摘要
      微塑料（MP）、纳米塑料（NP）和抗生素抗性基因（ARGs）作为新出现的污染物，在污水处理厂中经常被检测到。然而，在生物除磷（BPR）系统中，磷和ARGs在MP和NP（MP/NP）压力下的行为仍然未知。本研究研究了MP/NPs对BPR系统中磷去除和ARGs繁殖的影响。结果表明，MP/NPs对磷的去除没有影响，但显著促进了四环素抗性基因（TRGs）的扩增。此外，MP比NP更促进TRG的丰度，并且主要富集外排泵和酶修饰机制的TRG。同时，MP/NP增加了多种抗性基因和移动基因元件（MGE）的传播风险。微生物群落表明，主要的聚磷酸盐积累生物从不动杆菌转移到了未分类的γ-磷酸盐细菌，这解释了为什么添加MP/NP不影响除磷效率。相关性分析显示，ARGs和MGE之间没有显著的相关性（intI1和intI2），但随着MP/NP的添加，ARG潜在宿主的丰度显著增加，这表明微生物群落结构的变化而不是基因水平转移是MP/NP压力下促进ARG繁殖的主要因素。
Abstract
Microplastics (MPs), nanoplastics (NPs) and antibiotic resistance genes (ARGs), as emerging pollutants, have been frequently detected in wastewater treatment plants. However, the behavior of phosphorus and ARGs under MP and NP (MP/NP) pressure in biological phosphorus removal (BPR) system is still unknown. This study investigated the effects of MP/NPs on phosphorus removal and ARGs propagation in BPR system. Results showed that MP/NPs had no influence on phosphorus removal, but significantly promoted the amplification of tetracycline resistance genes (TRGs). Moreover, the TRG abundance were more facilitated by MPs than NPs, and the TRGs of efflux pump and enzymatic modification mechanism were mainly enriched. Meanwhile, MP/NPs increased the transmission risk of multiple resistance genes and mobile gene elements (MGEs). Microbial communities demonstrated the main polyphosphate accumulating organisms shifted from Acinetobacter to unclassified_Gammaproteobacteria, which explained why phosphorus removal efficiency was unaffected with MP/NP addition. Correlation analysis revealed there was no significant correlation between ARGs and MGEs (intI1 and intI2), but the abundances of potential hosts of ARGs were significantly increased with MP/NP addition, implying microbial community structure changes rather than gene horizontal transfer was the main factor promoting ARG propagation under MP/NP pressure.

https://www.sciencedirect.com/science/article/abs/pii/S0304389422003351