Page 443 - Demo

SECTION II. APPLIED BIOTECHNOLOGY IN THE PHARMACEUTICAL INDUSTRY... 447the positive effects of non-ionic surfactants in the enzymatic hydrolysis of cellulose on different cellulose sources have been shown. The positive effects of surfactants are believed to be: (1) increasing the stability of activity of enzymes, preventing enzyme denaturation during hydrolysis; (2) Surfactants can affect the structure of the substrate and make it easier to access than in enzymatic hydrolysis; (3) together with the participation of surfactants, it has a positive effect on the interaction of enzyme-cellulose, leading to the increase of efficiency of cellulose conversion. In the research, the investigated conditions helped the enzyme Cellic Ctec 2 maintain hydrolytic stability for 72 hours and release high glucose content of about 180.8 g/L in the hydrolyzed solution (Figure 2 - B).4.2. Effect of surfactants on the substrate The effect of surfactants reduces the adsorption capacity of cellulase enzymes on the substrate by the lignin-enzyme complex [15]. The effect of Tween 80 on the desorption of cellulase (Celluclast 1.5L and Novozyme 188) bound to acid-insoluble lignin in corn husks to form lignin-enzyme complexes reduces the hydrolysis efficiency from 43.6% to 21.5% [16].This reduction in hydrolysis efficiency is because the hydrolysis capacity of the enzymes is lower than the desorption of the enzymes from lignin, which may be related to the competitive adsorption between the enzymes and Tween 80 on lignin. In addition to the competitive effect between surfactants and enzymes to interact with lignin, the presence of surfactants reduces the affinity between cellulase and lignin, which contributes to the increase of the desorption of enzymes [17]. Also according to the study of Malmsten et al. [18], the non-specific adsorption of surfactants on cellulose fibers is due to the fact that lignin molecules in the pretreatment process with formic acid have not been completely removed or only the