微塑料对牟氏角毛藻的毒理效应

本文选取聚对苯二甲酸乙二酯（PET）和聚苯乙烯（PS）微粒作为目标污染物，探讨其不同浓度（50 mg/L、100 mg/L和200 mg/L）和不同粒径（100 μm、175 μm和250 μm）对受试生物牟氏角毛藻（Chaetoceros muelleri）的影响。结果表明，3种粒径和浓度的微塑料（PET 和 PS ）均对微藻细胞密度产生抑制作用，PET（100 μm，200 mg/L）和PS（100 μm，200 mg/L）对微藻产生的最大抑制率分别为 37.3% 和 32.5%。微塑料浓度越大，对藻细胞密度的抑制作用越强；而粒径变化对藻细胞密度的抑制作用未呈现明显规律。PET对牟氏角毛藻细胞干重的影响较小，与对照组相比无显著性差异（P>0.05），PS则对牟氏角毛藻细胞干重无影响。微塑料对牟氏角毛藻叶绿素a（Chl a）的抑制作用与其类型和暴露时间有关。PET对Chl a起抑制作用，PS则起促进作用。

Toxicological effects of microplastics on Chaetoceros muelleri

In this study, micro-sized particles polyethylene terephthalate (PET) and polystyrene (PS) were selected as the targeted pollutants, and the effects of PET and PS at different concentrations (50 mg/L, 100 mg/L and 200 mg/L) and particle size (100 μm, 175 μm and 250 μm) on the growth of microalgae Chaetoceros muelleri were investigated. The results showed that three particle sizes and concentrations of microplastics (PET and PS) all had inhibitory effects on the cell density of microalgae. The maximum growth inhibition ratio (IR) reached up to 37.3% and 32.5%, respectively, when the microplastics are at the concentration of 200 mg/L and the size of 100 μm. The inhibitory effect of microplastics to C. muelleri increased with the concentration of PET and PS, but no obvious effect caused by the particle size. As compared with the control group, PET slightly inhibited (P>0.05) the dry cell weight of C. muelleri, while PS had no inhibition on the cells. The inhibitory effect of microplastics on chlorophyll a (Chl a) is related to the type of microplastic and the length of exposure time. The PET inhibited while PS promoted the Chl a content of C. muelleri under the investigated conditions.s on chlorophyll a (Chl a) is related to the type of microplastic and the length of exposure time. The PET inhibited while PS promoted the Chl a content of C. muelleri under the investigated conditions.