Chemical Properties
general term for various enzymes that hydrolyze polysaccharides (excluding cellulose and pectin) that constitute plant cell membranes. Their primary function is to hydrolyze β-1,4-glucan bonds in polysaccharides such as locust bean gum and guar gum to form beta-dextrins. Hemicellulases produced by three Aspergillus species have optimum pH values of 3.0, 5.0, and 5.5. The pH ranges for 100% activity after 24 hours at 30°C are 3.5-10, 2.5-6, and 4-7, respectively. The temperatures for 100% activity after 15 minutes at pH 5.6 are 50°C, 60°C, and 70°C, respectively. A nearly white to light gray amorphous powder or a light gray to dark brown liquid. Commercial products may contain food-grade diluents, carriers, stabilizers, and preservatives. Soluble in water, practically insoluble in ethanol, chloroform, and ether.
Biochem/physiol Actions
Hemicellulase is a group of enzymes that catalyzes the breakdown of heteropolysaccharides. It includes glucanases that act on glucan. Similarly, xylanases and mannanases breakdown xylan and mannan respectively. Hemicellulase is prevalent among various bacteria, fungi and plants.
