Key Laboratory of Yangtze River Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
Key Laboratory of Yangtze River Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
Chemosphere. 2017 May;175:21-27. doi: 10.1016/j.chemosphere.2017.01.134. Epub 2017 Feb 1.
The abundant microbial community in biological treatment processes in wastewater treatment plants (WWTPs) may potentially enhance the horizontal gene transfer of antibiotic resistance genes with the presence of antibiotics. A lab-scale sequencing batch reactor was designed to investigate response of sulfonamide resistance genes (sulI, sulII) and bacterial communities to various concentrations of sulfamethoxazole (SMX) and chemical oxygen demand (COD) of wastewater. The SMX concentrations (0.001 mg/L, 0.1 mg/L and 10 mg/L) decreased with treatment time and higher SMX level was more difficult to remove. The presence of SMX also significantly reduced the removal efficiency of ammonia nitrogen, affecting the normal function of WWTPs. All three concentrations of SMX raised both sulI and sulII genes with higher concentrations exhibiting greater increases. The abundance of sul genes was positive correlated with treatment time and followed the second-order reaction kinetic model. Interestingly, these two genes have rather similar activity. SulI and sulII gene abundance also performed similar response to COD. Simpson index and Shannon-Weiner index did not show changes in the microbial community diversity. However, the 16S rRNA gene cloning and sequencing results showed the bacterial community structures varied during different stages. The results demonstrated that influent antibiotics into WWTPs may facilitate selection of ARGs and affect the wastewater conventional treatment as well as the bacteria community structures.
污水处理厂（WWTP）生物处理过程中丰富的微生物群落，在抗生素存在的情况下，可能会增强抗生素抗性基因的水平基因转移。设计了一个实验室规模的序批式反应器，以研究磺胺类抗性基因（sulI、sulII）和细菌群落对不同磺胺甲恶唑（SMX）浓度和废水化学需氧量（COD）的响应。随着处理时间的延长，SMX 浓度（0.001mg/L、0.1mg/L 和 10mg/L）降低，较高的 SMX 水平更难去除。SMX 的存在还显著降低了氨氮的去除效率，影响了 WWTP 的正常功能。三种浓度的 SMX 均提高了 sulI 和 sulII 基因的丰度，较高浓度的基因丰度增加更大。sul 基因的丰度与处理时间呈正相关，符合二级反应动力学模型。有趣的是，这两个基因具有相似的活性。sulI 和 sulII 基因的丰度对 COD 的响应也相似。辛普森指数和香农-威纳指数没有显示微生物群落多样性的变化。然而，16S rRNA 基因克隆和测序结果表明，细菌群落结构在不同阶段发生了变化。结果表明，进入 WWTP 的进水抗生素可能促进了 ARGs 的选择，并影响了废水的常规处理以及细菌群落结构。
