Immobilization of β-galactosidase from Kluyveromyces lactis onto a polys iloxane-polyvinyl alcohol magnetic (mPOS-PVA) composite for lactose hydrolysis

beta-Galactosidase from Kluyveromyces lactis was covalently immobilized onto a mPOS-PVA, using glutaraldehyde as activating agent and its properties were evaluated, The enzymatic water insoluble derivative displayed the same optimum pH (6.5) and optimum temperature (50 degrees C) of the soluble enzyme. The apparent K-m(app) and activation energy for both soluble and immobilized enzyme derivative were found to be not significantly different. The mPOS-PVA beta-galactosiclase preparation presented a higher operational and thermal stability than the soluble enzyme. This immobilized beta-galactosidase also was effective in hydrolyzing lactose from milk. Hence, one can conclude that mPOS-PVA is an attractive and efficient support for p-galactosidase immobilization. (C) 2008 Elsevier B.V. All rights reserved.