Immobilization of β-glucosidase on Eupergit C for Lignocellulose Hydrolysis

Abstract

beta-Glucosidase is frequently used to supplement cellulase preparations for hydrolysis of cellulosic and lignocellulosic substrates in order to accelerate the conversion of cellobiose to glucose. Typically, commercial cellulase preparations are deficient in this enzyme and accumulation of cellobiose leads to product inhibition. This study evaluates the potential for recycling beta-glucosidase by immobilization on a methacrylamide polymer carrier, Eupergit C. The immobilized beta-glucosidase had improved stability at 65 degrees C, relative to the free enzyme, while the profile of activity versus pH was unchanged. Immobilization resulted in an increase in the apparent Km from 1.1 to 11 mM: and an increase in Vmax from 296 to 2430 micromol mg(-1) min(-1). The effect of immobilized beta-glucosidase on the hydrolysis of cellulosic and lignocellulosic substrates was comparable to that of the free enzyme when used at the same level of protein. Operational stability of the immobilized beta-glucosidase was demonstrated during six rounds of lignocellulose hydrolysis.

Immobilization of β-glucosidase onto Magnetic Nanoparticles and Evaluation of the Enzymatic Properties

“…This model could be considered quite accurate and reliable for predicting the activity recovery for immobilized β-glucosidase. The activity recovery of several reported supports for β-glucosidase immobilization, such as magnetite (15-27%), chitosan (25.1%), sol-gel beads (28%), sodium alginate (28.2%), Eupergit C (30%), S-layer (37%), and agarose matrix, functionalized with distinct reactive groups (80%), were still low (Balogh et al 2005;Fan et al 2011;O'Neill et al 2002;Palmeri and Spagna 2007;Su et al 2010;Tu et al 2006). Therefore, the activity recovery of the present method was much higher than other methods, and magnetic Fe 3 O 4 nanoparticles showed obvious advantages for enhancement of the activity recovery of immobilized β-glucosidase.…”

Energy from forest biomass in Ontario: Getting beyond the promise

“…The capital cost of a dilute acid pre-treatment process for a 200-Ml bioethanol plant is of the order of USD 25 million with dilute acid more costly and lime even more so (Eggeman andElander 2005, Chandra et al 2007). These costs may be reduced through optimization, which can reduce lignin condensation, chemical usage and cost for delignification, and partially reduce lignin inhibition (Tu et al 2006). It may also be possible to use a post-treatment chemical wash to remove lignin from a mechanically pretreated material .…”

“…Although the cost of commercial cellulase preparations has been reduced by up to 20-fold in recent years, enzyme costs are still an obstacle to full-scale process commercialization . Enzymes can also be utilized at lower costs if they are "recycled" by treating multiple batches of feedstock using the same batch of enzymes (Katchalski-Katzi and Kraemer 2000, Tu et al 2006).…”

The Development and Use of an Elisa-Based Method to Follow the Distribution of Cellulase Monocomponents During the Hydrolysis of Pretreated Corn Stover

“…As a result, a considerable amount of research has focussed on ways to try to improve the efficiency of hydrolysis while using low protein/enzyme loadings. Various strategies have been assessed, such as increasing substrate digestibility through biomass pretreatments [4,5], improving the efficiency of enzyme cocktails [6,7], and reusing the enzymes for multiple rounds of hydrolysis [8,9]. The last two strategies, in particular, have benefitted from better characterization of the specific roles and actions of individual enzymes and their synergistic interaction during cellulose hydrolysis.…”