Biocatalytic transformation of semi-finished hardwood into sugars – carrying out the process of enzymatic hydrolysis at a high concentration of substrate

The possibility of exhaustive enzymatic hydrolysis of semi-bleached sulfate hardwood pulp, a semi-finished product of pulp and paper production, at its super high concentrations in the reaction mixture (up to 300 g/l) is shown. For hydrolysis, Russian commercial enzyme preparations were used, the best of them was Agroxyl Plus, which has a high activity of cellulases and endoxylanase. With the help of Agroxyl Plus (at its dosage of 20 mg protein/g substrate) in the presence of an auxiliary enzyme preparation of β-glucosidase (2 mg protein/g substrate) at an initial concentration of semi-bleached cellulose of 300 g/l, 290 g/l sugars (210 g/l glucose, 30 g/l xylose) were obtained. Due to fed-batch enzymatic hydrolysis, it was possible to halve the dosage of Agroxyl Plus (10 mg protein/g of substrate at a total concentration of semi-bleached cellulose of 300 g/l) while maintaining a high yield of hydrolysis products – 270 g/l sugars (200 g/l glucose, 30 g/l xylose).