Nitrite-dependent anaerobic methane oxidation (N-DAMO) is a newly discovered bioprocess which uses methane as electron donor to reduce nitrite into dinitrogen. It is a promising clean bioprocess for denitrification in wastewater treatment. However, the low reaction rate and slow growth rate of N-DAMO bacteria within NC10 phylum limit the application of the process. In this study, we chose vitamin, heme, nucleobase and betaine to investigate their short- and long-term effects on N-DAMO bacteria. The concentrations of the growth factors of medium were improved according to the short-term experiments. The results were subsequently verified via long-term inoculations and were applied in a magnetically stirred gas lift reactor (MSGLR). The results indicated that nucleobase and betaine (5.0 and 200 μg L⁻¹, respectively) significantly stimulated the N-DAMO activity, whereas vitamin and heme had no significant effects in the tested concentration ranges. During the long-term incubation, N-DAMO bacteria continuously increased and finally achieved a relative abundance of 14.4% on day 300. Notably, larger aggregates of N-DAMO bacteria were observed at the end of the long-term incubation. And the nitrogen removal rate of the MSGLR increased to 70 mg N L⁻¹ day⁻¹, with the total nitrogen removal efficiency over 99.0%. However, the addition of betaine introduced methyl into the reactors and this made methylotrophs account a considerable part of the bacterial community, which limited the enrichment degree of N-DAMO bacteria. This work will contribute to the engineering application and enrichment of N-DAMO bacteria.

亚硝酸盐依赖性厌氧甲烷氧化（N-DAMO）是一个新发现的生物过程，利用甲烷作为电子供体将亚硝酸盐还原为二氮。这是用于废水处理中反硝化的有前途的清洁生物工艺。然而，NC10门内N-DAMO细菌的低反应速率和缓慢的生长速率限制了该方法的应用。在这项研究中，我们选择了维生素，血红素，核碱基和甜菜碱来研究它们对N-DAMO细菌的短期和长期影响。根据短期实验，提高了培养基中生长因子的浓度。随后通过长期接种对结果进行了验证，并将其应用于磁力搅拌气举反应器（MSGLR）。结果表明核碱基和甜菜碱（5.0和200μgL ^-1分别）显着刺激了N-DAMO活性，而维生素和血红素在测试浓度范围内没有显着影响。在长期孵育期间，N-DAMO细菌不断增加，并最终在第300天达到相对丰度14.4％。值得注意的是，在长期孵育结束时，观察到较大的N-DAMO细菌聚集体。MSGLR的脱氮率增加到70 mg NL ^-1 day ^-1，总脱氮效率超过99.0％。然而，甜菜碱的添加将甲基引入反应器中，这使得甲基营养菌占细菌群落的相当大的一部分，这限制了N-DAMO细菌的富集度。这项工作将有助于N-DAMO细菌的工程应用和富集。