产朊假丝酵母生物吸附Cu2+影响因素及吸附机理的研究

选取产朊假丝酵母作为生物吸附材料,在确立Cu2 最佳吸附条件的基础上,通过细胞内pH值荧光探测剂测定酵母吸附重金属前后的pH值变化,以及运用phengreen细胞内外重金属荧光探测剂进行重金属分布定位,对酵母生物吸附的机理进行了初步的探讨.实验结果表明,最佳吸附条件为PH 4.49～5.04,酵母]:Cu2 ]为60:1;酵母细胞内pH值随吸附时间的增加而有所升高,并由酸性变为弱碱性,与此同时酵母死亡率也随吸附时间的增加而迅速增加;生物吸附主要集中在细胞壁的结合位点上,在细胞内部基本没有;生物吸附过程分为2个步骤,首先是一个快速过程,然后是一个慢速过程,但吸附中出现的慢速过程并不一定代表重金属由细胞外进入细胞内.

The study of influencing factor and biosorption mechanics of candida utilis adsorption on copper ion

The biosorbent was prepared from the Candida utilis. After getting optimum adsorption conditions, we measured the intracellular pH of different adsorption time by BCECF, located the distribution of copper ion by PhenGreen dipotassium salt and diacetate, studied the biosorption mechanics. The results showed as following: optimum adsorption appeared when pH is from 4.49 to 5.04 and the ratio of yeast and copper ion concentration is 60 to 1. The intracellular pH of yeast stepped up when biosorption was proceeding and the mortality rate of yeast also increased with the increase of adsorption time. The bioadsorption appeared on active site of cell walls, while the intracellular cell had no. The adsorption process included the two parts of fast step and slow step. But slow step did not stand for the copper ion's transfer from cell surface to inside cell.