镉胁迫对两种海洋微藻生长和抗氧化系统的影响

采用实验生态学和生物化学的方法,研究了不同含量Cd（Ⅱ）（0.05、0.1、0.5、1.0 mmol/L）对两种海洋微藻的可溶性蛋白含量、超氧化物歧化酶（SOD）活性、过氧化氢（H2O2）、丙二醛（MDA）和还原型谷胱甘肽（GSH）含量的影响。结果表明：0.05 mmol/L的Cd（Ⅱ）对湛江等鞭金藻Isochrysis zhan-jiangensis的生长无明显影响,与对照组相比,可溶性蛋白含量略微增加,而高浓度（〉0.05 mmol/L）的Cd（Ⅱ）对湛江等鞭金藻的生长有显著抑制作用,可溶性蛋白含量也迅速减少;普通小球藻Chlorella vul-garis的生长也明显受到Cd（Ⅱ）的抑制,可溶性蛋白含量减少。Cd（Ⅱ）胁迫抑制了两种藻类的SOD活性;随着Cd（Ⅱ）浓度增加,普通小球藻和湛江等鞭金藻的H2O2和MDA含量升高,普通小球藻的GSH含量升高,而湛江等鞭金藻的GSH含量在低浓度Cd（Ⅱ）胁迫下有所升高,高浓度时则下降。Cd（Ⅱ）胁迫对普通小球藻和湛江等鞭金藻的生长和抗氧化系统都产生了一定程度的影响。

Effects of Cd stress on growth and antioxidative system in two marine microalgae

Effects of different cadmium ion concentrations（0.05,0.1,0.5,and 1.0 mmol/L）on soluble protein content,activity of superoxide dismutase（SOD）,contents of hydrogen peroxide（H2O2）,malonaldehyde（MDA） and reductive glutathione（GSH） were studied in two marine microalgae via experimental ecology and biochemical approaches.The results showed that there was no significant effect of 0.05 mmol/L Cd（Ⅱ） on the growth of alga Isochrysis zhanjiangensis.However,the content of total protein was found to be increased slightly compared with that in the control group.High concentration Cd（Ⅱ）（0.1 mmol/L） significantly inhibited the growth of I.zhanjiangensis and reduced the protein content quickly.Chlorella vulgaris showed poor growth when exposed to Cd（Ⅱ） stress and lower level of soluble protein.The activity of SOD was inhibited by Cd（Ⅱ） both in C.vulgaris and I.zhangjiangensis.The content of H2O2 and MDA led to increase in two species exposed to high Cd（Ⅱ） concentration.The high content of GSH was observed in C.vulgaris exposed to high concentration of Cd（Ⅱ） whereas the high content of GSH was observed in I.zhanjiangensis at low Cd（Ⅱ）concentration.