摘要
      各国政府制定了更严格的污水处理厂排放标准，以解决水污染问题；但是其代价是加重放电的难熔性。这些政策不符合经典的共同代谢理论；因此，我们评估了一种易于生物降解的基质对接收水中抗生素和抗生素抗性基因（ARGs）去除效率的影响。在本研究中，建造了具有8天水力停留时间（HRT）的反应器来模拟接收河流，并将几种抗生素（每种0.30mg/L）连续排放到反应器中（四环素、环丙沙星、阿莫西林、氯霉素和磺胺甲恶唑）。使用乙酸钠（NaAc）作为代表性的易生物降解底物，并比较了有助底物和无助底物的处理方案。分析了抗生素在模拟河流中的衰减以及ARGs的产生和传播。结果显示，50 mg/L的NaAc激活了非特异性酶（与0 mg/L NaAc相比，log2倍的变化为3.1–8.8）。抗生素的去除率提高了4–32%，下游水的毒性降低了35%。抗氧化酶的上调导致细胞内活性氧（ROS）减少了47%，抑制了水平基因转移，并使移动遗传元件介导的ARGs（mARGs）减少了18-56%。此外，NaAc还使微生物群落的α多样性增加了5-15%（Shannon Wiener指数），并使人类细菌病原体的丰度减少了22-36%。总之，接收水中易于生物降解的基质对于降低抗生素风险至关重要。
Abstract
Governments have formulated stricter wastewater treatment plant (WWTP) discharge standards to address water pollution; however, with the cost of aggravating the refractory of the discharges. These policies are not in line with the classic co-metabolism theory; thus, we evaluated the effects of an easily biodegradable substrate on the removal efficiency of antibiotics and antibiotic resistance genes (ARGs) in the receiving water. In this study, reactor with 8 d of hydraulic retention time (HRT) was constructed to simulate a receiving river, and several antibiotics (0.30 mg/L each) were continuously discharged to the reactor (tetracycline, ciprofloxacin, amoxicillin, chloramphenicol, and sulfamethoxazole). Sodium acetate (NaAc) was used as a representative easily biodegradable substrate, and treatment protocols with and without a co-substrate were compared. The attenuation of the antibiotics in the simulated river and the production and dissemination of ARGs were analyzed. The results showed that 50 mg/L NaAc activated non-specific enzymes (a log2-fold change of 3.1–8.8 compared with 0 mg/L NaAc). The removal rate of the antibiotics was increased by 4–32%, and the toxicity of the downstream water was reduced by 35%. The upregulation of antioxidant enzymes caused the intracellular reactive oxygen species (ROSs) decreased by up to 47%, inhibiting horizontal gene transfer and reducing mobile genetic element-mediated ARGs (mARGs) by 18–56%. Furthermore, NaAc also increased the alpha diversity of the microbial community by 5–15% (Shannon-Wiener Index) and reduced the abundance of human bacterial pathogens by 22–36%. In summary, easily biodegradable substrates in the receiving water are crucial for reducing antibiotic risk.

https://www.sciencedirect.com/science/article/abs/pii/S0043135421011660