摘要 

       仍不清楚微塑料（MPs）与周围各种盐度的水之间的抗生素和抗生素抗性基因（ARG）的分配。在这项研究中，我们假设MP上的抗生素吸附可能导致MP上微生物群落结构的改变，ARGs的多样性和丰度的变化，而盐度的变化可能会进一步影响这种变化。在这项研究中，我们研究了四种常见抗生素（磺胺嘧啶，四环素，氯霉素和泰乐菌素）在河流，河口和海水中的聚乙烯MPs上的吸附，以及MPs和在三个水域。结果表明，MPs可以富集周围水中的抗生素，ARG和微生物。盐度升高可减少抗生素对MP的吸附和ARG的丰富。例如，国会议员可以在河水中和河口和海水中集中更多的抗生素和ARG。此外，在四种抗生素的压力下，不同盐度下MPs上的ARG和细菌群落也显着不同。在MP上，sul1，sulA / folP-01，tetA，tetC，tetX和ermE显着增加，但出现了一些新的ARG，例如sulA / folP-01和tetA。 MPs上的细菌群落结构与周围的水不同，因为在MP中发现的一些细菌在周围水中几乎没有被检测到，而MPs上的某些属在暴露于抗生素后消失了。随着水中盐分的吸附，MPs上的抗生素吸附和ARGs减少，因此MPs上的群落结构随盐度的变化而变化。这些发现对于了解MPs在不同水生环境中对抗生素和ARGs的运输，命运和生态风险的影响非常重要。

       The partition of antibiotics and antibiotic resistant genes (ARGs) between the microplastics (MPs) and the surrounding water with various salinity are still unclear. In this study, we hypothesized that adsorption of antibiotics on MPs might cause a significant change of the structure of microbial communities, diversity and abundance of ARGs on MPs and this might be further affected by change of salinity. In this study, we investigated adsorption of four common antibiotics (sulfamerazine, tetracycline, chloramphenicol and tylosin) to polyethylene (PE) MPs in river, estuary and marine waters, and the differences of antibiotic resistant genes (ARGs) and bacterial communities on MPs and in the three waters. The results showed that MPs can enrich antibiotics, ARGs and microbes from the surrounding water. Elevated salinity could reduce adsorption of antibiotics to MPs and the abundance of ARGs. For example, MPs can concentrate more antibiotics and ARGs in the fresh river water than in the estuary and the marine waters. In addition, ARGs and bacterial communities on MPs at various salinity were significantly different under the pressure of four antibiotics. On MPs, sul1, sulA/folP-01, tetA, tetC, tetX and ermE increased significantly but a few new ARGs such as sulA/folP-01 and tetA appeared. The structure of the bacterial communities on MPs was different from the surrounding water since some bacteria species found on MPs were barely detected in the surrounding water while some genera on MPs vanished after exposure to antibiotics. As the antibiotics adsorbed and the ARGs on MPs decreased with the water salinity, the structure of the communities on MPs thus varied with salinity change. These findings are important to understand the effects of MPs on the transport, fate and ecological risk of antibiotics and ARGs in different aquatic environments.

      https://www.sciencedirect.com/science/article/abs/pii/S0048969719345851