THE INFLUENCE OF XYLAN ON THE PROCESS OF ENZYMATIC HYDROLYSIS OF BLEACHED KRAFT PULP

Enzymatic hydrolysis of cellulosic materials allows to obtain monosaccharide's, which are the starting materials for the further processing into useful products. Xylan and xylooligosaccharides have been found to be negative factor for the hydrolysis of cellulose. At the same time, there remains actual problem of the influence of xylan on enzymatic hydrolysis of industrial substrates. The aim of this study was to investigate the inhibitory effect of xylan on the process of enzymatic hydrolysis of cellulosic substrates. In this work, birchwood xylan clearly inhibited the enzymatic hydrolysis of bleached kraft pulp. Hydrolysis efficiencies of industrial product based on Trichoderma reesei and the enzyme preparation based on Penicillium verruculosum were inhibited by birchwood xylan. It has been found that the further addition of 2.5 mg/ml of xylan reduced yield of hydrolysis of 4.3...8.5 %, and adding 5...7.5 mg /ml xylan 6.6...29.6 %, respectively. It was found that the addition of kraft pulp hydrolysate reduces the hydrolysis yield of 5.1 %. The results in this work demonstrated that xylan inhibited enzymatic hydrolysis of bleached kraft pulp.