木薯粉与甘蔗汁混合发酵生产高浓度乙醇

Very high gravity ethanol fermentation with cassava flour and sugarcane juice

对木薯粉和甘蔗汁混合原料进行高温高浓度乙醇发酵的条件进行了优化,在单因素实验的基础上,先应用Plackett-Burman试验设计筛选出影响发酵的重要参数,再利用正交试验设计确定重要因素的最佳水平,即:木薯粉与甘蔗汁的比例为1∶5(W/V),发酵初始pH为4.0～4.5,尿素添加量为0.25%(W/W),硫酸镁添加量为0.04%(W/W)。最后在发酵过程中采用梯度温度控制,可显著提高发酵效率。在技术集成的基础上,进行了2L发酵罐放大实验,经过48h发酵,发酵成熟醪乙醇浓度可达17.84%(V/V),发酵效率达91.82%。

We optimized the conditions of mixed fermentation of very high gravity ethanol with cassava flour and sugarcane juice. Based on the single factor experiment,we screened the important parameters for very high gravity ethanol fermentation with cassava flour and sugarcane juice by the Plackeet-burman design. Then,we obtained the optimum values of the important parameters by the orthogonal experiments：the mixing ratio of cassava flour to sugarcane juice,1：5; initial pH of fermentation,4.0？4.5; the concentrations of urea and MgSO4,0.25% and 0.04% （W/W）,respectively. Finally,we used a gradient temperature control strategy with the optimized conditions,and ethanol concentration of 17.84% （V/V） and fermentation efficiency of 91.82% were achieved,correspondingly.