响应面法优化耐高温酵母生产高浓度乙醇

Enhancing ethanol production by using thermophilic yeast by response surface methodology

摘要:

利用耐高温酵母GXASY-10菌株对木薯粉同步糖化 (SSF) 法生产高浓度乙醇的发酵条件进行了优化。在单因素实验的基础上，首先应用Plackett-Burman试验设计筛选影响酒精高温高浓度发酵的重要参数，采用最陡爬坡实验逼近最大酒精生产区域后，利用Box-Behnken设计确定重要参数的最佳水平。筛选结果表明，影响酒精产量的重要参数是液化时间、糖化酶用量和初始木薯粉 (底物) 浓度。最佳工艺条件为：液化时间为35 min，糖化酶添加量为1.21 AGU/g底物，底物浓度为37.62％。20 L发酵罐在此条件下 (发酵温度37℃，转速100 r/min) 经过48 h发酵，酒精浓度可达16.07％ (V/W)。优化条件与初始条件相比较，酒精浓度提高了33％。

Abstract:

We optimized the conditions of simultaneous saccharification and fermentation (SSF) from cassava flour into high-concentration ethanol by thermophilic yeast GXASY-10. Based on the single factor experiment, we screened the important parameters by Plackeet-burman design. We used the path of steepest ascent to approach to the biggest region of ethanol production subsequently. Then, we obtained the optimum values of the parameters by Box-Behnken design. The results showed that the important parameters were the liquefaction time, glucosidase dosages and initial concentration of cassava flour (substrate). The optimum technical conditions were as follows: liquefaction time 35 min, glucosidase dosages 1.21 AGU/g substrate and initial substrate concentration 37.62%. Under such optimum conditions, the ethanol yield of 20 L fermentor reached 16.07% (V/W) after 48 h fermentation at 37oC and 100 r/min. The ethanol content increased 33% than that under the original condition.