Abstract: The nitrogen (N) pollution in water has become a serious problem for environment in China, and great effort has been taken to look for an efficient and economic method for N removal. In recent years, researchers have isolated many heterotrophic nitrifying and aerobic denitrifying bacteria from different environments. These functional bacteria showed tremendous potential for application by the reason of their rapid growth, simultaneously nitrifying and denitrifying under aerobic conditions and other organic pollutant removal. At present, the N removal pathway and mechanism of heterotrophic nitrification-aerobic denitrifying bacteria are mainly studied by assaying the intermediate or end product of N cycle, detecting the activity of related enzymes, annotating functional genes in N cycle and referring to the N cycle pathway of autotrophic nitrifying bacteria and anoxic denitrifying bacteria. The complete N conversion pathway and N metabolism mechanism should be further studied and determined. The progress on the related enzymes and their coding genes involved in N removal pathways of heterotrophic nitrification-aerobic denitrifying bacteria were summarized in order to provide reference for theoretical research of heterotrophic nitrifying-aerobic denitrifying bacteria and their application in wastewater denitrogenation.

Key words: heterotrophic nitrification, aerobic denitrification, nitrogen pollution, mechanism of nitrogen removal

摘要： 水体氮素污染日益严重，如何经济、高效地去除水体氮素已成为研究热点。近年来，研究人员已从不同环境中分离到许多同时具有异养硝化和好氧反硝化功能的菌株，此类菌生长迅速，可在好氧条件下同时实现硝化和反硝化的过程，并可用于脱除有机污染物，是一类应用潜力巨大的脱氮菌。目前，异养硝化-好氧反硝化菌的脱氮途径和机制主要是通过测定氮循环中间产物或终产物、测定相关酶活性、注释部分氮循环相关基因及参考自养硝化菌和缺氧反硝化菌的氮循环途径等进行研究，其完整的氮素转化途径和氮代谢机制还需要进一步明确。总结了目前异养硝化-好养反硝化菌的脱氮相关酶系及其编码基因的研究进展，以期为异养硝化-好氧反硝化菌的理论研究及其在污水脱氮处理上的应用提供参考。

关键词: 异养硝化, 好氧反硝化, 氮素污染, 脱氮机制