Cellulase
Cellulase is an enzyme that catalyzes the breakdown of cellulose into shorter sugars. It is produced by many fungi, bacteria, and other organisms.
Endoglucanase: An enzyme that cuts internal bonds in cellulose chains, creating shorter chains with new ends. It opens cellulose chains at internal sites, giving other cellulases more ends to attack.
Glycosidic bond: A covalent bond that links a sugar’s anomeric carbon to another group, often another sugar. Cellulases hydrolyze the beta-1,4 glycosidic bonds joining cellulose’s glucose units.
Cellulosic ethanol: Ethanol produced by fermenting sugars released from nonfood plant biomass. Cellulase releases fermentable sugars from biomass before or during ethanol production.
Elwyn T. Reese: An American microbiologist known for research on microbial degradation of cellulose. His work helped establish the modern study of microbial cellulase systems.
Hemicellulase: An enzyme that breaks down hemicellulose, a group of plant cell-wall polysaccharides distinct from cellulose. It targets neighboring wall carbohydrates rather than cellulose’s glucose chains.
Cellobiohydrolase: An enzyme that releases cellobiose units from the ends of cellulose chains. It processively removes sugar units from chain ends exposed by cellulose breakdown.
Beta-1,4 glycosidic bond: A glycosidic linkage joining the anomeric carbon of one sugar to carbon 4 of another in the beta configuration. This linkage gives cellulose its straight chains and defines cellulase’s principal cleavage target.
Lignocellulosic biomass: Plant-derived material composed mainly of cellulose, hemicellulose, and lignin. Its cellulose fraction is a major target for industrial cellulase preparations.
Cellulase complex: A coordinated set of enzymes that acts on cellulose through complementary activities. Research on synergistic enzyme action clarified why cellulose degradation often requires multiple cellulases.
Ligninase: An enzyme that oxidatively modifies or breaks down lignin, a complex aromatic plant polymer. It acts on lignin, which shields cellulose but is not a carbohydrate substrate for cellulase.