中文摘要：

自然界中氮循环与微生物的作用密不可分．在过去的几年里，随着异养硝化、厌氧氨氧化和古菌氨氧化过程的发现，人们对氮循环的认识发生了明显的变化．就异养硝化菌、厌氧氨氧化菌和氨氧化古菌的发现、生化机理及分子生物学等方面进行综述，旨在为今后人们重新认识和构建新的氮循环提供有用信息，并对这些新型微生物今后在污水生物脱氮处理中的应用提出了一些展望和设想．指出今后在污水生物处理系统中，可通过富集异养硝化菌强化同步硝化反硝化、富集厌氧氨氧化菌实现单级自养脱氮、富集氨氧化古菌提高低溶解氧下的脱氮效率．

英文摘要：

The global nitrogen cycle is driven by a series of microbial activities. In the past few years, the understanding of nitrogen cycling processes has changed dramatically based on some new processes, including heterotrophic nitrification, anaerobic ammonium oxidation （Anammox） and archaeal ammonia oxidation. In this review, the discovery, biochemistry mechanism and molecular biology of organisms linked to these processes are presented and relevant unknown questions are highlighted. A new nitrogen cycle will only emerge through considering all of these processes and microbial groups together. In addition, the paper presents some new perspectives about the application of these new organisms in biological nitrogen removal from wastewater. These new perspectives include enriching heterotrophic nitrification bacteria to enhance simultaneous nitrification-denitrification, enriching Anammox to achieve single-stage autotrophic nitrogen removal and enriching ammonia oxidation archaea to improve nitrogen removal efficiency at low dissolved oxygen （DO）.