一株中型假丝酵母发酵木糖产乙醇的特性研究

本研究对自然界中筛选得到的1株可以发酵木糖产乙醇的中型假丝酵母(Candida intermedia)的特性进行了研究.该菌株在28℃、120 r/min、72 h条件下,发酵3%木糖的乙醇产率最高,达到理论值的43.70%,发酵7%木糖得到的乙醇产量最高,为6.480 g/L.发酵时间延长到156 h,可以利用8%木糖产乙醇21.225 g/L,产率为理论值的72.87%.该菌株还可以在同样条件下,发酵13%葡萄糖得到乙醇50.965 g/L,达到理论值的76.90%.以3% 2% 3%分批补加糖,比一次性发酵8%木糖的乙醇产量提高9.91%.在葡萄糖和木糖的混合培养基中,优先利用葡萄糖,同时还表现出葡萄糖对木糖发酵的促进作用,当2%的木糖与6%葡萄糖混合时,乙醇产量比两者单独发酵的加和提高了25%.

Characters of Ethanol Producing Candida intermedia Yeast in Xylose Fermentation

Characters of one Candida intermedia yeast strain which isolated from nature can produce ethanol from xylose-fermenting been systemic studied. In conditions 28°C, 120 r/min, 72 h, it can produce 6.480 g/L ethanol from 7% xylose and 43.70% theoretical production of ethanol from 3% xylose. It can produce up to 21.225 g/L ethanol when incubation time prolong to 156 h from 8% xylose. It also can ferment 13% glucose produce 47.647 g/L ethanol and reach 76.90% of theoretical ethanol production, respectively. Compared to CK, ethanol productivity can be improved 9.91% when add 8% xylose in three times as 3%, 2% and 3%, respectively. Glucose can be first utilized in the mixture sugar medium. When the ratio of xylose vs. glucose is 3:1in mixture sugar, the productivity of ethanol can be improving 25%.