Hydrolysis of lactose from cheese whey using a reactor with beta-galactosidase enzyme immobilized on a commercial UF membrane

REGENHARDT, SILVINA A; MAMMARELLA, ENRIQUE J; RUBIOLO, AMELIA C

Chemical and Process Engineering

Versita

Lugar: Warszawa; Año: 2013 vol. 34 p. 375 - 385

2300-1925

In this study, b-galactosidase enzyme from Kluyveromyces fragilis was immobilized on a commercial polyethersulfone membrane surface, 10 kDa cut-off. An integrated process, concerning the simultaneous hydrolysis?ultrafiltration of whey lactose was studied and working conditions have been fixed at 55°C and pH 6.9, the same conditions that are used for the industrial process of protein concentration. For the immobilization, best results were obtained using 5% (v/v) of glutaraldehyde solution and 0.03 M galactose; the total activity recovery coefficient (TARC) was 44.2%. The amount of immobilized enzyme was 12.49 mg with a total activity of 86.3 LAU at 37°C, using 5% (w/v) lactose solution in phosphate buffer (100 mM pH 6.9). The stability of the immobilized enzyme was approximately 585 fold higher in comparison with the stability of free enzyme. Multipoint covalent immobilization improves the stability of the enzyme, thereby enhancing the decision to use the membrane as a filtering element and support for the enzyme immobilization.