摘要
      污水处理厂（WWTP）中的塑性塑料（微塑料上的生物膜）可能会富集病原体和抗生素抗性基因（ARGs），这些病原体和抗生素耐药性基因会排放到接收水中，对生态环境造成风险。然而，活性污泥（AS）系统中的微生物组和质体的抗性仍然没有定论。在此，应用宏基因组研究了实验室规模反应器中聚氯乙烯（PVC）塑料圈的微生物组成、功能和ARGs，并揭示了四环素（TC）和/或铜（II）压力对它们的影响。结果表明，塑料层为微生物群提供了一个新的生态位，显示出不同于AS的独特功能。特别是，各种潜在的致病菌倾向于在PVC塑料层中富集。此外，在质体和AS中检测到各种ARGs，但质体具有更多潜在的ARGs宿主，并且与ARGs的相关性更强。暴露于TC和/或Cu（II）压力后，ARGs的丰度增加，尤其是四环素抗性基因（TRGs），结果进一步表明，具有不同抗性机制的TRGs在质体和AS中分别富集。此外，来自Cu（Ⅱ）或/和TC的外源压力也增强了潜在病原体与PVC质体中TRGs的联系。这些发现有助于评估通过污水处理厂中的微塑料传播病原体和ARGs的潜在风险。
Abstract
Plastisphere (the biofilm on microplastics) in wastewater treatment plants (WWTPs) may enrich pathogens and antibiotic resistance genes (ARGs) which can cause risks to the ecological environment by discharging into receiving waters. However, the microbiome and resistome of plastisphere in activated sludge (AS) systems remain inconclusive. Here, metagenome was applied to investigate the microbial composition, functions and ARGs of the Polyvinyl chloride (PVC) plastisphere in lab-scale reactors, and revealed the effects of tetracycline (TC) and/or Cu(II) pressures on them. The results indicated that the plastisphere provided a new niche for microbiota showing unique functions distinct from the AS. Particularly, various potentially pathogenic bacteria tended to enrich in PVC plastisphere. Moreover, various ARGs were detected in plastisphere and AS, but the plastisphere had more potential ARGs hosts and a stronger correlation with ARGs. The ARGs abundances increased after exposure to TC and/or Cu(II) pressures, especially tetracycline resistance genes (TRGs), and the results further showed that TRGs with different resistance mechanisms were separately enriched in plastisphere and AS. Furthermore, the exogenous pressures from Cu(II) or/and TC also enhanced the association of potential pathogens with TRGs in PVC plastisphere. The findings contribute to assessing the potential risks of spreading pathogens and ARGs through microplastics in WWTPs.

https://www.sciencedirect.com/science/article/abs/pii/S0048969722054298