响应面法优化水/醇处理后汽爆玉米秸秆酶解

为了提高水/醇处理后汽爆玉米秸秆的酶解还原糖产率,对其酶解条件进行了优化。通过响应面优化法确定了底物质量浓度为53.28 g/L,纤维素酶用量为53.32 FPU/g,酶解时间为60.45 h时,还原糖产率可达672.36mg/g,与秸秆物料及汽爆后物料相比,酶解还原糖产率分别提高了170.46%和28.97%。化学组分及结构形貌分析表明,汽爆水/醇处理后物料纤维素含量显著增加,物料相对结晶度增高,其结构更有利于纤维素酶分子的吸附。

Optimization of Enzymatic Hydrolysis Process of Corn Stalk by Water/Ethanol Extraction after Steam Explosion

In order to improve the production of reducing sugar yield from corn stalk by water/ethanol extraction after steam explosion,the enzymatic hydrolysis process was optimized.By adopting the response surface methodology,the production of reducing sugar yield can reach 672.36 mg/g under the following conditions:the substrate mass concentration is 53.28 g/L,the cellulase loading is 53.32 FPU/g and the reaction time is 60.45 h.Compared with untreated and steam exploded corn stalks,the production of reducing sugar yield increased by 170.46% and 28.97% respectively.The chemical composition of untreated/treated corn stalk was investigated and their structures were detected by means of scanning electron microscope(SEM) and X-ray diffraction(XRD).The results show that the relative content of cellulose in corn stalk treated by water/ethanol extraction increased significantly,and the relative crystallinity was improved,but the changes of structure lead to easier adsorption of the cellulase molecules.