Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433, PR China.
Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433, PR China.
Chemosphere. 2022 Dec;308(Pt 2):136099. doi: 10.1016/j.chemosphere.2022.136099. Epub 2022 Aug 26.
With the wide application of plastic products, microplastic pollution has become a major environmental issue of global concern. Microplastics in aquatic environments can interact with organic pollutants, causing a combined effect on submerged macrophytes. This study investigated the response mechanisms of the submerged plant Myriophyllum verticillatum and epiphytic biofilm to the antibiotic enrofloxacin, microplastics, and their combined exposure in a high nitrogen and phosphorus environment. The results indicated that Myriophyllum verticillatum was not sensitive to enrofloxacin of 1 mg L, while 10 and 50 mg L enrofloxacin inhibited the uptake of nitrogen and phosphorus by the plants, as well as triggered oxidative stress in the plant leaves, causing irreversible damage to the plant cells. In addition, enrofloxacin altered the structure of the leaf epiphytic biofilm community. Interestingly, 1, 5, and 20 mg L microplastics had no significant effect on the plant, while they facilitated the aggregation of microorganisms, increasing the abundance of the leaf epiphyte biofilm. The combination of enrofloxacin and microplastics induced a synergistic effect on Myriophyllum verticillatum. Specifically, the rate of nitrogen and phosphorus uptake by the plant was reduced, the content of photosynthetic pigments decreased, and antioxidant enzyme activity was further increased. In addition, the diversity of the leaf epiphytic biofilm community was similar to the single enrofloxacin exposure. These results demonstrated the differences between single and combined exposures and provided a new theoretical basis to evaluate the harmful effects of enrofloxacin and microplastics on submerged macrophytes.
随着塑料制品的广泛应用，微塑料污染已成为全球关注的重大环境问题。水生态环境中的微塑料可以与有机污染物相互作用，对沉水植物产生联合效应。本研究以沉水植物穗花狐尾藻和附生生物膜为研究对象，探讨了在高氮磷环境下，抗生素恩诺沙星、微塑料及其复合暴露对其的响应机制。结果表明，穗花狐尾藻对 1mg/L 的恩诺沙星不敏感，而 10 和 50mg/L 的恩诺沙星抑制了植物对氮、磷的吸收，并引发了植物叶片的氧化应激，对植物细胞造成不可逆的损伤。此外，恩诺沙星改变了叶片附生生物膜群落的结构。有趣的是，1、5 和 20mg/L 的微塑料对植物没有显著影响，但促进了微生物的聚集，增加了叶片附生生物膜的丰度。恩诺沙星和微塑料的组合对穗花狐尾藻产生了协同作用。具体而言，植物对氮、磷的吸收速率降低，光合色素含量减少，抗氧化酶活性进一步增加。此外，叶片附生生物膜群落的多样性与单一恩诺沙星暴露相似。这些结果表明了单一和复合暴露之间的差异，为评估恩诺沙星和微塑料对沉水植物的有害影响提供了新的理论依据。
