Cellulase refers to a group of enzymes which, acting together, hydrolyse cellulose. The b-glucosidases, including cellobiose, are primarily active on the smaller molecular weight cellulose hydrolysates. During cellulose breakdown they are active on the dimers and oligomers of cellulose.

• Readily soluble in water
• Enzyme Commission Number: E.C. 3.2.1.4

Cellulase from Aspergillus niger catalyses the hydrolysis of endo-1,4-β-D-glycosidic linkages in cellulose, lichenin, barley glucan, and the cellooligosaccharides cellotriose to cellohexaose. It does not cleave cellobiose or p-nitrophenyl-β-D-glucoside. This enzyme will also cleave intact glycosaminoglycan from a core peptide by hydrolysing the xylosyl serine linkage.

It is used for commercial food processing in coffee. It performs hydrolysis of cellulose during drying of beans. Furthermore, cellulases are widely used in textile industry and in laundry detergents. They have also been used in the pulp and paper industry for various purposes, and they are even used for pharmaceutical applications. It is used in the fermentation of biomass into biofuels, although this process is relatively experimental at present. Cellulase is used as a treatment for phytobezoars, a form of cellulose bezoar found in the human stomach.

Unit definition: One unit will liberate one µmole of glucose from cellulose in 1 H at pH 5 and 37 °C.