汽爆玉米秸秆发酵丁醇的酶解工艺优化

摘要

Influence of different factors such as temperature, original substrate concentration, enzyme loading, hydrolysis time, and stirring rate on steam-exploded corn stover enzymolysis were studied to further improve reducing sugar concentration and butanol yield after reaction. It is found that the optimal hydrolysis reaction condition is:temperature 50℃, 100 r⋅min-1, enzyme loadings 60 IU/(g corn stover), solid:liquid ratio 3:10 and reaction time 48 h. Reducing Sugar concentrations were tested with DNS(3,5-Dinitrosalicylic acid) and butanol yield was tested with gas chromatographic methods. Moreover, the highest apparent viscosity and apparent viscosity of a 3-step loading are lower than those of 2-step loading. However, the sugar concentration is slightly higher than that of the later one. When the substrate with original concentration of 15%(w/w) was added with to final concentration of 25% (w/w) by 3 steps, the reducing sugar concentration and butanol yield reach to 89.23 mg⋅mL-1, 9.82 mg⋅mL-1, respectively, which show an increase of 58.63%, 44.20%, respectively.%为了提高秸秆酶解后的还原糖浓度和酶解液发酵后的丁醇产量，研究了不同因素对汽爆玉米秸秆酶解的影响，优化汽爆玉米秸秆秸秆发酵丁醇的酶解工艺。结果表明汽爆玉米秸秆的最佳酶解工艺为：反应温度50℃、原始底物浓度15%(wt)、酶用量60 IU⋅(g底物)-1、酶解时间48 h、搅拌器转速100 r⋅min-1。通过考察分步加料方式，三次加料方式最高表观黏度和反应后期表观黏度都低于两次加料的方式，而其糖浓度则略高于两次加料方式。当底物从原始浓度15%( wt)分三次加入到25%( wt)时，还原糖浓度、丁醇产量分别为89.23、9.82 mg⋅mL-1，分别增加了58.63%、44.20%。