摘要
      抗生素已成为废水中出现的新污染物，影响负责废水处理的微生物的活性。此外，厌氧氨氧化工艺在含抗生素废水处理中的潜在应用也备受关注。作为一种常见的抗生素，OTC（土霉素）、CIP（环丙沙星）和CLA（克拉霉素）由于其相对较高的浓度和对环境的有害影响，被认为是废水中需要监测的抗生素。然而，它们对厌氧氨氧化过程的影响仍然未知。因此，本文研究了连续浓度的三种抗生素（OTC、CIP、CLA）对厌氧氨氧化过程的长期影响，特别强调了处理效率、抗性机制、细菌细胞形态和活性污泥群落结构。值得注意的是，首次研究了CIP和CLA连续浓度的影响。结果表明，厌氧氨氧化菌群落在低浓度（<1 mg L-1）下可以适应CIP、OTC和CLA，而高浓度抗生素（100 mg L-1）使氮去除率（NRR）分别降低了27%（OTC）、30%（CIP）和56%（CLA）。群落结构分析表明，扁霉菌的丰度随着CIP和CLA浓度的增加而增加，而在OTC胁迫下则减少。相反，其他氮循环细菌（如氮螺旋菌）有助于氮的去除，尤其是在抗生素抑制期间。在抗生素抑制下，相应ARGs（OTC抗性基因：tetX、tetC、tetW、CIP抗性基因：qnrB4、qnrS、CLA抗性基因：mphA）的丰度通常增加。此外，共现分析表明厌氧氨氧化菌可能参与了大环内酯类抗性基因的转移。这项研究的发现对于理解厌氧氨氧化过程中废水中常见的三种抗生素的作用机制至关重要。此外，该结果对使用厌氧氨氧化法处理含抗生素废水具有指导意义，并为在抗生素抑制下稳定进行厌氧氨氧化工艺提供了操作指导。
Abstract
Antibiotics have become emerging pollutants occurring in wastewater, influencing the activity of microorganisms responsible for wastewater treatment. Moreover, the potential application of the anammox process in the treatment of antibiotic-containing wastewater has paid much attention. A common antibiotic, OTC (oxytetracycline), CIP (ciprofloxacin), and CLA (clarithromycin) are recognized to be monitored in wastewater due to their relatively high concentration and hazardous impact on the environment. However, their effect on the anammox process remains unknown. Therefore, this paper presents the study concerning the long-term effects of a successive concentration of three antibiotics (OTC, CIP, CLA) on the anammox process, with special emphasis on treatment efficiency, resistance mechanism, bacteria cell morphology, and activated sludge community structure. It is worth noting that the influence of a successive concentration of CIP and CLA has been studied for the first time. Results revealed that anammox community could adapt to CIP, OTC, and CLA at low concentrations (<1 mg L-1), while the high concentration of antibiotics (100 mg L-1) reduced the nitrogen removal rate (NRR) by 27 % (OTC), 30 % (CIP), and 56 % (CLA). Community structure analysis showed that the abundance of Planctomycetes increased with the increase of CIP and CLA concentration while decreasing under OTC stress. On contrary, other nitrogen-cycle bacteria (e.g., Nitrospira) contributed to the nitrogen removal, especially during antibiotic suppression. The abundance of corresponding ARGs (OTC resistance gens: tetX, tetC, tetW, CIP resistance gens: qnrB4, qnrS, CLA resistance gens: mphA) generally increased under antibiotic suppression. In addition, co-occurrence analysis showed that anammox bacteria might participate in the transfer of macrolide resistance genes. The findings of this study are essential in understanding the mechanisms of three antibiotics commonly occurring in wastewater during the anammox process. Moreover, the results have implications for using the anammox process for antibiotic-containing wastewater treatment and provide the operational guidance for stable conducting of the anammox process under antibiotics suppression.

https://www.sciencedirect.com/science/article/abs/pii/S138589472204027X