Ocean pollution by microplastics represents a threat to phytoplankton health, yet there is few knowledge on physical interactions between microplastics and microalgal cell surfaces. We studied the contact between environmentally aged microplastics and four microalgal species by atomic force microscopy. After seven days, microalgae showed malformations at specific sites, and these malformations varied with species. Depending on whether the cell had a porous or a smooth surface, microplastics adsorbed to the cell surface via embedding or denting, leading to minor defects or noticeable wrinkles in cell walls. Results also showed that microplastics penetrate into microalgae. Such cellular engulfment of microplastics was less present in typical diatoms because diatoms bear a porous frustule capable of trapping tiny particles. Moreover, we observed a novel type of deformation, bowl-shaped depressions, only in non-porous microalgae. The geometric features of malformations are correlated with the shape and size of microplastics. Our findings reveal for the first time the species-specific deformation in microalgae due to microplastic exposure.

微塑料造成的海洋污染对浮游植物的健康构成威胁，但人们对微塑料和微藻细胞表面之间的物理相互作用知之甚少。我们通过原子力显微镜研究了环境老化的微塑料与四种微藻物种之间的接触。 7天后，微藻在特定部位出现畸形，这些畸形因物种而异。根据细胞表面是多孔还是光滑，微塑料通过嵌入或凹陷吸附到细胞表面，导致细胞壁出现微小缺陷或明显皱纹。结果还表明，微塑料会渗透到微藻中。这种对微塑料的细胞吞噬在典型的硅藻中较少出现，因为硅藻具有​​能够捕获微小颗粒的多孔硅藻壳。此外，我们观察到一种新型的变形，即碗状凹陷，仅在无孔微藻中存在。畸形的几何特征与微塑料的形状和大小相关。我们的研究结果首次揭示了由于微塑料暴露而导致的微藻物种特异性变形。