Cd胁迫对受驯杜氏盐藻生长影响的研究

Influence of cadmium stress to the growth of metal-trained Dunaliella tertiolecta

研究了经低浓度Zn和Cd驯化的杜氏盐藻（Dunaliella tertiolecta）在不同浓度Cd胁迫条件下的生长状况，并通过微分脉冲极谱法测定了微藻细胞的Cd吸收量。结果表明经zn驯化的杜氏盐藻生长力和耐受力要强于Cd驯化藻，二者的半抑制浓度（IC50）分别为29和26μmol／L；最大比生长率都出现在低浓度Cd胁迫组，分别为0．36和0．24。暴露实验结束后，各个浓度组收获藻细胞干重在13．46～51．90和9．90～54．33mg／L，藻细胞的Cd吸收量则分别在20．17～144．58和93．67～180．64μg／10^9 cells。Cd驯化杜氏藻相对更易吸收富集重金属，且金属Cd一旦进入细胞体就很难代谢去除。两种金属驯化藻体内的Cd吸收量与收获的生物量干重具有一定的线性关系。

The growth of metal-trained Dunaliella tertiolecta challenged with different Cd concentration stress was studied and the algae intracelluar Cd contents were determined by differential pulse polarography（DPP） technique in this paper. The results showed that the growth and tolerance abilities of Zn-trained D. tertiolecta are stronger than Cd-trained D. tertiolecta. Their IC5o are 29 and 26μM relatively ; and the most specific growth rates are 0.36 and 0.24, which all occurred in low Cd concentrations groups. At the end of expo- sure, the harvest dry weights of algae range from 13.46 ～ 51.90 and 9.90～54.33 mg/L, Cd uptake contents vary from 20. 17 - 144.58 and 93.67 ～ 180.64μg Cd/109 cells. It implies that Cd-trained D. tertiolecta be liable to absorb and accumulate heavy metals and difficult to exclude them. In addition, a good linear relationship was observed between the intracelluar Cd contents and dry weights of algae.