The inhibitory effects of oxytetracycline (OTC) on the anaerobic ammonium oxidation (anammox) performance were relieved by employing bio-augmentation (BA) tactics. However, the recovery mechanism was vague. The response of specific anammox activity (SAA), heme c, functional genes, extracellular polymeric substance (EPS) and antibiotics resistance genes (ARGs) to OTC inhibition and BA aid were traced in the present study. The results indicated that response of SAA, heme c content and functional genes, such as nirS, hzsA and hdh to OTC inhibition were not synchronous. The presence of the tetC, tetG, tetX, and intI1 genes enhanced the resistance of anammox sludge to OTC, thus accelerating the performance recovery when aided by BA. A significant correlation existed between number of anammox 16S rRNA gene copies and protein level in the soluble microbial products (SMP), between tetG gene relative abundance and polysaccharose in SMP and between tetG gene relative abundance and protein in bound EPS (EPSs). In nutshell, the current findings provide the first description of a recovery mechanism regarding OTC-inhibited anammox performance aided by BA based on functional genes and highlights the contribution of ARGs and the self-resistance ability of EPS.

土霉素（OTC）对厌氧铵氧化（anammox）性能的抑制作用通过采用生物增强（BA）策略得以缓解。但是，恢复机制是模糊的。在本研究中跟踪了特定的厌氧氨氧化活性（SAA），血红素c，功能基因，细胞外聚合物（EPS）和抗生素抗性基因（ARG）对OTC抑制和BA辅助的反应。结果表明SAA，血红素C含量和功能基因，如该响应NIR S，HZS A和HDH到OTC抑制不同步。所述的存在TET C，TET G，TET X和INTI1基因增强了厌氧菌污泥对OTC的抵抗力，从而在BA的辅助下加速了性能恢复。厌氧菌16S rRNA基因拷贝数与可溶性微生物产物（SMP）中的蛋白质水平，tet G基因相对丰度和SMP中的多糖之间以及tet G基因相对丰度与结合EPS（EPS）中的蛋白质之间存在显着相关性。简而言之，当前发现为基于功能基因的BA辅助OTC抑制厌氧氨氧化性能的恢复机制提供了第一个描述，并突出了ARGs的贡献和EPS的自抗性。