大型蚤标志酶用于城市二级出水毒性的评价

Toxicity evaluation of secondary effluent using enzyme biomarkers in Daphnia magna

大型蚤是一种国际公认的标准实验生物,广泛应用于污水、地表水等水质毒性检测。毒性水平较低的城市二级出水,对大型蚤往往无急性毒性效应,而具有慢性毒性效应,但慢性毒性检测周期过长,因此探索一种更灵敏的指标,实现快速检测,对于控制二级出水的水质风险具有重要意义。本研究考察了大型蚤在短期暴露于城市二级出水条件下,其体内乙酰胆碱酯酶、超氧化物歧化酶、过氧化氢酶、ATP酶、羧酸酯酶和碱性磷酸酯酶的酶活变化特征,从中筛选出对二级出水毒性响应灵敏的标志酶指标。实验结果表明,碱性磷酸酯酶、过氧化氢酶对二级出水毒性响应相对较灵敏,具有成为标志酶的潜力,研究结果为城市二级出水生物毒性评价方法优化提供新的思路。

Daphnia magna is a generally acknowledged standard animal tor btotoxtctty test, w widely used in biotoxicity test of wastewater and surface water. However, secondary effluent, which is much less toxic than wastewater,often has no acute toxicity but chronic toxicity to D. magna. Although the chronic toxicity test is more sensitive,it takes a longer experimental duration and can not supply a quick response. Therefore,it is important and urgent to find a rapid and sensitive biotoxicity test method for such samples. In this study,the en- zyme activity changes of acetylcholinesterase, superoxide dismutase, catalase, ATPase, carboxylesterase and alka- line phosphatase in D. magna were evaluated after exposure to secondary effluent, and the sensitive enzymes were identified. The result showed that alkaline phosphatase and catalase responded strongly in a short time, and could be used as enzyme biomarkers in biotoxicity evaluation of secondary effluent. This study indicates a promising and quick way for toxicity evaluation of secondary effluent.