Research on Xylose-Cellulose Enzymatic Hydrolysis Fractionation of Corncob

[Objective] The aim was to optimize the acidic pretreatment,steaming pretreatment and xylan enzymatic hydrolysis process of xylose-cellulose enzymatic hydrolysis fractionation.[Method] The dry corncob was firstly treated with diluted acid and then steamed to study the effect of different factors on the xylose yield,and finally hydrolyzed with xylanase.[Result] The acidic pretreatment conditions were 1∶10 g/ml of solid-liquid ratio,0.5% H2SO4,70 ℃ water bath and 2.0 h treatment time,under the conditions,the loss rate of xylose was 4.72% and the yield of xylose hydrolysis was 30.03%.The steaming pretreatment conditions were: 1∶10 g/ml of solid-liquid ratio,120 ℃ hydrolysis for 2.0 h,under the conditions,the yield of xylose was 54.77% and the total yield of hydrolysis was 69.11%.The enzymatic hydrolysis conditions were: 5.0 pH,2 800 IU/g xylanase amount and hydrolysis at 50 ℃ for 36 h,under the above conditions,the yield was 83.41%.[Conclusion] The steaming pretreatment of corncob improved the yield of xylose,and the yield of xylose from the hydrolysis directly after single acidic pretreatment was not ideal.