摘要

在污水处理厂（WWTPs）的生物处理过程中，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，以研究磺胺抗性基因（sulI，sulII）和细菌群落对不同浓度磺胺甲恶唑（SMX）和废水化学需氧量（COD）的响应。 SMX浓度（0.001 mg / L，0.1 mg / L和10 mg / L）随着处理时间的延长而降低，而浓度更高的SMX则更难以去除。 SMX的存在也显着降低了氨氮的去除效率，影响了污水处理厂的正常运行。三种浓度的SMX均提高了sulI和sulII基因，浓度越高，表达量越大。Sul I和sul II基因的丰度与处理时间呈正相关，并遵循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基因丰度也对COD表现出相似的响应。 Simpson指数和Shannon-Weiner指数并未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时期存在差异。结果表明，进入污水处理厂的抗生素可能促进ARG的选择，影响废水的常规处理以及细菌群落结构。

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.

https://www.sciencedirect.com/science/article/pii/S0045653517301534