摘要

       作为限制抗生素耐药性传播的潜在手段，废水处理过程越来越受到关注。本研究检查了编码对磺胺（sulI、sulII）、红霉素（erm(B)、erm(F)）和四环素（tet(O)、tet(W)、 tet(C)、tet(G)、tet(X)) 到各种实验室规模的污泥消化过程。 I 类整合子基因 (intI1) 也作为水平基因转移潜力和多重抗生素抗性的指标进行监测。中温厌氧消化在 10 天和 20 天的固体保留时间 (SRT) 显着减少了 sulI、suII、tet(C)、tet(G) 和 tet(X)，更长的 SRT 显示出更大程度的去除；然而，tet(W)、erm(B) 和 erm(F) 基因相对于饲料增加。在 47 °C、52 °C 和 59 °C 下运行的嗜热厌氧消化器的性能彼此相似，并且与 erm(B)、erm(F)、tet(O) 和 tet(W) 相比，它们更有效地减少了中温消化。然而，嗜热消化导致对所有其他 ARG 和 intI1 的去除相似或较差。热水解预处理大大减少了所有 ARG，但它们通常在随后的厌氧和好氧消化处理中反弹。为了深入了解驱动消化器中 ARG 行为的潜在机制，通过变性梯度凝胶电泳比较了优势细菌群落。总体结果表明，污泥消化过程的细菌群落组成，受物理操作特性的控制，比流入的 ARG 组成更能驱动产生的生物固体中存在的 ARG 的分布。

       Wastewater treatment processes are of growing interest as a potential means to limit the dissemination of antibiotic resistance. This study examines the response of nine representative antibiotic resistance genes (ARGs) encoding resistance to sulfonamide (sulI, sulII), erythromycin (erm(B), erm(F)), and tetracycline (tet(O), tet(W), tet(C), tet(G), tet(X)) to various laboratory-scale sludge digestion processes. The class I integron gene (intI1) was also monitored as an indicator of horizontal gene transfer potential and multiple antibiotic resistance. Mesophilic anaerobic digestion at both 10 and 20 day solids retention times (SRTs) significantly reduced sulI, suII, tet(C), tet(G), and tet(X) with longer SRT exhibiting a greater extent of removal; however, tet(W), erm(B) and erm(F) genes increased relative to the feed. Thermophilic anaerobic digesters operating at 47 °C, 52 °C, and 59 °C performed similarly to each other and provided more effective reduction of erm(B), erm(F), tet(O), and tet(W) compared to mesophilic digestion. However, thermophilic digestion resulted in similar or poorer removal of all other ARGs and intI1. Thermal hydrolysis pretreatment drastically reduced all ARGs, but they generally rebounded during subsequent anaerobic and aerobic digestion treatments. To gain insight into potential mechanisms driving ARG behavior in the digesters, the dominant bacterial communities were compared by denaturing gradient gel electrophoresis. The overall results suggest that bacterial community composition of the sludge digestion process, as controlled by the physical operating characteristics, drives the distribution of ARGs present in the produced biosolids, more so than the influent ARG composition.

https://pubs.acs.org/doi/abs/10.1021/es200827t