摘要
      废活性污泥（WAS）是抗生素抗性基因（ARGs）的重要库。然而，WAS中共存物质对ARGs命运的相互作用尚未公开。本研究证明了表面活性剂（用于WAS处理的潜在有效化学品）对WAS发酵过程中ARGs还原的类型依赖性影响，其顺序为线性烷基苯磺酸钠（LAS）>烷基聚葡糖苷（APG）>十六烷基三甲基溴化铵（HTAB）。有趣的是，在表面活性剂处理的反应器中，与外排泵相关的ARGs的比例呈上升趋势。机理研究表明，表面活性剂诱导的胞外聚合物（EPS）破坏增加了细菌细胞的通透性，并导致ARGs被释放，并易于随后被消除。此外，表面活性剂显著改变了微生物群落，通过改变潜在宿主导致ARGs减少。此外，参与ARGs传播的代谢途径被显著下调，从而导致ARGs丰度降低。这项工作拓宽了对WAS发酵过程中ARGs命运的理解，并为外源化学物质在多种基质中的相互作用提供了见解。
Abstract
Waste activated sludge (WAS) is an important reservoir of antibiotic resistance genes (ARGs). However, the interactive effects of co-existed substances in WAS on ARGs fates have yet to be disclosed. This study demonstrated the type-dependent effects of surfactants (potentially effective chemicals for WAS disposal) on the reduction of ARGs during WAS fermentation, which followed the order of linear alkylbenzene sulphonates (LAS) > alkyl polyglucoside (APG) > hexadecyl trimethyl ammonium bromide (HTAB). Interestingly, the ratio of ARGs affiliated to efflux pump showed an upward trend in the surfactant-treated reactor. Mechanistic investigations revealed that the extracellular polymeric substances (EPS) destruction induced by surfactants increased the permeability of bacterial cells and caused the ARGs being released and susceptible for subsequent elimination. Besides, the surfactants significantly altered the microbial community, resulting in the ARGs reduction via changing the potential hosts. Also, the metabolic pathways participated in the dissemination of ARGs were remarkably down-regulated, thereby resulting in the reduction of ARGs abundances. This work broadened the understanding of ARGs fates during WAS fermentation and provided insights on the interactive functions of exogenous chemicals in multiple matrics.

https://www.sciencedirect.com/science/article/abs/pii/S0048969721059003