蛋白核小球藻对叔丁基对羟基茴香醚的毒性响应

Toxic effects of Butylated hydroxyanisole to Chlorella pyrenoidosa

以蛋白核小球藻（Chlorella pyrenoidosa）为实验生物，从急性毒性及生化指标方面研究饲料添加剂叔丁基对羟基茴香醚（Butylated hydroxyanisole，BHA）对浮游植物毒性的影响，为该药物的生态毒性评价提供参考依据．结果表明BHA对小球藻生长有一定影响．BHA对小球藻的48hEC50为3．25mg／L，其安全质量浓度为0．33mg／L，毒性较大，属于中毒．BHA对小球藻体内谷胱甘肽硫转移酶（GST）和过氧化氢酶（CAT）产生明显的影响，对GSH和EROD的影响较弱．小球藻CAT活性受BHA诱导作用较显著，并随BHA暴露质量浓度的升高存在先诱导后抑制的现象，表现为典型“钟形曲线”．BHA质量浓度在1-10mg/L时，GST活性受到显著诱导，但随质量浓度进一步增高，当〉10mg/L后，GST活性趋于饱和．在低质量浓度BHA暴露条件下，CAT和GST适合作为BHA暴露的生物标记物．

The acute toxic and biochemical effects of Butylated hydroxyanisole （BHA） as a kind of aquaculture feed additives to Chlorella pyrenoidosa was assessed by a panel of bioassays. The results showed that the 96h ECs0 of BHA to Chlorella pyrenoidosa was 3.25mg/L, its security concentration was 0. 33 mg/L. The activities of Glutathione S-transferase （GST） and catalase （CAT） of Chlorella pyrenoidosa had been significantly affected under BHA exposure, while Glutathione （GSH） content and the activities of 7-ethoxyresorufin-O-deethylase （EROD） displayed less response to the BHA exposure. CAT was induced remarkably at lower concentration （ 〈5 mg/L） and inhibited at higher concentration （ 〉5 mg/L）, showing typical ＂bell＂ curves. GST was induced remarkably when the concentration of BHA ranged from 1 mg/L to 10 mg/L and GST activity tended to saturation with the further increasing of BHA concentration（ 〉 10 mg/L）. GST and CAT may be used as the candidate biomarkers of Chlorella pyrenoidosa in lower concentration BHA exposure.