响应面法优化耐高温酵母生产高浓度乙醇

Enhancing ethanol production using thermophilic yeast by response surface methodology

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35min,糖化酶添加量为1.21AGU/g底物,底物浓度为37.62%。20L发酵罐在此条件下(发酵温度37℃,转速100r/min)经过48h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%。

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 37℃ and 100 r/min. The ethanol content increased 33% than that under the original condition.