ABSTRACT
n-Octyl oleate was synthetized by enzymatic esterification reaction of oleic acid and n-octanol. Lipases from porcine pancreatic (PPL), Mucor javanicus (MJL), Candida sp. (CALA), Rhizomucor miehei (RML) and Thermomyces lanuginosus (TLL) were immobilized via interfacial activation on poly-methacrylate particles (PMA) and tested as biocatalysts. Their catalytic properties were determined in the hydrolysis of olive oil emulsion. Among them, TLL-PMA was the biocatalyst that yielded the highest hydrolytic activity (217.8±1.1 IU/g) and immobilized protein loading (37.5±0.4mg/g). This biocatalyst was also the most active in n-octyl oleate synthesis, thus selected for further studies. Maximum conversion percentage of 95.1±1.3% was observed after 60min of reaction at 45°C, 10% m/v of TLL-PMA, and molar ratio oleic acid:n-octanol of 1:1.5 in a solvent-free system. The biocatalyst fully retained its original activity after twelve cycles of reaction of 60min each. The product was confirmed by attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy analysis and their physico-chemical properties were determined according to ASTM standard methods. These results show that the immobilization of an alkalophilic and thermostable lipase (TLL) on PMA particles allowed the preparation of a highly active biocatalyst in hydrolysis and esterification reactions.
