IMPROVING THE CATALYTIC FEATURES OF THE LIPASE FROM Rhizomucor miehei IMMOBILIZED ON CHITOSAN-BASED HYBRID MATRICES BY ALTERING THE CHEMICAL ACTIVATION CONDITIONS

The lipase from Rhizomucor miehei (RML) has been immobilized on chitosan-based hybrid (sodium alginate or carrageenan) matrices activated with glycidol (GLY), epichlorohydrin (EPI) or glutaraldehyde (GLU) groups. Then, the properties of the different biocatalysts have been evaluated and compared with the soluble RML. Thermal stability (at pH 7.0 and 60 °C) was significantly increased when compared to the soluble enzyme: 154-fold for chitosan 5.0% - GLU, 80-fold for chitosan 2.5% - carrageenan 2.5% - GLY and 93-fold for chitosan 2.5% - alginate 2.5% - EPI. The best biocatalyst preparation, which was 154-fold more stable than the soluble enzyme, was obtained when RML was immobilized on chitosan activated with glutaraldehyde 5.0% v/v. According to the results, it was concluded that RML immobilization on chitosan-based hybrid matrices using different chemistries greatly produced biocatalysts with different properties.