State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China.
State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China.
J Hazard Mater. 2022 Apr 5;427:127937. doi: 10.1016/j.jhazmat.2021.127937. Epub 2021 Nov 27.
As important emerging contaminants, nanoplastics can act as vectors for other environmental pollutants, resulting in their migration throughout ecosystems and altering their toxicity. In this study, the fluorescent dye label aggravated the toxicity of polystyrene (PS) nanoplastics (100 nm diameter particles) to microalgae Euglena gracilis. Therefore, the toxicity of non-fluorescent labelled PS alone and in combination with divalent cadmium (Cd) on Euglena gracilis in the environmentally relevant concentrations was investigated. Results revealed that co-exposure to 50 μg/L (1.1 × 10 particles/L) PS and 50 μg/L Cd resulted in synergistic effects, significantly inhibiting microalgal growth by 28.76%. Superoxide dismutase, peroxidase and extracellular polymeric substances were distinctly enhanced in co-exposure treatments compared to the control, indicating that cellular antioxidant defense responses were activated. LC-MS-based metabolomic analysis suggested that PS and Cd exposure alone or in combination induced significant disruption to carbohydrate and purine metabolism-related pathways, as compared to controls. As part of the PS and Cd stress response, differential metabolites involved in lipid metabolism and amino acid metabolism provide antioxidants and cell membrane protective molecules. Overall, this combined physiological and metabolomic analysis approach provides a better understanding of the potential risks posed by nanoplastics and heavy metal pollution in aquatic ecosystems.
作为新兴的重要污染物，纳米塑料可以作为其他环境污染物的载体，导致它们在整个生态系统中迁移，并改变它们的毒性。在这项研究中，荧光染料标记加重了聚苯乙烯（PS）纳米塑料（直径 100nm 的颗粒）对绿眼虫的毒性。因此，研究了在环境相关浓度下，非荧光标记的 PS 单独存在以及与二价镉（Cd）共存对绿眼虫的毒性。结果表明，暴露于 50μg/L（1.1×10 个颗粒/L）PS 和 50μg/L Cd 会产生协同作用，使微藻的生长显著抑制 28.76%。与对照组相比，共暴露处理中超氧化物歧化酶、过氧化物酶和细胞外聚合物明显增强，表明细胞抗氧化防御反应被激活。基于 LC-MS 的代谢组学分析表明，与对照组相比，PS 和 Cd 单独或联合暴露会显著破坏碳水化合物和嘌呤代谢相关途径。作为 PS 和 Cd 应激反应的一部分，参与脂质代谢和氨基酸代谢的差异代谢物提供了抗氧化剂和细胞膜保护分子。总的来说，这种结合生理和代谢组学分析的方法可以更好地了解纳米塑料和重金属污染对水生生态系统造成的潜在风险。
