摘要
      活性污泥中的微生物群落可能会受到抗生素污染的影响。然而，尚不清楚历史上的抗生素应激是如何通过在活性污泥上留下印记来反馈微生物和抗生素抗性基因（ARGs）对联合抗生素应激的后期反应的（“遗留效应”）。为了概念化抗生素遗留效应的作用，选择磺胺甲恶唑（SMX）或甲氧苄啶（TMP）作为历史应激，以研究活性污泥对SMX和TMP联合应激（0.005–30 mg/L）的反应。氨的去除受到输送的活性污泥的影响，活性污泥随着历史抗生素浓度的增加而增加，但受抗生素类型应激的影响较小。在SMX和TMP联合胁迫下，可溶性微生物产物（SMP）和紧密结合的胞外聚合物（TB-EPS）中芳香蛋白样物质和可溶性微生物副产物的变化更为明显，这可以反映微生物对抗生素胁迫的动态反应。遗留效应影响微生物群落的结构和组成对后期抗生素应激的反应。ARGs可以对抗生素胁迫下宿主相对丰度的增加产生正反馈，以占据相对丰度高的细菌的生态位，尤其是比例低但携带多种ARGs（mdtD、mdtG、acrD）的属（Taibaiella、Hydrogenophaga等）。总的来说，输送的活性污泥能够改变其对抗生素应激的反应，ARGs的出现可以推动其潜在宿主的富集。
Abstract
The microbial communities of activated sludge could be affected by antibiotics pollution. However, it is unclear that how the historical antibiotic stress feedback to the later responses of microbes and antibiotic resistance genes (ARGs) to combined antibiotics stress by leaving their imprint on activated sludge (“legacy effect”). In order to conceptualize the role of antibiotic legacy effects, sulfamethoxazole (SMX) or trimethoprim (TMP) was selected as historical stress to investigate responses of activated sludge to combined SMX and TMP stress (0.005–30 mg/L). Ammonia removal was affected by legacy of activated sludge delivered, which increased with the increase of historical antibiotic concentrations, but it was less affected by the legacy of antibiotic type stress. Changes of aromatic protein-like substances and soluble microbial by-products in soluble microbial product (SMP) and tightly bound extracellular polymeric substances (TB-EPS) were more obvious under combined SMX and TMP stress, which could reflect the dynamic response of microorganisms to antibiotics stress. Legacy effects affected response of structure and composition of microbial community to later antibiotic stress. ARGs could produce positive feedback on the increase of relative abundance of hosts under antibiotics stress to occupy the niche of bacteria with high relative abundance, especially genera (Taibaiella, Hydrogenophaga, et al.) with low proportion but carrying multiple ARGs (mdtD, mdtG, acrD). Overall, legacy of activated sludge delivered is able to change its responses to antibiotics stress, and the occurrence of ARGs can drive enrichment of their potential hosts.

https://www.sciencedirect.com/science/article/abs/pii/S2214714422008765