Abstract：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.
