<正>以树干毕赤酵母(Pichiastipitis)为发酵菌株,利用海藻酸锰凝胶代替海藻酸钙,固定化酵母使用寿命明显增加。采用混合糖60g/L(50%葡萄糖、50%木糖)为发酵底物,以250mL三角瓶为反应器,在35℃、150r/min、pH5.0条件下,振荡发酵。结果表明,海藻酸锰树干毕赤固定化增殖酵母细胞能使戊糖和己糖同步发酵,海藻酸锰凝胶耐磷酸盐能力是海藻酸钙凝胶的3倍,海藻酸锰固定化树干毕赤酵母细胞乙醇发酵42d,固定化细胞稳定,总糖利用率为95.8%,乙醇得率为理论得率的92.3%,发酵稳定时间明显长于海藻酸钙固定化酵母细胞乙醇发酵的稳定时间(24d)。

The life time of immobilized Pichia stipitis yeast cells was prolonged greatly when the gel was formed with manganese alginate compared to that with calcium alginate.The ability of enduring phosphate of manganese alginate gel was increased 3 times than that of calcium alginate gel.Fermentation of glucosexylose mixture to ethanol was investigated in 250 mL shakeflask at 35 ℃,pH 5.0 and 150 r/min.Glucosexylose mixture could be cofermented to ethanol by immobilized Pichia stipitis yeast cells of manganese alginate.The results showed that immobilized cells of manganese alginate gel were still definite when fermentation of ethanol lasted 42 d,and utilization ratio of total sugar was 95.8%,yield of ethanol reached 92.3% of theoretical.While fermentation of ethanol by immobilized Pichia stipitis yeast cells of aluminum alginate only lasted 24 d.It provided the basis of theory for producing ethanol with immobilized cells in industry.