce phosphate crystallization efficiently, but the relationship of the effect and function of regulation genes and enzymes expression in the phosphorus metabolism of yeast and the mechanism of phosphate crystallization induced by yeast phosphorus metabolism were still unclear. Therefore, in this project, by using modern molecular biology and genetic engineering technology, we are going to investigate the population and physiological and biochemical characteristics of the yeast in A/O biofilm system, and screen efficient phosphorus uptaking/releasing yeast strains, to illustrate the basic rules of phosphorus metabolism of typical yeast and the influence of signal induction factors, such as the environmental factors, operational conditions and the substrate type of yeast phosphatase, on regulation of phosphatase and phosphate transporters expression. And then, based on the understanding of the efficiency, operational condition and mechanisms of phosphate crystallization induced by yeast phosphorus metabolism, we can regulate the yeast phosphorus metabolism and optimize the condition of phosphate crystallization interface reaction, to carry out a novel process system and the technical route of phosphate crystallization improved by yeast, as well as to provide a useful reference for phosphorus removal and recovery from wastewater.

研究开发城市污水磷回收理论与技术，是污水处理资源化的重要发展方向。酵母菌不仅是磷地球化学循环的关键生物因子，也是污水处理中的主要功能微生物，在污水除磷及磷回收领域具有重要的应用潜力和研究价值。申请人在前期研究中发现，酵母菌能够有效促进磷结晶，但有关酵母菌磷代谢调控基因与酶系表达的效应关系、酵母菌磷代谢的磷结晶诱导机理等关键问题尚不清楚。因此，本项目拟利用现代分子生物学和基因工程技术，在系统揭示A/O生物膜酵母菌种群结构和生理生化特性的基础上，筛选高效聚磷/释磷酵母菌株，阐明其磷代谢基本规律，揭示环境因子、运行条件和底物类型等调控信号对酵母菌磷代谢酶系表达的效应关系与作用规律，解析酵母菌磷代谢对磷结晶的诱导效应和作用机理，进而调控酵母菌磷代谢过程，优化磷结晶微界面反应条件，构建酵母菌强化磷结晶反应器系统与技术路线，探索形成酵母菌强化磷结晶新工艺，为丰富和深化污水磷回收研究提供理论和技术参考。

随着我国社会经济的快速发展，城市化进程持续加快，含磷废水排放量不断增加，自然水体面临严峻的富营养化问题。与此同时，磷又是一种不可再生资源，因此，研发低成本、高效的磷去除及回收技术，对保护水生态系统安全和维持磷资源的可持续利用具有重要意义。针对结晶除磷技术处理低浓度含磷废水效率低以及传统生物除磷工艺运行稳定性差、磷回收率低等问题，本项目提出了通过酵母菌强化结晶协同处理低浓度含磷废水以同步实现磷的去除与回收的新思路，从交替运行的厌氧/好氧生物滤池中筛选出高效除磷酵母菌，通过酵母菌菌株的形态学特征、生理生化特性及分子生物学分析，研究揭示了A/O生物膜系统的酵母菌种群生态学特性；考察了不同环境因素(温度、pH、碳源种类、氨氮浓度、碳磷比、溶解氧等)对酵母菌除磷效能的影响作用规律；阐明了不同酵母菌除磷过程中磷的分布、胞外聚合物和细胞的除磷贡献率及磷的迁移转化途径；运用现代分子生物学技术揭示了不同底物诱导和环境胁迫条件下酵母菌磷酸酯酶调控机理及关键因子作用规律，阐明了酵母菌除磷机理；利用红外光谱分析、X射线衍射分析等技术，探究了典型酵母菌的磷代谢活动对于除磷过程的影响规律与促进机理；构建了酵母菌强化磷结晶反应器，考察了不同运行参数(如pH值、结晶时间、搅拌强度、氨氮浓度、镁磷比、磷浓度)对反应器除磷效能的影响，确定了最优反应参数，开发了基于高效酵母菌强化的磷回收新工艺，为丰富和深化废水磷回收理论提供了参考。