Kinetic Study of Enzymatic Hydrolysis of Lactose in Whey

Dairy industry is one of the largest industries that generate significant quantity of waste stream of which casein/cheese whey is the most abundant. Major constituent of whey is lactose and it contributes very high value of BOD and COD. Effort has been taken to convert the lactose, a disaccharide to fermentable sugar through enzymatic hydrolysis using commercially available enzyme β-galactosidase. The bioethanol derived from hydrolyzed wheylactose could thus be a cost effective and environment friendly solution for treating this highly polluting waste stream. In this work, the enzymatic hydrolysis of lactose in whey was studied at room temperature of 32C. The lactose concentration was estimated using DNSA (Dinitro salicylic acid) method. The concentration of the hydrolyzed product, glucose was measured using GOD-POD test. On the basis of the data analyzed, Michaelis-Menten kinetic model has been represented. The parameters were estimated using lineweaver-burk plot. The maximum rate of hydrolysis was found to be 4.38 L/mol/min. The catalytic efficiency of the enzyme for the reaction has also been determined and reported.