Enhancing ethanol production using thermophilic yeast by response surface methodology / 生物工程学报

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