Novel nitrogen cycles in terrestrial and freshwater ecosystems

Abstract:

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.