Application of Used Tea as Solid Matrix for Immobilization of Alkaline Protease by OVAT Method

Enzyme immobilization on a solid matrix is nowadays widely employed, particularly in the food and pharmaceutical industries, in biomedical applications such as biosensors, immunological test systems, and in the production of fine chemicals. The conventional method of enzyme immobilization includes adsorption due to electrostatic and hydrophobic adhesion and covalent binding by internal cross-linkage of enzymes on a solid support. The immobilization of enzymes can offer several advantages including repeated usage of enzyme thereby reducing the cost of the enzyme, ease of product separation, and improvement in enzyme stability. The used tea, an abundant renewable source, can be applied as solid matrix for enzyme immobilization. In the present investigation, the immobilization of alkaline protease was studied on used tea. Immobilized enzyme showed better thermal stability than the free enzyme. Optimum conditions of immobilization investigated include temperature, pH and storage stability, and also reusability. The best result of immobilization yield (34%) and immobilization efficiency (45%) was found with 300 mg of solid matrix. The immobilized enzyme was activity even after eight cycles of repeated use.