Zhang Siyu, Wang Hao, Liu Miaomiao, Yu Hongwei, Peng Jianfeng, Cao Xiaofeng, Wang Chunrong, Liu Ruiping, Kamali Mohammadreza, Qu Jiuhui
Center for Water and Ecology, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
School of Chemical and Environmental Engineering, China University of Mining and Technology (Beijing), Beijing 100083, China.
Water Res. 2022 Nov 1;226:119248. doi: 10.1016/j.watres.2022.119248. Epub 2022 Oct 14.
Microplastics (MPs) can adsorb antibiotics to form complex pollutants, which seriously threatens the health of freshwater ecosystems. Few studies have examined the combined pollution characteristics of microplastics (MPs) and antibiotics in restored freshwater ecosystems and their effects on the growth traits of the aquatic primary producers. We studied both the ecotoxicological effects of polyethylene (PE) MPs and the antibiotics sulfanilamide (sulfa, SA) on the structural (diversity etc.,) and functional (nutrient cycling etc.,) properties of water-plant-sediment ecosystems. The synergistic toxic effects of PE and SA resulted in a reduction in the chlorophyll content and chloroplast fluorescence. Meanwhile, PE and SA single/combined pollution stress inhibits the radial oxygen loss in roots, and activates the antioxidant defense system in leaves. The change in the growth response characteristics of Vallisneria natans (V. natans) under oxidative stress induced by single/combined pollution showed a dosage effect. The microbial compositions of the overlying water and sediment were significantly changed by the pollution exposure, as evidenced by the increased microbial diversity and altered microbial taxa distribution. An increase in the total concentrations of sulfa in the overlying water was accompanied by an increase in the relative abundances of resistance genes. PE-MPs significantly affected the removal of total nitrogen and antibiotics from the overlying water. The interaction between PE and SA affects ammonia and nitrite nitrogen exchange in water-sediment systems. Thus, this study investigated the effects of combined MP and antibiotics pollution on the growth state, metabolic function, microbial community structure and microbial diversity of the freshwater ecosystems. The mechanism underlying of the combined polyethylene-sulfanilamide (PE-SA) effect on the V. natans was revealed. In addition, the correlation between different environmental factors was analyzed, and a structural equation model was constructed. This study provides primary data for evaluating the ecological and environmental effects of combined PE-SA pollution and its possible risks. Moreover, it provides a reference index for the study of ecological wetland environments and phytoremediation.
微塑料（MPs）能够吸附抗生素形成复合污染物，这严重威胁着淡水生态系统的健康。很少有研究考察修复后的淡水生态系统中微塑料（MPs）与抗生素的复合污染特征及其对水生初级生产者生长特性的影响。我们研究了聚乙烯（PE）微塑料和抗生素磺胺对水生植物-沉积物生态系统的结构（多样性等）和功能（养分循环等）特性的生态毒理效应。PE和SA的协同毒性作用导致叶绿素含量和叶绿体荧光降低。同时，PE和SA单一/复合污染胁迫抑制根系径向氧损失，并激活叶片中的抗氧化防御系统。单一/复合污染诱导的氧化应激下苦草（Vallisneria natans）生长响应特征的变化呈现剂量效应。污染暴露显著改变了上覆水和沉积物的微生物组成，表现为微生物多样性增加和微生物类群分布改变。上覆水中磺胺总浓度的增加伴随着抗性基因相对丰度的增加。PE-MPs显著影响上覆水中总氮和抗生素的去除。PE和SA之间的相互作用影响水-沉积物系统中的氨和亚硝酸盐氮交换。因此，本研究考察了微塑料与抗生素复合污染对淡水生态系统生长状态、代谢功能、微生物群落结构和微生物多样性的影响。揭示了聚乙烯-磺胺（PE-SA）复合作用对苦草的潜在机制。此外，分析了不同环境因素之间的相关性，并构建了结构方程模型。本研究为评估PE-SA复合污染的生态环境效应及其潜在风险提供了基础数据。此外，它为生态湿地环境和植物修复研究提供了参考指标。
