Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education (MOE), College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China; Tianjin Key Laboratory of Urban Ecology Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China.
Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education (MOE), College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China; Tianjin Key Laboratory of Urban Ecology Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China.
Sci Total Environ. 2023 May 20;874:162496. doi: 10.1016/j.scitotenv.2023.162496. Epub 2023 Feb 28.
Despite the increasing research on the fate of nanoplastics (NPs, <100 nm) in freshwater systems, little is known about the joint toxic effects of metal(loid)s and NPs modified with different functional groups on microalgae. Here, we explored the joint toxic effects of two types of polystyrene NPs [one modified with a sulfonic acid group (PSNPs-SOH), and one without this functional group (PSNPs)] and arsenic (As) on the microalgae Microcystis aeruginosa. The results highlighted that PSNPs-SOH showed a smaller hydrodynamic diameter and greater potential to adsorb positively charged ions than PSNPs, contributing to the more severe growth inhibition, while both of them produced oxidative stress. Metabolomics further revealed that the fatty acid metabolism of the microalgae was significantly up-regulated under both NPs exposure, while PSNPs-SOH down-regulated the tricarboxylic acid cycle (TCA cycle) of the microalgae. As uptake by algae was significantly reduced by 82.58 % and 59.65 % in the presence of 100 mg/L PSNPs and PSNPs-SOH, respectively. The independent action model showed that the joint toxicity of both NPs with As was assessed as antagonistic. In addition, PSNPs and PSNPs-SOH had dissimilar effects on the composition of the microalgae extracellular polymeric substances (EPS), resulting in different uptake and adsorption of As, thereby affecting the physiology and biochemistry of algae. Overall, our findings propose that the specific properties of NPs should be considered in future environmental risk assessments.
尽管人们对纳米塑料（NPs，<100nm）在淡水系统中的命运进行了越来越多的研究，但对于不同官能团修饰的纳米塑料和金属（类）联合作用对微藻的毒性效应知之甚少。在这里，我们研究了两种聚苯乙烯纳米颗粒[一种带磺酸基团（PSNPs-SOH），另一种不带此官能团（PSNPs）]和砷（As）对铜绿微囊藻的联合毒性效应。结果表明，PSNPs-SOH 具有更小的水动力直径和更大的吸附正离子的潜力，导致更严重的生长抑制，而两者都产生了氧化应激。代谢组学进一步揭示了在两种 NPs 暴露下，微藻的脂肪酸代谢都显著上调，而 PSNPs-SOH 则下调了微藻的三羧酸循环（TCA 循环）。由于藻类对 As 的摄取分别被 100mg/L PSNPs 和 PSNPs-SOH 显著降低了 82.58%和 59.65%。独立作用模型表明，两种 NPs 与 As 的联合毒性被评估为拮抗作用。此外，PSNPs 和 PSNPs-SOH 对微藻胞外聚合物物质（EPS）的组成有不同的影响，导致 As 的不同吸收和吸附，从而影响藻类的生理和生化特性。总之，我们的研究结果表明，在未来的环境风险评估中，应考虑 NPs 的特定性质。
