Discharged sewage is the dominant source of urban river pollution. Macrolide antibiotics have emerged as prominent contaminants, which are frequently detected in sewage and rivers and pose a threat to aquatic microbial community. As a typical primary producer, periphyton is crucial for maintaining the biodiversity and functions of aquatic ecosystem. However, effects of antibiotic exposure time as well as the recovery process of periphyton remain undetermined. In the present study, five exposure scenarios of two typical macrolides, erythromycin (ERY) and roxithromycin (ROX) were investigated at 50 µg/L, dose to evaluate their potential detrimental effects on the structure and function of periphyton and the subsequent recovery process in 14 days. Results revealed that the composition of periphytic community returned to normal over the recovery period, except for a few sensitive species. The antibiotics-caused significant photodamage to photosystem II, leading to continuous inhibition of the photosynthetic capacity of periphyton. Furthermore, no significant difference in carbon metabolism capacity was observed after direct antibiotic exposure, while the amine carbon utilization capacity of periphyton remarkably increased during the recovery process. These results indicated that periphyton community was capable of coping with the periodic exposure of antibiotic pollutants and recovering on its own. However, the ecological functions of periphyton can be permanently disturbed due to macrolide exposure. Overall, this study sheds light on the influence of macrolide exposure on the development, structure and function of the periphytic microbial community in rivers.

中文翻译：

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大环内酯类抗生素的暴露时间是否会影响河流附生生物的发育？深入了解结构和功能


污水排放是城市河流污染的主要来源。大环内酯类抗生素已成为主要污染物，经常在污水和河流中检测到，对水生微生物群落构成威胁。附生植物作为典型的初级生产者，对于维持水生生态系统的生物多样性和功能至关重要。然而，抗生素暴露时间的影响以及附生生物的恢复过程仍不确定。在本研究中，研究了两种典型大环内酯类药物红霉素（ERY）和罗红霉素（ROX）在50 µg/L剂量下的五种暴露场景，以评估它们对附生生物的结构和功能以及随后的恢复过程的潜在有害影响。 14天。结果表明，恢复期内，除少数敏感物种外，附生群落组成已恢复正常。抗生素对光系统II造成显着的光损伤，导致附生生物的光合能力持续受到抑制。此外，直接接触抗生素后碳代谢能力没有观察到显着差异，而恢复过程中附生生物的胺碳利用能力显着增加。这些结果表明附生生物群落能够应对抗生素污染物的周期性暴露并自行恢复。然而，由于大环内酯暴露，附生植物的生态功能可能会受到永久性干扰。总体而言，本研究揭示了大环内酯暴露对河流附生微生物群落的发育、结构和功能的影响。