【摘要】 利用海藻酸锰凝胶包埋,将低浓度的树干毕赤酵母(Pichiastipitis)细胞固定,其凝胶颗粒直径约2～3mm,经增殖培养,进行乙醇发酵低pH值处理研究。结果表明,以低pH值(3.8、2.8、2.4)无菌水处理海藻酸锰固定化酵母细胞凝胶珠2～3h,再恢复正常pH值5.0。当用pH值2.8无菌水处理时,细菌基本上被杀死,而酵母细胞功能不受影响;当pH值2.4时,对酵母细胞影响较大,电子显微镜下观察,酵母细胞由椭圆形变成细长形或不规则形状,其乙醇代谢功能严重受损。更多还原

【Abstract】 Pichia stipitis yeast cells were immobilized by entrapment in marine alga manganese gel,the resulted gel beads with a diameter of 2-3 mm were further incubated to study the fermentation of ethanol under the condition of low pH value.The yeast cellimmobilized gel beads were treated at low pH value(3.8,2.8,2.4) respectively for 2-3 h,followed by normal pH value 5.0.When pH value was 3.8,most bacteria were killed after such a treatment,while stabilization of immobilized cells was not affected significantly.When treated at pH value 2.4 or below,however,immobilized cells were injured under electronic microscopic observation,and it was difficult to recover the function,and shape of yeast cells changed into slim or irregular state from the original ellipsoid.更多还原