【摘要】 以树干毕赤酵母为发酵菌株,高混合糖(木糖、葡萄糖)为发酵底物,确定树干毕赤酵母高糖浓度发酵时所需的条件.研究结果表明,在高糖浓度乙醇发酵中,树干毕赤酵母较为适宜的发酵温度为30℃,发酵24h,残糖浓度和乙醇浓度分别为0.1g/L和32.5g/L.添加硫酸铵1.1g/L+微量元素发酵效果较好,乙醇浓度为33.2g/L.由典型发酵过程中各物质浓度变化曲线可知,酵母优先利用葡萄糖,发酵12h葡萄糖和木糖的还原糖利用率分别为89.3%、10.7%.待12h葡萄糖几乎被消耗完后,对木糖的利用开始占主导地位,乙醇浓度随着糖的不断消耗而逐渐提高.发酵28h时乙醇浓度最高,达到33.2g/L.更多还原

【Abstract】 Fermentation of glucose-xylose mixture to ethanol was investigated with Pichia stipitis.To definite the conditions of high sugars concentration fermentation through changes of cultivation conditions.The results of study showed that it was fit for 30℃ of temperature in high sugars concentration fermentation.And the concentration of left sugars and ethanol were 0.1g/L,32.5g/L respectively for fermentation in 24h.It was better for adding(NH4)2SO4 and trace elements in fermentation.The concentration of ethanol was 33.2g/L.Glucose was first used by yeast from typical curve of fermentation.The utilization rates of glucose and xylose were 89.3%,10.7% respectively.It was main use of xylose after 12h.The concentration of ethanol increased with less of sugars.The concentration of ethanol reached maximum in 28 h of fermentation which was 33.2g/L.更多还原