DIMENSIONING OF VINYLSULFONIC SUPPORTS FROM CASHEW APPLE BAGASSE BIOMASS IN THE IMMOBILIZATION OF LIPASES

Abstract

In this work, the support, cashew apple bagasse (CAB), was chemically modified with divinyl sulfone (DVS), and it was evaluated to immobilize Candida antarctica lipase A (CAL-A). The best activation conditions of CAB support were defined by an advanced experimental design using the Taguchi method, assessing five factors at four levels (concentration of DVS, ionic strength, pH, temperature, and time). The support and biocatalyst (CAB-DVS-CAL-A) were characterized by Fourier transform infrared spectroscopy (FTIR), elemental analysis, thermogravimetry (TGA), scanning microscopy (SEM), fluorescence spectroscopy (XRF) and electrophoresis. The optimal conditions to activate the support were DVS concentration of 1.4 mol L-1 (3 mL of DVS in 20 mL of reaction volume), a concentration of sodium bicarbonate buffer at 5 mmol L-1, pH 3.0 at 30 °C for 12 h. The immobilization on CAB-DVS promoted increased thermal stability at 70 °C and different pHs of CAL-A. Therefore, the selected conditions allowed for a catalyst with a catalytic activity of 6.8 U g-1 and more stable than the free enzyme (CAL-A). This demonstrates that pretreated and DVS-activated CAB is a promising support for enzyme immobilization.