Dissimilatory nitrate reduction to ammonium (DNRA) has garnered attention due to its ability to recover ammonia and reduce greenhouse gas emissions simultaneously. In this study, the potential of using static magnetic field (SMF) to improve DNRA process was explored from the sight of molecular biology. Functional genes, microbial community structure, and metabolism pathways were discussed. SMF of 40 mT shortened the start-up time of DNRA from 75 days to 41 days, while 80 mT SMF delayed it to 103 days. On day 80, DNRA potential rate under 40 mT SMF, reached 174 ± 11 μmol kg⁻¹ h⁻¹, significantly surpassing 0 mT (88 ± 6 μmol kg⁻¹ h⁻¹) and 80 mT SMF (52 ± 4 μmol kg⁻¹ h⁻¹). SMF of 40 mT also accelerated community succession and the enrichment of functional bacteria like Geobacter (from 15.71% to 32.11%). qPCR results suggested that 40 mT SMF promoted the rapid enrichment of DNRA functional gene nrfA and 80 mT SMF promoted the enrichment of nirS gene on day 40. Dynamic responses of Thauera sp. RT1901, Stutzerimonas stutzeri, Shewanella oneidensis MR-1, and Shewanella loihica PV-4 to SMF at transcriptional levels confirmed SMF could improve the nitrogen removal and electron transfer of DNRA and denitrification bacteria. Consequently, this work validated the possibility of using SMF to improve DNRA process for ammonia recovery and investigated the underlying mechanisms, which could promote the application of DNRA in full-scale.

硝酸盐异化还原铵（DNRA）因其能够回收氨并同时减少温室气体排放而受到关注。本研究从分子生物学的角度探讨了利用静磁场（SMF）改善DNRA过程的潜力。讨论了功能基因、微生物群落结构和代谢途径。 40 mT SMF 将 DNRA 的启动时间从 75 天缩短至 41 天，而 80 mT SMF 将其延迟至 103 天。第80天，40 mT SMF下的DNRA电位率达到174 ± 11 μmol kg ⁻¹ h ⁻¹ ，显着超过0 mT（88 ± 6 μmol kg ^{−1 1} ) 和 80 mT SMF (52 ± 4 µmol kg ⁻¹ h ⁻¹ )。 40 mT 的 SMF 还加速了群落演替和地杆菌等功能细菌的富集（从 15.71% 增加到 32.11%）。 qPCR结果表明，40 mT SMF促进DNRA功能基因nrfA的快速富集，80 mT SMF促进nirS基因在第40天的富集。 RT1901、Stutzerimonas Stutzeri、Shewanella oneidensis MR-1 和 Shewanella loihica PV-4 在转录水平上转入 SMF，证实 SMF 可以改善 DNRA 和反硝化细菌的脱氮和电子转移。因此，本工作验证了使用SMF改进DNRA氨回收工艺的可能性，并研究了其潜在机制，这可以促进DNRA的全面应用。