木糖发酵生产乙醇的研究

Ethanol production of xylose fermentation by Pichia stipitis

选育出一株优良的木糖发酵菌株树干毕赤酵母菌 712 4 ,并利用纯木糖优化了木糖发酵条件。利用海藻酸钠固定化树干毕赤酵母菌增殖细胞 ,不仅能较好满足限氧发酵条件 ,而且能耐较高糖浓度 ,使乙醇发酵浓度提高到 2 0 g/l。利用半纤维素水解液进行了乙醇发酵的初步研究 ,基本达到了纯木糖发酵的效果。

Pichia stipitis NRRL 7124 was a good strain for ethanol production using xylose. The optimal conditions were as follows: xylose concentration, 20 g/L; fermentation temperature, 25℃; initial pH, 5.2 and shaking speed, 70 r/min. The proliferous cells were immobilized by sodium alginate, thus the strain not only met the limiting oxygen condition but also resisted high concentration of xylose. So the ethanol concentration reached 20 g/L. The primary results showed that using hemicellose hydrolysate was the same as using pure xylose.