Polyvinyl chloride (PVC) microplastics present in sewage were trapped in sludge, thereby hindering anaerobic digestion performance of waste active sludge (WAS). Phages regulate virocell metabolism by encoding auxiliary metabolic genes (AMGs) related to energy acquisition and material degradation, supporting hosts survive in harsh environments and play a crucial role in biogeochemical cycles. This study investigated the potential effects of phages on the recovery of WAS anaerobic digestion under PVC stress. We observed a significant alteration in the phage community induced by PVC microplastics. Phages encoded AMGs related to anaerobic digestion and cell growth probably alleviate PVC microplastics inhibition on WAS anaerobic digestion, and 54.2 % of hydrolysis-related GHs and 40.8 % of acidification-related AMGs were actively transcribed in the PVC-exposed group. Additionally, the degradation of chitin and peptidoglycan during hydrolysis and the conversion of glucose to pyruvate during acidification were more susceptible to phages. Prediction of phage-host relationship indicated that the phyla Pseudomonadota were predominantly targeted hosts by hydrolysis-related and acidification-related phages, and PVC toxicity had minimal impact on phage-host interaction. Our findings highlight the importance of phages in anaerobic digestion and provide a novel strategy for using phages in the functional recovery of microplastic-exposed sludge.

中文翻译：

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研究聚氯乙烯微塑性胁迫下噬菌体潜在的辅助厌氧消化活性


污水中存在的聚氯乙烯（PVC）微塑料被截留在污泥中，从而阻碍了废弃活性污泥（WAS）的厌氧消化性能。噬菌体通过编码与能量获取和材料降解相关的辅助代谢基因（AMG）来调节病毒细胞代谢，支持宿主在恶劣环境中生存，并在生物地球化学循环中发挥至关重要的作用。本研究调查了噬菌体对 PVC 胁迫下 WAS 厌氧消化恢复的潜在影响。我们观察到 PVC 微塑料引起的噬菌体群落发生显着变化。噬菌体编码的与厌氧消化和细胞生长相关的AMG可能减轻了PVC微塑料对WAS厌氧消化的抑制，并且在PVC暴露组中，54.2%的水解相关的GH和40.8%的酸化相关的AMG被活跃转录。此外，水解过程中几丁质和肽聚糖的降解以及酸化过程中葡萄糖转化为丙酮酸更容易受到噬菌体的影响。噬菌体-宿主关系的预测表明，假单胞菌门主要是水解相关和酸化相关噬菌体的目标宿主，PVC毒性对噬菌体-宿主相互作用的影响最小。我们的研究结果强调了噬菌体在厌氧消化中的重要性，并为使用噬菌体恢复微塑料暴露污泥的功能提供了一种新策略。