RESUMO
High-concentration sugars production from stover is an important perspective technology for the cellulosic ethanol industrialization. Fed-batch process is an effective way to achieve this goal in the fermentation industry. In this study, based on fed-batch process, high-concentration sugars were produced from pretreated corn stover by enzymatic hydrolysis. After being pretreated by the dilute sulphuric acid, the impacts of the ratio of solid raw material to liquid culture, the content of supplementary materials and the refilling time on the saccharification rate were investigated. Results showed that the initial ratio of solid raw material to liquid culture was 20% (W/V) and the initial concentrations of enzymes for xylanase, cellulose and pectinase were 220 U, 6 FPU, and 50 U per gram of substrates, respectively. After 24 hours and 48 hours, 8% pretreated corn stovers were added respectively together with the additions of xylanase (20 U) and cellulose (2 FPU) per gram of substrates. After 72 hours, the final concentration of reducing sugar was increased to 138.5 g/L from 48.5 g/L of the non fed-batch process. The rate of enzyme hydrolysis of the raw material was 62.5% of the thoretical value in the fed-batch process. This study demonstrated that the fed-batch process could significantly improve the concentration of reducing sugar.