Epoxy-silanization - tool for improvement of silica nanoparticles as support for lipase immobilization with respect to esterification activity

Abstract

BACKGROUND In this study, in order to obtain the best support for the immobilization of lipase from Candida rugosa (CRL), the procedure for chemical modification of fumed silica nanoparticles (FNS) with (3-Glycidyloxypropyl)trimethoxysilane (GOPTMS) was optimized by varying the amount of GOPTMS used and the duration of support modification. To evaluate the prospects of chemical modification of FNS surface on the immobilization process, the activity and thermal stability of lipase immobilized on GFNS was compared with lipase immobilized on FNS and cyanuric chloride functionalized amino silica (CCAFNS). RESULTS The epoxy functionalized silica nanoparticles (GFNS) with 400–500 µmol of introduced epoxy groups per g of support were the most efficient, since immobilized preparations in 1 mol L−1 buffer had the highest activity of approximately 1495 IU g−1 and a loading capacity of 294 mg g−1. Lipase immobilized on GFNS exhibited 1.5-fold higher hydrolytic activity and 2-fold higher esterification activity in the synthesis of aroma esters than lipase immobilized on CCAFNS, while its thermal stability was similar to CCAFNS preparations. CONCLUSION These results indicated that the type of modification of the FNS surface has an influence on the specificity of the immobilized lipase, since lipase immobilized on GFNS showed improved properties for ester synthesis which is a promising area for immobilized lipase application. © 2015 Society of Chemical Industry