普通小球藻对不同浓度镉胁迫的生理应答

以普通小球藻(Chlorella vulgaris)为研究材料探讨不同镉浓度对小球藻生理生化特性的影响。研究结果表明: 在5—40 μmol/L的Cd2+胁迫下, 普通小球藻的蛋白质、多糖和叶绿素含量均表现为随着Cd2+浓度的增加呈现逐渐增加的趋势, 30 μmol/L略高于对照组后又逐渐降低; 小球藻细胞中SOD活性及过氧化氢(H₂O₂)含量表现出先增加后减弱的趋势, 35 μmol/L时达到最大; 而小球藻中MDA含量随着Cd2+浓度的升高一直增加。这说明在重金属镉胁迫下小球藻会通过不同的生理应答来维持自身的正常生长代谢。

THE PHYSICAL RESPONSES OF CHLORELLA TO CADMIUM STRESS UNDER DIFFERENT CONCENTRATIONS

Cadmium is highly toxic to plant growth. It causes toxic effects on primary producers in water. The physiolo-gical and biochemical characteristics were investigated when Chlorella vulgaris was exposed to different concentra-tions of Cd2+. The results showed that the contents of protein, soluble sugar and chlorophyll in C. vulgaris cells in-creased under 5—40 μmol/L of Cadmium, and were slightly higher than those of the control group when the concentra-tion reached 30 μmol/L; however, they all gradually decreased when the Cadmium concentration was higher than 30 μmol/L. The SOD activity and H2O2 content increased firstly, and then decreased, which reached their peaks at 35 μmol/L. The content of MDA increased with the increase of Cd2+ concentration. These results indicated that C. vul-garis can respond positively to the heavy metal cadmium stress to keep their normal growth and metabolism.