氯代阻燃剂得克隆对纤细裸藻的生态毒性效应

摘要

Dechlorane Plus (DP) is a widely used chlorinated flame retardant and regarded as a persistent organic pollutant (POPs) and an environmental toxin.However,the biological toxicity data of DP is still quite limited.In this study,we investigated its toxic effect on the aquatic Euglena gracilis,which is a sensitive primary producer,by analyzing the growth curves,photosynthetic pigments and activities of several enzymes such as superoxide dismutase (SOD),peroxidase (POD),glutathione (GSH) and malondialdehyde (MDA).Our results showed that low levels of DP could stimulate the growth of E.gracilis,but the effect was not obvious.It was also found that carote-noids were slightly inhibited when exposed to low levels of DP (0.1 and 0.5 mg·L-1 DP).However,high levels of DP (8 mg· L-1) could lead to the accretion of GSH,SOD and POD as well as the rising level of MDA which indicated DP's potential damage of cell membranes.In a world,our results provide scientific basis for the assessment of the overall environmental ecological toxicity of DP.%得克隆(Dechlorane Plus,DP)作为全球广泛使用的氯代阻燃剂,具有POPs特性和环境毒性,但其生物毒性数据非常有限.本文选择水生初级生产者纤细裸藻(Euglena gracilis)作为研究对象,通过检测藻细胞生长状况、光合色素水平、抗氧化酶活性、谷胱甘肽(GSH)和丙二醛(MDA)含量变化,研究了不同浓度DP对其生态毒性效应的影响.结果显示,低浓度DP对纤细裸藻生长具有一定促进作用,但差异不显著;DP浓度较低时(0.1和0.5 mg·L-1DP)类胡萝卜素含量受到轻微抑制;较高浓度DP暴露导致超氧化物歧化酶(SOD)、过氧化物酶(POD)和谷胱甘肽(GSH)水平显著增加,同时高浓度DP(8 mg· L-1)下MDA含量显著上升,提示膜结构受到损伤;表明较高实验浓度范围内,DP对纤细裸藻的生长及抗氧化系统均产生一定影响,结果将为DP的环境生态风险评价提供科学依据.