溴化1-己基-3-甲基咪唑对斜生栅藻谷胱甘肽及其代谢酶的影响

研究了浓度为0、1、5、10、15、20 mg/L的新兴离子液体溴化1-己基-3-甲基咪唑(C6mim]Br)在24h、48h、72h和96h对斜生栅藻还原型谷胱甘肽（GSH）及其代谢酶-谷胱甘肽过氧化物酶（GPX）、谷胱甘肽转硫酶（GST）和谷胱甘肽还原酶（GR）的影响。结果表明：GSH含量在24h、48h和72h时，在最低处理浓度下不变，其他处理浓度下随胁迫浓度增加而降低，96h时则与对照无差异或较小；GPX和GST的活性在72h之前明显升高（最高浓度组的GST活性有波动），96h时均降低至对照水平；GR活性在24h时，C6mim]Br=1 mg/L时升高，之后降低，在48h增高至对照水平，72h时，C6mim]Br≥10 mg/L的处理组高于对照水平，96h时，除最低处理组外，均降至对照水平以下。GR是GSH系统中的限速酶，GST则是该系统中活性和灵敏性最高的酶，可作为C6mim]Br胁迫时的敏感的生物标志物。1 mg/L的C6mim]Br可引起藻细胞的氧化胁迫，具有环境毒性。

Responses of glutathione cycle enzymes and glutathione metabolism to 1-hexyl-3-methylimidazolium stress in Scenedesmus obliquus

The effects of ionic liquid 1-hexyl-3-methylimidazolium (C6 mim] Br), with the concentrations of 0, 1,5, 10, 15 and 20 mg/L and exposed for the 24, 48,72 and 96h respectively, on glutathione (GSH) and the enzymes in glutathione metabolism of Scenedesmus obliquus such as glutathione peroxidase (GPX) , glutathione S-transferases (GST) and glutathione reductase (GR) were studied in the present study. The results indicated that the GSH contents decreased with the concentration of C6 mim] Br increasing at the 24, 48 and 72h, but it did not change when C6 mim] Br = 1 mg/L. The GSH contents were similar to or lower than that of the control level at the 96h. The activities of GPX and GST increased markedly before 72h except for the activity of GST at the highest concentration (20 mg/L), but they both decreased to the control level at the 96h. The activities of GR increased at the concentration of 1 mg/L and then decreased with the concentration increasing at the 24h, increased to the control level at the 48h, and then reached its peak at the 72h (when C6 mim] Br≥10 mg/L the GR activities exceeded the control level), but at the 96h, it decreased markedly even weaker than the control level. GR was the enzyme that limited the reaction velocity in the system of glutathione cycle and the GST was the most active and sensitive enzyme. It could be used as sensitive biomarkers under the stress induced by C6 mim] Br. C6 mim] Br induced oxidative stress of S. obliquus at the concentration of 1 mg/L and had environmental toxicity.