啤酒酵母生物吸附镉的研究

Biosorption of cadmium (Ⅱ) by Saccharomyces cerevisiae

研究了啤酒酵母在游离与固定化条件下对重金属离子Cd2 + 的生物吸附特性。灭活的啤酒酵母在适当条件下对Cd2 + 有较强的吸附作用 ,它的吸附能力受到酵母浓度、Cd2 + 浓度、pH值和固定化方法等的影响。结果显示 :实验条件下 ,啤酒酵母的最高吸附率达 93% ,此时的吸附能力为 4 6 .5mgCd2 + g干酵母。吸附后用 1mol L的HCl解吸 ,解吸率达 84 %。用海藻酸钙凝胶包埋法对啤酒酵母细胞进行固定化 ,固定化细胞对Cd2 + 的吸附主要受到海藻酸钠浓度和CaCl2 浓度的影响 ,且凝胶本身对Cd2 +

The characteristics of cadmium (Ⅱ) biosorption by free and immobilized Saccharomyces cerevisiae were studied . The dry cells of Saccharomyces cerevisiae showed strong ability to biosorb Cd 2+ that was affected by cell concentration , Cd 2+ concentration, pH value and immobilization method. It turned out that the highest percentage of Cd 2+ biosorbed by Saccharomyces cerevisiae was 93% in the case of test conditions; accordingly the biosorption capacity was 46.5 mg Cd 2+ /g dry cells. The dry cells treated with 1mol/L HCl after biosorption, 84% of uptaked Cd 2+ could be desorbed to the solution. On the other hand, the uptake of cadmium by immobilized cells was greatly influenced by sodium alginate concentration and CaCl 2 concentration while the cells were immobilized in alginate beads, and the Cd 2+ biosorption by cell free alginate beads could not be negligible.