陆地和淡水生态系统新型微生物氮循环研究进展

Novel nitrogen cycles in terrestrial and freshwater ecosystems

氮生物地球化学循环是地球物质循环的重要枢纽,是决定陆地生态系统生产力水平、水资源安全、温室气体生成排放的关键过程。氮循环是由微生物介导的一系列复杂过程,不同形态、价态氮化合物的转化分别由相应的功能微生物驱动完成。随着厌氧氨氧化、完全氨氧化等新型氮转化过程的相继报道和发现更新了人们对氮循环的认识。本文综述了陆地和淡水生态系统中厌氧氨氧化(anammox)、硝酸盐异化还原为铵(DNRA)、完全氨氧化(comammox)等新型氮循环过程的发生机制、热区分布及环境效应,并总结了这三种氮循环的相互关系。

Nitrogen biogeochemical cycle is an important part of the global element cycle,and the key factor to affect the ecosystem productivity,safety of water resources,greenhouse gas emissions.Nitrogen cycle is a complex process mediated by microorganisms,and the transformation of different nitrogen forms is dominated by corresponding functional microorganisms.The recent findings of anaerobic ammonia oxidation(anammox)and complete ammonia oxidation(comammox)reshaped our understanding of nitrogen cycle.Here we summarize the occurrence,distribution and process mechanisms of anammox,comammox and dissimilatory nitrate reduction to ammonium(DNRA)processes in nature,especially in terrestrial and freshwater ecosystems,and review the interactions among the three newly developed cycles.