College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, China.
Environmental Microplastic Pollution Research Center, Zhejiang University of Technology, Hangzhou 310014, China.
Molecules. 2023 May 8;28(9):3958. doi: 10.3390/molecules28093958.
The ubiquitous nature of plastics, particularly nanoplastics, raises concern about their potential effects on primary producer microalgae. Currently, the impacts and potential mechanisms of nanoplastics on microalgae are not fully understood. In this study, the effects of two plain commercial polystyrene nanoplastics (PS-NPs) with different sizes (50 nm and 70 nm) on were assessed in a concentration range of 0-50 mg/L during 72 h exposure periods. Results revealed that both PS-NPs have dose-dependent toxicity effects on as confirmed by the decrease of growth rates, chlorophyll a and esterase activities, and the increase of ROS, MDA, and membrane damage. The membrane damage was caused by the agglomeration of PS-NPs on microalgae and may be the key reason for the toxicity. Compared with 70 nm PS-NPs (72 h EC >50 mg/L), 50 nm PS-NPs posed greater adverse effects on algae, with an EC of 19.89 mg/L. FTIR results also proved the stronger variation of macromolecules in the 50 nm PS-NPs treatment group. This phenomenon might be related to the properties of PS-NPs in exposure medium. The lower absolute zeta potential value of 50 nm PS-NPs induced the stronger interaction between PS-NPs and algae as compared to 70 nm PS-NPs, leading to severe membrane damage and the loss of esterase activity as well as settlement. These findings emphasized the importance of considering the impacts of commercial PS-NPs properties in toxicity evaluation.
塑料，尤其是纳米塑料，无处不在，这引起了人们对其对初级生产者微藻潜在影响的关注。目前，纳米塑料对微藻的影响和潜在机制还不完全清楚。在这项研究中，评估了两种普通商业聚苯乙烯纳米塑料（PS-NPs）（粒径分别为 50nm 和 70nm）在 72 小时暴露期内 0-50mg/L 浓度范围内对的影响。结果表明，两种 PS-NPs 对均具有剂量依赖性毒性作用，这可通过生长速率、叶绿素 a 和酯酶活性的降低以及 ROS、MDA 和膜损伤的增加来证实。PS-NPs 在微藻上的团聚导致了膜损伤，这可能是毒性的关键原因。与 70nm PS-NPs（72hEC>50mg/L）相比，50nm PS-NPs 对藻类的不良影响更大，EC 为 19.89mg/L。FTIR 结果也证明了 50nm PS-NPs 处理组中大分子的变化更强。这种现象可能与 PS-NPs 在暴露介质中的性质有关。50nm PS-NPs 的绝对zeta 电位值较低，导致 PS-NPs 与藻类之间的相互作用更强，与 70nm PS-NPs 相比，严重的膜损伤和酯酶活性丧失以及沉降。这些发现强调了在毒性评估中考虑商业 PS-NPs 性质影响的重要性。
