Fractionation and hydrolysis of cellooligosaccharides by Trichoderma reesei Cellobiohydrolase 7A

Abstract

Abstract This study aimed to investigate the fractionation and hydrolysis of cellooligosaccharides by Trichoderma reesei Cellobiohydrolase 7A (TrCel7A). The enzyme TrCel7A was purified from enzyme mixture (Celluclast®). Fractionation of soluble cellooligosaccharides was performed using size exclusion chromatography (SEC) and hydrolysis of the cellooligosaccharides with degree of polymerisation (DP) from 3 to 6 was conducted by TrCel7A at 25 °C for 1 h, and the product concentration was analysed by highperformance liquid chromatography (HPLC). HPLC results showed that glucose was produced for each DP of cellooligosaccharides. However, the highest product that achieved for all DP of cellooligosaccharides was cellobiose, followed by cellotriose (in the case of DP 5 and 6) and glucose. The reaction of cellooligosaccharides with DP 3 to 6 during hydrolysis by TrCel7A were modelled to show exactly the cleavage sites for each DP of cellooligosaccharides. The model showed that all cellooligosaccharides was hydrolysed at the first (glucose) and second (cellobiose) glycosidic linkages by TrCel7A.