Magnetic CLEAs of ?-Galactosidase from Aspergillus oryzae as a Potential Biocatalyst to Produce Tagatose from Lactose

?-galactosidase is an enzyme capable of hydrolysing lactose, used in various branches industry, mainly the food industry. As efficient industrial use enzymes depends on their reuse, it necessary to find effective method for immobilisation, maintaining high activity and stability. The present work proposes cross-linked magnetic aggregates (mCLEAs) prepare heterogeneous biocatalysts ?-galactosidase. Different concentrations glutaraldehyde (0.6%, 1.0%, 1.5%), as a cross-linking agent, were studied. dextran-aldehyde alternative agent was also evaluated. mCLEAs presented increased recovered directly related concentration glutaraldehyde. Modifications protocol with glutaraldehyde, adding competitive inhibitor or polymer coating, have not been increasing its thermal biocatalyst prepared using 73.6% activity, aside from substrate affinity equivalent free enzyme. stability at 60 °C higher (mCLEA-GLU-1.5) than one produced (mCLEA-DEX), opposite happened 50 °C. Results obtained lactose hydrolysis, product produce rare sugar (D-tagatose) operational storage indicate that adequate characteristics use.