利用中温蒸煮工艺进行高浓度酒精发酵

High-concentration Ethanol Production from Cooked Corn Starch by Using Middle-temperature Cooking Process

用中温蒸煮工艺生产高浓度酒精,首先利用耐高温α-淀粉酶在95～97℃下同时糊化和液化淀粉,接着在60℃下加高转化率的糖化酶进行糖化,最后在30℃下加酵母菌悬液进行发酵。酵母菌W4在60h内可以产生18.3％的乙醇,在成熟发酵醪中的残还原糖和总糖分别为1.2％和4.1％,细胞存活率为68.5％。如果在发酵培养基中添加一定量的硫酸铵,可进一步改进这一工艺,使成熟发酵醪的乙醇浓度提高到18.9％,发酵周期缩短到50h,残还原糖和总糖分别减少到0.27％和3.1％。

An improved process for high-concentration ethanol production from cpoked corn starch by Saccharamyces sp. W4 was well developed. Simultaneous cooking and liquefaction of corn starch were performed by using thermophilic a-amylase at 95-105℃. The mash was then saccharified at 60℃ by using high-efficiency glucoamylase. Saccha-romyces sp. W4 could produce 18. 3% ethanol at 30℃ within 60℃ hours with 1. 2% reducing sugar and 4. 1% total sugar remaining in the fermented mash. It is found that ammonium sulphate could accelerate the fermentation rate. When 0. 9g of ammonium sulphate was added to 280 ml of the fermentation media, 18.9% ethanol could be reached in the mash after 50 hours of fermentation, leaving 0. 27% reducing sugar and 3. 1% total sugar in the fermented media.