壬基酚在蛋白核小球藻和大型溞体内的富集与传递

为探究壬基酚(nonylphenol,NP)在水生生物中的富集传递效应,选择以蛋白核小球藻(Chlorella pyrenoidosa)和大型溞(Daphnia magna)为研究对象,开展蛋白核小球藻对NP的富集效应实验,及NP在蛋白核小球藻和大型溞体内的传递效应实验。研究结果表明,NP对蛋白核小球藻的96 h半数效应浓度(96 h-EC50)为3.13 mg·L~(-1),对蛋白核小球藻的生长和叶绿素含量的影响呈现明显的剂量-时间效应。NP对大型溞的48 h半数效应浓度(48 h-LC50)为37.41μg·L~(-1),属于高毒类化合物。蛋白核小球藻暴露于0.05 mg·L-1NP 4 h后,其生物富集系数(BCF)为5 144.93,富集量为252.2μg·g~(-1),在12 h内对NP的生物富集系数(BCF)最高达12 053.64,富集量为1 181.73μg·g~(-1)。以0.05 mg·L-1NP中暴露4 h后的蛋白核小球藻为饵料投喂大型溞7 d后,大型溞体内NP富集量最高达3.6μg·g~(-1)。0.05 mg·L~(-1)NP直接暴露组大型溞暴露10 d后,大型溞体内NP富集量最高达4.02μg·g~(-1)。蛋白核小球藻对NP具有较强的富集能力,能够通过摄食过程将NP传递到大型溞,经传递的NP能够显著抑制大型溞的生长、繁殖、摄食等生命活动。论文为评估NP在水生生态系统中的污染风险和富集传递效应提供了一定的参考依据。

Bioaccumulation and Transfer of Nonylphenol in Chlorella pyrenoidosa and Daphnia magna

Nonylphenol (NP) is a typical environmental endocrine disruptor. Its bioaccumulation and transfer in the freshwater green algae Chlorella pyrenoidosa and the freshwater cladoceran Daphnia magna were investigated in this study. The results show that the 96 h median effective concentration (96 h￣EC50 ) of NP for C. pyrenoidosa is 3.13 mg?L￣1, and there exist clear dose and time effects in the influence of NP on the cell density and chlorophyll content of C.pyrenoidosa. In the toxicity test of NP on D.magna, the 48 h median lethal concentration (48 h￣LC50 ) for D.magna is 37.41 μg?L￣1, indicating that NP is a highly toxic substance. NP poses adverse effects on the growth and reproduction of D.magna. The bioconcentration factor (BCF) of C.pyrenoidosa for NP was 5 144.93 after 0.05 mg?L￣1 NP exposure for 4 h, and the accumulation amount reached 252.2 μg?g￣1 . After 12 h NP expo￣sure, the BCF of C.pyrenoidosa for NP reached 12 053.64, and the accumulation amount was 1 181.73 μg?g￣1. However, the accumulation amount of NP in the D. magnawas 3.6μg?g￣1 after it was fed with C.pyrenoidosapre￣viously exposed to 0.05 mg?L￣1 NP for 7 days. The accumulation amount in D.magna exposed to 0.05 mg?L￣1 NP for 10 days was 4.02 μg?g￣1 . These results demonstrate that C. pyrenoidosa has a high ability to accumulate NP rapidly, and NP in the body of D.magna is mainly from the feeding of C.pyrenoidosa exposed to NP, which sig￣nificantly inhibit the growth, reproduction and feeding of D.magna. This study suggests NP has adverse effects on aquatic organisms, which is useful for evaluating the long￣term ecological risk of NP in the aquatic ecosystem.