Ammonia-oxidizing archaeon (AOA) could play important roles for nitrogen removal in the bioreactors under conditions such as low pH and low dissolved oxygen. Therefore, enhancing ammonia oxidation capability of AOA has great significance for water and wastewater treatment, especially under conditions like low dissolved oxygen concentration. Utilizing a novel AOA strain SAT1, which was enriched from a wastewater treatment plant by our group, the effect of magnetic field on AOA’ s ammonia oxidation capability, its magnetotaxis and heredity were investigated in this study. Compared with control experiment, AOA’ s maximum nitrite-N formation rate during the cultivation increased by 56.8% (0.65 mgN/(L$d)) with 20 mT magnetic field. Also, it was testified that AOA possessed a certain magnetotaxis. However, results manifested that the enhancement of AOA’s ammonia oxidation capability was not heritable, that is, lost once the magnetic field was removed. Additionally, the possible mechanism of improving AOA’s ammonia oxidation capability by magnetic field was owing to the promotion of AOA single cells’ growth and fission, rather than the enhancement of their ammonia oxidation rates. The results shed light on the application of AOA and methods to enhance AOA’s ammonia oxidation capability, especially in wastewater treatment processes under certain conditions.

氨氧化古菌（AOA）在低pH和低溶解氧等条件下，对于生物反应器中的脱氮起着重要作用。因此，增强AOA的氨氧化能力对水和废水处理具有重要意义，特别是在低溶解氧浓度等条件下。利用本课题组从污水处理厂中提取的新型AOA菌株SAT1，研究了磁场对AOA氨氧化能力，趋磁性和遗传的影响。与对照实验相比，在20 mT磁场下，AOA在培养过程中的最大亚硝酸盐N生成速率增加了56.8％（0.65 mgN /（L $ d））。另外，还证明了AOA具有一定的趋磁性。然而，结果表明，AOA氨氧化能力的增强是不可遗传的，也就是说，一旦去除磁场，其损失就消失了。另外，通过磁场改善AOA氨氧化能力的可能机制是由于AOA单细胞的生长和裂变的促进，而不是其氨氧化速率的提高。研究结果揭示了AOA的应用和增强AOA氨氧化能力的方法，特别是在某些条件下的废水处理过程中。而不是提高其氨氧化速率。研究结果揭示了AOA的应用和增强AOA氨氧化能力的方法，特别是在某些条件下的废水处理过程中。而不是提高其氨氧化速率。研究结果揭示了AOA的应用和增强AOA氨氧化能力的方法，特别是在某些条件下的废水处理过程中。