Microbially mediated anaerobic ammonium oxidation can be coupled to the reduction of various terminal electron acceptors. Redox-active natural organic matter (NOM) can serve as an extracellular electron acceptor or donor in microbial redox reactions. The coupling of the anaerobic ammonium oxidation process to the reduction of NOM (herein termed NOM-ammox) is thermodynamically feasible and evidence has been provided demonstrating its environmental occurrence. Ecosystems with fluctuating redox conditions such as paddy fields are favorable for maintaining the redox reactivity of NOM, and thus may promote NOM-ammox. Here, we synthesize recent literature on NOM-ammox and discuss how redox conditions could control this process at different spatial scales in paddy ecosystems. We conclude that the inherent redox properties of NOM and environmental redox fluctuations are key for fueling and regulating NOM-ammox in paddy ecosystems.

微生物介导的厌氧铵氧化可以与各种末端电子受体的还原相结合。具有氧化还原活性的天然有机物（NOM）可以作为微生物氧化还原反应中的细胞外电子受体或供体。厌氧氨氧化过程与 NOM（本文称为 NOM-氨氧化）还原的耦合在热力学上是可行的，并且已提供证据证明其环境发生。氧化还原条件波动的生态系统如稻田有利于维持NOM的氧化还原反应性，因此可能促进NOM-氨氧化。在这里，我们综合了有关 NOM-ammmox 的最新文献，并讨论了氧化还原条件如何在水稻生态系统的不同空间尺度上控制这一过程。