高含量己糖玉米芯纤维素酶解液发酵产酒精的研究

Ethanol Production by Fermentation of Corncob Hydrolysate with High Ratio of Hexose Prepared with Cellulase

将玉米芯粉碎成1～2cm3的颗粒,15g/100mL硫酸喷雾浸润,萃取脱去其中戊糖后进行三级逆向酶解和萃取工艺,得到质量浓度为10.26g/100mL的己糖水解液。利用酒精酵母进行此高质量浓度的己糖酶解液进行发酵,以酒精产率为响应值,对MgSO4、KH2P O4、CaCl2的添加量,以及豆粕水解液、麸皮水解液、酵母泥添加量,共6个影响因素进行Plackett-Burman试验设计,优化其发酵条件。结果表明:Plackett-Burman试验确定MgSO4、KH2PO4和豆粕水解液为显著影响因素,经最陡爬坡和中心组合试验得到得到MgSO40.045g/100mL、KH2PO40.135g/100mL、豆粕水解液7.34g/100mL,在此条件下时发酵结果最佳,实际酒精产率为88.64g/L。

Corncobs were crushed into 1-2 cm^3, moistened by spraying 15g/100mL sulfuric acid, extracted for the removal of pentose, and then subjected to three-step countercurrent enzymatic hydrolysis and extraction. Hydrolysate with a hexose content of 10.26 g/100 mL was obtained. The fermentation of the hydrolysate by Saccharomyces cerevisiae HF2.0 for ethanol production was investigated. Placktt-Burman （PB） design was used to analyze the effects of MgSO4, KH2PO4, CaC12, soybean meal hydrolysate, wheat bran hydrolysate, and yeast mud added to the hydrolysate on ethanol production. MgSO4, KH2PO4 and soybean meal hydrolysate were identified as the main influential factors. As determined by steepest ascent tests and central composite design, the best fermentation results were obtained when the concentrations of MgSO4, KH2PO4 and soybean meal hydrolysate were 0.045, 0.135 g/100 mL and 7.34 g/100 mL, respectively, resulting in an ethanol yield of 88.64 g/L.