To improve poor nitrate removal by microorganisms under strong alkaline conditions, a new type of aerobic nitrification-reducing bacteria was isolated in this study. Using nitrogen balance and genome information, the capacity of Pseudomonas XS-18 to remove nitrate and the mechanism of alkali tolerance were analyzed. At pH 11.0, XS-18 could remove 12.17 mg N/(L·h) nitrate. At C/N ratios of 13.0 and 25 °C, nitrite and ammonia nitrogen were barely enriched. XS-18 could reduce nitrate through dissimilation and assimilation, and 21.74% and 77.39% of nitrate was converted into cellular components and organic nitrogen, respectively. Meanwhile, functional genes (nirBD, nasAB, gdhA, glnA, and gltBD) associated with nitrogen metabolism were determined. In addition, Na⁺/H⁺ antiporters (MnhACDEFG, PhaACDEFG, NhaCD and TrkAH) and a cell surface protein (SlpA) from the XS-18 genome, as well as compatible solutes that help stabilize intracellular pH, were also characterized. XS-18 possessed significant potential in alkaline wastewater treatment.

为改善强碱性条件下微生物对硝酸盐的去除效果不佳，本研究分离出一种新型好氧硝化还原菌。利用氮平衡和基因组信息，分析了假单胞菌XS-18去除硝酸盐的能力和耐碱机制。在 pH 值 11.0 时，XS-18 可以去除 12.17 mg N/(L·h) 硝酸盐。在 C/N 比为 13.0 和 25 °C 时，亚硝酸盐和氨氮几乎没有富集。XS-18可以通过异化和同化作用减少硝酸盐，分别有21.74%和77.39%的硝酸盐转化为细胞成分和有机氮。同时，功能基因（nir BD、nas AB、gdh A、gln A 和gltBD) 与氮代谢相关。此外，来自 XS-18 基因组的Na ⁺ /H ⁺逆向转运蛋白（Mnh ACDEFG、Pha ACDEFG、Nha CD 和Trk AH）和细胞表面蛋白（Slp A），以及有助于稳定细胞内 pH 值的相容溶质，也有特点。XS-18 在碱性废水处理方面具有巨大的潜力。