Optimum mixture and synergy analysis of three main cellulases

Abstract

Endo-1, 4-β-glucanase (Eg), 1, 4-β-D-glucan cellobiohydrolase B precursor (CbhB) and 1, 4-β-glucosidase (Bgl) are major components of cellulase. The three enzymes synergistically hydrolyze cellulose to glucose. Cellulases with a poor ratio of, or unbalanced enzyme components do not have a noticeable effect. Therefore, it is crucial to optimize the composition of cellulase mixtures and promote the synergy between key enzymes. We isolated and purified Eg, CbhB and Bgl to determine the optimal ratio and effect of these three cellulases. First, we carried out a pairwise-cooperation experiment to determine the optimal synergetic ratio. We then determined the optimal degradation ratio. The optimal synergistic effect of Eg (34.38%), CbhB (33.35%) and Bgl (32.27%) was found with Design-Expert. Best coordination was 4.199°, which is close to the theoretical value of 4.206°. The degradation of filter paper and absorbent cotton was studied with different combinations of Eg, CbhB and Bgl. The progressive and binding rates followed the order (Eg + CbhB + Bgl) > Eg + CbhB > Bgl, indicating that the three-enzyme combination promotes cellulase activity synergistically, providing a theoretical basis for industrial production.