Strategies for Overcoming the Inhibition of Cellulose Hydrolysis

Lignocellulosic biomass biorefinery allows the conversion of the most abundant biomass into cascades of products. Cellulose present in the lignocellulosic biomass is the most abundant homopolymer of glucose linked by β,1-4 linkage and can be hydrolyzed by cellulase to give monomeric glucose. Cellulose hydrolysis into glucose via enzymes is the most sustainable way. Cellulase is a group of enzymes that act synergistically to break cellulose into glucose through hydrolysis. Glucose can be readily converted into fuels, feed, and other platform chemicals via microbial processes. Getting glucose in significant amount in the hydrolysate is a challenge as the high solid loading of biomass is required for it, which is associated with several shortcomings. These are pretreatment, scarcity of liquid medium for enzymatic interaction with the substrate, non-productive binding of cellulase with lignin, feedback inhibition of cellulase, temperature sensitivity of enzymes, etc. To resolve these issues there are a few strategies like the addition of additives like surfactants and cheaper proteins, the addition of biomass or enzymes in batches, using glucose tolerant and thermotolerant cellulase, reactor designing, etc. The strategies for overcoming the inhibition of cellulose hydrolysis are described in the chapter.