Study of different supports and activation protocols for Beta-galactosidase from Kluyveromyces lactis immobilization

BEZERRA, CAMILLA; DE SOUZA, MARIA CRISTIANE; DE FREITAS, WENDEBERTO; MAMMARELLA, ENRIQUE; GONÇALVES, LUCIANA; ADRIANO, WELLINGTON

Buzios

Congreso; XIX Congresso Brasileiro de Engenharia Quimica; 2012

Associação Brasileira de Engenharia Química e Universidades UFRJ, UERJ, UFRRJ e UFF

Chitosan, cashew bagasse and coconut husks are raw materials found in northeastern Brazil as industrial waste presenting low cost and used as alternative supports for enzymes immobilization. β-galactosidase from Kluyveromyces lactis, EC (3.2.1.23) has received a particular interest because it can be used to produce a molecular mixture of glucose and galactose from lactose. This work aims studying activation methods supports for β-galactosidase immobilization. Glutaraldehyde activation was carried out by two ways. Support was added to glutaraldehyde 5% v/v for 30 min, pH 7.0 (GLU1) or it was added to KOH 0.5 mol.L-1 for 30 min followed by dialdehyde addiction until 0.8% v/v for 30 min at 50°C (GLU2). The same was done with epichlorohydrin (EPI) or glycidol (GLY). However, it was performed an activation by using glycidol (DFGLY) or epichlorohydrin (DFEPI) with previous support treatment using dimethylformamide and 0.1 mol.L-1 KOH during 18h. Enzyme activity was measured using lactose 5% m/v as substrate and glucose concentration determined by GOD-PAP method. Offered enzyme loading in potassium phosphate buffer pH 7.0 with MgCl2 and MnCl2 was added to the activated support at 25°C for 3h. Some of derivatives showed 100% of immobilization yield (IY). Best derivative was chitosan GLU2 with 100% and 19.2% of recovered activity. According to this work, use of chitosan for β-galactosidase immobilization becomes an attractive alternative for lactose hydrolysis at dairy industry.