Annenkov Vadim V, Pal'shin Viktor A, Annenkova Nataliia V, Zelinskiy Stanislav N, Danilovtseva Elena N
Limnological Institute, Siberian Branch of the Russian Academy of Sciences, Irkutsk, Russia.
Environ Toxicol Chem. 2023 May;42(5):1124-1133. doi: 10.1002/etc.5604. Epub 2023 Apr 12.
Plastic nanoparticles (NPs) are the final state of plastic degradation in the environment before they disintegrate into low-molecular-weight organic compounds. Unicellular organisms are highly sensitive to the toxic effects of nanoplastics, because they are often capable of phagotrophy but are unable to consume a foreign material such as synthetic plastic. We studied the effect of polystyrene, poly(vinyl chloride), poly(methyl acrylate), and poly(methyl methacrylate) NPs on the photosynthetic dinoflagellate Gymnodinium corollarium Sundström, Kremp et Daugbjerg. Fluorescent tagged particles were used to visualize plastic capture by dinoflagellate cells. We found that these dinoflagellates are capable of phagotrophic nutrition and thus should be regarded as mixotrophic species. This causes their susceptibility to the toxic effects of plastic NPs. Living cells ingest plastic NPs and accumulate in the cytoplasm as micrometer-level aggregates, probably in food vacuoles. The action of nanoplastics leads to a dose-dependent increase in the level of reactive oxygen species in dinoflagellate cells, indicating plastic degradation in the cells. The introduction of a methyl group into the main chain in the α-position in the case of poly(methyl methacrylate) causes a drastic reduction in toxicity. We expect that such NPs can be a tool for testing unicellular organisms in terms of heterotrophic feeding ability. We suggest a dual role of dinoflagellates in the ecological fate of plastic waste: the involvement of nanoplastics in the food chain and its biochemical destruction. Environ Toxicol Chem 2023;42:1124-1133. © 2023 SETAC.
塑料纳米颗粒（NPs）是塑料在环境中降解的最终状态，之后它们会分解为低分子量有机化合物。单细胞生物对纳米塑料的毒性作用高度敏感，因为它们通常具有吞噬营养能力，但无法消耗诸如合成塑料之类的外来物质。我们研究了聚苯乙烯、聚氯乙烯、聚丙烯酸甲酯和聚甲基丙烯酸甲酯纳米颗粒对光合甲藻科罗拉多裸甲藻（Gymnodinium corollarium Sundström, Kremp et Daugbjerg）的影响。使用荧光标记颗粒来观察甲藻细胞对塑料的捕获情况。我们发现这些甲藻具有吞噬营养能力，因此应被视为混合营养型物种。这导致它们对塑料纳米颗粒的毒性作用敏感。活细胞摄取塑料纳米颗粒并在细胞质中以微米级聚集体的形式积累，可能是在食物泡中。纳米塑料的作用导致甲藻细胞中活性氧水平呈剂量依赖性增加，表明细胞内塑料发生了降解。在聚甲基丙烯酸甲酯的情况下，在主链的α位引入甲基会导致毒性大幅降低。我们预计此类纳米颗粒可作为测试单细胞生物异养摄食能力的工具。我们提出甲藻在塑料废物的生态命运中具有双重作用：纳米塑料参与食物链及其生化破坏。《环境毒理学与化学》2023年；42:1124 - 1133。© 2023 SETAC。
