二溴联苯醚对纤细裸藻的生态遗传毒性效应

通过检测纤细裸藻生长、抗氧化酶活性和单细胞凝胶电泳(彗星试验)研究了4,4’-二溴联苯醚(BDE-15)对纤细裸藻(Euglena gracilis)的生态遗传毒性效应.结果表明,低浓度BDE-15(3×10-6mg/L)对纤细裸藻的生长无显著影响,高浓度时(3mg/L)具有明显的抑制作用,相比空白抑制率达69.70%;叶绿素a和类胡萝卜素含量在高浓度BDE-15作用下显著上升;谷胱甘肽(GSH)和细胞总蛋白含量则随BDE-15浓度增加明显下降;抗氧化酶系统中超氧化物歧化酶(SOD)活性随BDE-15浓度升高显著下降,具明显的剂量-效应关系,过氧化物酶(POD)活性随BDE-15浓度增加呈上升趋势,最高浓度组(3mg/L)比空白对照提高93.45%,显示BDE-15胁迫可诱导抗氧化酶活性;彗星试验结果显示纤细裸藻细胞DNA损伤程度随BDE-15浓度增加而加重,表明高浓度BDE-15具有潜在致突变性.

Ecogenotoxicological effects of BDE-15 on the Microalga Euglena gracilis

The potential ecogenotoxicities of 4, 4’-dibromodiphenyl ether (BDE-15), one of polybrominated diphenyl ethers (PBDEs) were investigated by detecting its effects on growth, pigment contents, antioxidant enzyme activities and DNA damage in microalgae Euglena gracilis. At lower concentrations (3×10-6 mg/L), BDE-15 showed no notable effect on the growth of E. gracilis, while at higher concentration (3mg/L), the growth was restrained to 69.70% compared with the control, meanwhile the content of photosynthetic pigments increased. Glutathione (GSH) and protein contents decreased with the increase of BDE-15 concentration. In addition, there was an obvious decrease and dose-effect relationship in SOD activity with the increase of BDE-15 concentration. At higher concentration (3mg/L), POD activity increased by 93.45% compared with the control, which indicated that BDE-15 could induce the activities of antioxidant enzymes in E. gracilis. The degree of DNA damage observed from the comet assay increased with BDE-15 concentration increasing, which suggested that high dose of BDE-15 may have potential mutagenicity on E. gracilis.