壳聚糖球固定化酵母细胞的研究

以戊二醛为交联剂,将壳聚糖球交联引入醛基,然后将交联的壳聚糖球浸泡在酵母细胞悬浮液中,制备了固定化酵母细胞壳聚糖球。以苯乙酮酸为底物,催化合成了D-扁桃酸。最优固定化条件是戊二醛的质量分数w(GA)=1%,酵母细胞与交联壳聚糖球的质量比m(Y):m(CB)0=0.5,交联时间为6h,固定化时间为18h,底物浓度为10mmol/L,在此条件下反应最大转化率和产物光学纯度分别高达67.86%和98.05?。固定化酵母壳聚糖球具有良好的重复使用性和贮存稳定性。

Immobilization of Saccharomyces Cerevisiae Cells Using Chitosan Beads Carrier System

Saccharomyces cerevisiae cells were immobilized onto the crosslinked chitosan beads containing aldehyde groups that were prepared in the presence of glutaraldehyde.Asymmetric microbial reduction of phenylglyoxylic acid to D-mandelic acid with immobilized cells was studied.The optimum conditions of immobilization were 1% w(GA)of glutaraldehyde mass fraction, 0.5 of yeast cells/beads weight ratio,6h of the crosslinking time,18h of the immobilization time and 10 mmol/L of substrate con- centration.The conversion ratio and optical purity of the product were as high as 67.86% and 98.05?,respectively.The immobi- lized yeast cells on chitosan beads have good reusability and storage stability.