微塑料和紫外线吸收剂对小球藻(Chlorella sp.)的联合毒性效应  

Combined Toxicity of Microplastics and UV Filters on Chlorella sp.in Marine Environment

作　　者：刘锦 秦永强 张彦坤 鞠涵烨 吕炳锐 段丹丹 刁晓平[1,2,3] Liu Jin;Qin Yongqiang;Zhang Yankun;Ju Hanye;Lv Bingrui;Duan Dandan;Diao Xiaoping(Ministry of Education Key Laboratory for Ecology of Tropical Islands,Haikou 571158,China;College of Life Sciences,Hainan Normal University,Haikou 571158,China;State Key Laboratory of Marine Resources Utilization in South China Sea,Hainan University,Haikou 570228,China)

机构地区：[1]热带岛屿生态学教育部重点实验室,海南师范大学,海口571158 [2]海南师范大学生命科学学院,海口571158 [3]南海海洋资源利用国家重点实验室,海南大学,海口570228

出　　处：《生态毒理学报》2024年第4期368-376,共9页Asian Journal of Ecotoxicology

基　　金：海南省重点研发项目(ZDYF2021SHFZ253);海南省自然科学基金面上项目(422MS061);海南省高等学校科学研究重点项目(Hnky2022ZD-5)。

摘　　要：微塑料和紫外线吸收剂作为难降解、持久性强的新型污染物,近年来已成为了国内外环境问题的研究热点。然而,这2类广泛存在于水体中的污染物对海洋微藻的联合毒性仍不明确。本研究添加直径1μm的聚苯乙烯微塑料(polystyrene micro plastics,PS-MPs,10 mg·L^(-1))至不同浓度(50μg·L^(-1)和500μg·L^(-1))的有机紫外线吸收剂阿伏苯宗(butyl methoxydibenzoylmethane,BMDM)海水溶液中,对小球藻(Chlorella sp.)进行7 d的胁迫实验,从生长抑制率、表面形貌和物理特征、光合色素含量、氧化应激水平以及胞外产物(EPS)含量等指标揭示2种污染物对小球藻的联合毒性效应。结果显示:50μg·L^(-1)和500μg·L^(-1)2种浓度的BMDM单一胁迫时,小球藻的最高抑制率分别为26.15%和42.05%,而2种浓度的BMDM与PS-MPs复合胁迫时,小球藻的最高抑制率则分别为15.38%和17.95%,BMDM单一胁迫对小球藻的抑制率高于复合胁迫。原子力显微镜(AFM)对细胞表面的观察发现,与BMDM单一胁迫相比,复合胁迫的小球藻表面凹陷较少,褶皱程度较低。同时,小球藻的表面黏度以及粗糙度均呈现降低的趋势。还原型谷胱甘肽(GSH)含量较低,氧化应激反应减弱。此外,与BMDM单一胁迫相比,复合胁迫的小球藻EPS合成量显著减少,藻胆蛋白(PBPs)的含量较低,而小球藻的细胞密度较高。研究结果表明,PS-MPs和BMDM的联合作用对小球藻的生长表现拮抗效应,即PS-MPs的添加能降低BMDM对小球藻的毒性作用。Microplastics and UV filters,as emerging pollutants that are persistent and difficult to degrade,have raised worldwide concern in recent years.However,their combined toxic effects on marine microalgae are still u nknown.In the present study,a batch of 7-day combined exposure experiments of polystyrene microplastics(PS-MPs,1μm,10 mg·L^(-1))and the organic UV filter butyl methoxydibenzoylmethane(BMDM,50μg·L^(-1)and 500μg·L^(-1))were performed in Chlorella sp.Growth inhibition,surface topography and physical characteristics,photosynthetic pigment content,oxidative stress level,and extracellular polymeric substance(EPS)content of m icroalgae were analyzed.The results showed that the inhibition rates of Chlorella sp.were up to 26.15%and 42.05%under the single BMDM exposures at 50μg·L^(-1)and 500μg·L^(-1),respectively,while they were lower as 15.38%and 17.95%under combined exposures of BMDM and PS-MPs.Atomic force microscopic observation showed less dents and wrinkles on the surface of Chlorella sp.after combined exposures compared to those o bserved after exposure to BMDM alone.The surface viscosity and roughness of Chlorella sp.tended to decrease,along with a decrease in glutathione content and oxidative stress response.In addition,the EPS synthesis in C hlorella sp.was significantly lower in the groups exposed to both pollutants compared to those exposed to B MDM alone,with lower phycobiliproteins content and higher cell density of Chlorella sp.Our study suggests that the addition of PS-MPs could reduce the BMDM toxicity to Chlorella sp.in marine environment.

关 键 词：聚苯乙烯 阿伏苯宗 小球藻 联合毒性 原子力显微镜 

分 类 号：X171.5[环境科学与工程—环境科学]