EXTRACTION, PURIFICATION AND CHARACTERIZATION OF BETA-GALACTOSIDASE (EC 3.2.1.23) FROM WATER MELON SEED (Citrullus vulgaris)

Abstract

β-Galactosidase, hydrolyses the lactose into glucose and galactose and it is most commonly used in food based technology, particularly in the dairy manufacturing industry. β-D-galactosidase also known as lactase was an enzyme or protein which catalyzes the hydrolysis of lactose. This lactose is the main and foremost carbohydrate present in most of the dairy products, which is hydrolyzed to monosaccharide glucose and galactose. β-Galactosidase (β-D-galactoside-galactohydrolase, EC 3.2.1.23) was extracted from Watermelon seeds, Citrullus vulgaris purified in protein purification steps and characterized biochemically. The enzyme was precipitated with 70% ammonium sulphate solution. After that, it was subjected to Sephadex G-25 filtration. The activity of the enzyme was determined. The optimum temperature was 47ºC and the optimum pH to be 5.6 The average values of Michalis-Menten constant (Km), maximum velocity (Vmax ) were evaluated to be 0.1 and 1.667, respectively using Dano milk as substrate.