环境浓度扑草净存在下聚苯乙烯纳米塑料对隐秘小环藻的毒性效应  

Toxic effects of polystyrene nanoplastics on Cyclotella cryptica in the presence of environmental concentrations of prometryn

作　　者：刘旻昊 张振忠 刘聪 崔旭梦 汝少国[1] 王军[1] LIU Minhao;ZHANG Zhenzhong;LIU Cong;CUI Xumeng;RU Shaoguo;WANG Jun(College of Marine Life Sciences,Ocean University of China,Qingdao 266003,China)

机构地区：[1]中国海洋大学海洋生命学院,山东青岛266003

出　　处：《海洋环境科学》2024年第4期627-636,共10页Marine Environmental Science

基　　金：国家重点研究发展计划项目(2018YFC1407603);中央高校基本科研业务费项目(201964025)。

摘　　要：纳米塑料(nanoplastics,NPs)与除草剂扑草净是海洋环境中的常见污染物,但是它们同时存在对海洋微藻的潜在危害尚不清楚。本文探究了环境浓度扑草净(500 ng/L)与聚苯乙烯纳米塑料(70 nm,20μg/L、200μg/L和2000μg/L)对隐秘小环藻(Cyclotella cryptica)的联合毒性作用。结果表明,20μg/L、200μg/L和2000μg/L NPs能够显著降低隐秘小环藻的光合色素含量、损伤藻细胞结构、抑制隐秘小环藻的种群增长,而500 ng/L扑草净单独暴露并未对隐秘小环藻的早期生长产生显著影响。在500 ng/L扑草净存在下,NPs暴露对隐秘小环藻生长抑制作用会增强,尤其是扑草净与2000μg/L NPs联合暴露24 h后的藻密度比2000μg/L NPs单独暴露组降低了19.4%。环境浓度扑草净的存在还会加重NPs对藻细胞的损伤,使膜通透性增大至对照组的1.6倍。细胞膜受损降低了藻细胞对NPs的抵御能力,从而加重了NPs对隐秘小环藻的毒性作用。与2000μg/L NPs单独暴露组相比,扑草净与2000μg/L NPs联合暴露下的藻细胞在暴露144 h后的死亡率与异形细胞比例分别升高了4.1%和3.4%。本文研究结果可为评估NPs和除草剂污染对海洋初级生产力的危害提供参考。Nanoplastics(NPs)and herbicide prometryn are common pollutants in the marine environments,but their joint impacts on marine microalgae is unclear.In this study,we investigated the toxic effects of environmental concentrations of prometryn(500 ng/L)and polystyrene nanoplastics(70 nm,20,200,and 2000μg/L)on Cyclotella cryptica.The results showed that 20,200 and 2000μg/L NPs significantly reduced photosynthetic pigment content,damaged algal cell structure,and hindered the population growth of C.cryptica.Whereas 500 ng/L prometryn had no significant effect on the early growth of C.cryptica.In the presence of environmental concentrations of prometryn,NPs-induced growth inhibition was significantly enhanced,especially after 24 h of exposure;algal density in the prometryn and 2000μg/L NPs combined exposure groups was reduced by 19.4%compared with that of the 2000μg/L NPs single exposure group.Moreover,the environmental concentrations of prometryn aggravated the damage of NPs to the algal cells,which increased the membrane permeability to 1.6 times that of the control group(P<0.05).Damage to the cell membrane reduced the ability of algal cells to resist the NPs and thus exacerbated the toxicity of NPs to C.cryptica.Compared to the 2000μg/L NPs single exposure,the combined exposure of prometryn and 2000μg/L NPs increased the mortality and proportion of anomalous cells by 4.1%and 3.4%,respectively.The results of this study provide a reference for assessing the hazards of NPs and herbicide pollution on marine primary productivity.

关 键 词：纳米塑料 扑草净 隐秘小环藻 联合暴露 细胞损伤 

分 类 号：X171.5[环境科学与工程—环境科学]