摘要

       抗生素不断释放到水生环境和生态系统中，并在那里积累，这增加了抗生素抗性基因 (ARG) 传播的风险。然而，传统的生物方法很难完全去除抗生素，在这种处理过程中，ARGs可能会通过活性污泥过程传播。据报道，易于生物降解的食物可以改善有毒污染物的去除，因此，本研究调查了此类共底物是否也可能降低 ARG 的丰度及其转移。本研究使用 0–100 mg/L 醋酸钠作为测序生物反应器中的共底物研究了阿莫西林 (AMO) 降解。 Proteobacteria、Bacteroidetes 和 Actinobacteria 被确定为 AMO 去除和矿化的优势门。此外，乙酸盐的添加增加了作为外排抗性基因的 adeF 和 mdsC 的丰度，从而提高了微生物抗性、AMO 毒性的应对能力以及 AMO 损伤的修复。因此，当进水 AMO 从 20 到 100 毫克/升波动时，乙酸盐的添加有助于几乎 100% 的 AMO 去除，并稳定出水中的化学需氧量（~20 毫克/升）。此外，ARGs 的总丰度下降了约 30%，最主要的抗生素抗性细菌 Proteobacteria 的比例下降了约 9%。编码 ARG 的质粒的总丰度减少了约 30%，这意味着 ARG 传播的风险得到了缓解。总之，易于生物降解的食物有助于在活性污泥过程中同时消除抗生素和 ARG。

       Antibiotics are continuously released into aquatic environments and ecosystems where they accumulate, which increases risks from the transmission of antibiotic resistance genes (ARGs). However, it is difficult to completely remove antibiotics by conventional biological methods, and during such treatment, ARGs may spread via the activated sludge process. Easy-to-biodegrade food have been reported to improve the removal of toxic pollutants, and therefore, this study investigated whether such co-substrates may also decrease the abundance of ARGs and their transferal. This study investigated amoxicillin (AMO) degradation using 0–100 mg/L acetate sodium as co-substrate in a sequencing biological reactor. Proteobacteria, Bacteroidetes, and Actinobacteria were identified as dominant phyla for AMO removal and mineralization. Furthermore, acetate addition increased the abundances of adeF and mdsC as efflux resistance genes, which improved microbial resistance, the coping ability of AMO toxicity, and the repair of the damage from AMO. As a result, acetate addition contributed to almost 100% AMO removal and stabilized the chemical oxygen demand (~20 mg/L) in effluents when the influent AMO fluctuated from 20 to 100 mg/L. Moreover, the total abundance of ARGs decreased by approximately ~30%, and the proportion of the most dominant antibiotic resistance bacteria Proteobacteria decreased by ~9%. The total abundance of plasmids that encode ARGs decreased by as much as ~30%, implying that the ARG spreading risks were alleviated. In summary, easy-to-biodegrade food contributed to the simultaneous elimination of antibiotics and ARGs in an activated sludge process.

https://www.sciencedirect.com/science/article/abs/pii/S0048969720364378