Abstract: Corn cob was pretreated by H₃PO₄-H₂O₂(PHP)solution and then hydrolyzed by cellulase. The conditions of pretreatment was optimized, which was based on saccharification rate of substrate. Results showed that in pretreated corn cob under the optimized conditions of pretreatment (mass fraction of H₃PO₄ 80%, 4 h, 50℃), the mass fraction of cellulose was 57.38%; the cellulose recovery, hemicellulose removal and lignin removal were 95.84%, 62.36% and 68.97%, respectively.As the dosage of cellulase was 10 FPIU/g glucan, the yield of 72 h enzymatic hydrolysis was 39.12%, which was 2.61 folds higher than that of the enzymatic hydrolysis yield of corn cob without pretreatment(10.84%). Using FT-IR to analyze the change of structure before and after pretreatment, the results showed that, PHP pretreatment had coordinated pretreatment effect in the pretreatment process, which could remove hemicellulose and lignin at the same time. For comparative purpose, H₃PO₄ (16.78%) or H₂O₂ pretreatment (20.71%) was used independently, to enzymatic hydrolysis of corn cob for 72 h. It was found that the yield of 72 h enzymatic hydrolysis treated by H₃PO₄-H₂O₂ pretreatment increased by 133.13% and 88.89%, respectively, while compared with that of H₃PO₄ or H₂O₂.

Key words: optimization, corn cob, structural changes, cellulose, enzymatic hydrolysis