四尾栅藻对重金属镉胁迫的响应

通过不同浓度镉(0、0.5、1、3、5、7 mg·L-1)胁迫实验,对四尾栅藻(Scenedesmus quadricauda)的生长、色素、过氧化氢、超氧化物阴离子、可溶性蛋白含量进行分析,研究四尾栅藻对重金属镉胁迫的响应情况。实验显示:镉胁迫使四尾栅藻的生长受到抑制,在较高镉浓度(3~7 mg·L-1)下四尾栅藻的生长受到强烈抑制;随着镉浓度的上升,色素(叶绿素a、叶绿素b、类胡萝卜素)含量逐渐减少,过氧化氢、超氧化物阴离子含量增加,过氧化氢含量在镉浓度为5~7 mg·L-1时显著增多,超氧化物阴离子含量在镉浓度为7mg·L-1时显著增加;可溶性蛋白含量先增加,并在镉浓度为1 mg·L-1时达到最大值,之后随着镉浓度的上升而逐渐减小。研究结果表明,四尾栅藻对重金属镉有较好的耐受性(可以耐受1 mg·L-1的镉)。

Effect of Cadmium on Scenedesmus quadricauda

Heavy metal pollution is one of the most concerned water environmental problems. In this study, the effects of different Cd²⁺ concentrations on the growth, pigments, hydrogen peroxide, superoxide anion and soluble protein of Scenedesmus quadricauda were investigated in laboratory. Result showed that algal growth was inhibited under cadmium stress, especially under high cadmium concentrations(3~7 mg·L^-1). Pigment(chlorophyll a, chlorophyll b, and carotenoids) contents decreased with increasing concentrations of cadmium. Contents of hydrogen peroxide and superoxide anion increased significantly under 5~7 mg·L^-1 and 7 mg·L^-1, respectively. Soluble protein content reached the maximum at 1 mg·L^-1 and decreased afterwards. Scenedesmus quadricauda displayed better tolerance to cadmium(upto 1 mg·L^-1 cadmium).