Phenol, quinoline, and pyridine, commonly found in industrial wastewater, disrupt the nitrification process, leading to nitrite accumulation. This study explores the potential mechanisms through which these biotoxic organic compounds affect nitrite accumulation, using metagenomic and molecular docking analyses. Despite increasing concentrations of these compounds from 40 to 160 mg/L, ammonia nitrogen removal was not hindered, and stable nitrite accumulation rates exceeding 90 % were maintained. Additionally, these compounds inhibited nitrite-oxidizing bacteria (NOB) and enriched ammonia-oxidizing bacteria (AOB) in situ. As the concentration of these compounds rose, protein (PN) and polysaccharide (PS) concentrations also increased, along with a higher PN/PS ratio. Metagenomic analysis further revealed an increase in hao relative abundance, while microbial community analysis showed increased Nitrosomonas abundance, which contributed to nitrite accumulation stability. Molecular docking indicated that these compounds have lower binding energy with hydroxylamine oxidoreductase (HAO) and nitrate reductase (NAR), theoretically supporting the observed sustained nitrite accumulation.

中文翻译：

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苯酚、喹啉和吡啶对硝化过程中亚硝酸盐积累的长期影响：性能、微生物群落、宏基因组学和分子对接分析


工业废水中常见的苯酚、喹啉和吡啶会破坏硝化过程，导致亚硝酸盐积累。本研究利用宏基因组和分子对接分析，探讨了这些生物毒性有机化合物影响亚硝酸盐积累的潜在机制。尽管这些化合物的浓度从40 mg/L增加到160 mg/L，但氨氮的去除并未受到阻碍，并且亚硝酸盐累积率保持稳定超过90%。此外，这些化合物还可以原位抑制亚硝酸盐氧化细菌（NOB）并富集氨氧化细菌（AOB）。随着这些化合物浓度的增加，蛋白质 (PN) 和多糖 (PS) 浓度也增加，并且 PN/PS 比率也较高。宏基因组分析进一步揭示了 hao 相对丰度的增加，而微生物群落分析显示亚硝化单胞菌丰度增加，这有助于亚硝酸盐积累的稳定性。分子对接表明这些化合物与羟胺氧化还原酶（HAO）和硝酸盐还原酶（NAR）的结合能较低，从理论上支持了观察到的亚硝酸盐持续积累。