Abstract
In this study, two different types of enzyme immobilization methods which were physical adsorptions (PA), and covalent bonding of cross-linked enzyme aggregates (CLEA) were used for laccase to immobilize onto raw polysulfone (PSF) and polysulfone/sepiolite (PSF/SEP) nanocomposites. After the preliminary study, a strategy for screening and optimization of laccase immobilization on PSF/SEP was then further developed by using a two-level factorial design and Box-Behnken design (BBD), respectively. Laccase (Lac) concentration, glutaraldehyde (Gla) concentration, pH values, adsorption (PA) time, PA temperature, CLEA time, and CLEA temperature were chosen in this study as important variables which they will influence the immobilization yield. It was found that Lac concentration, PA time, and Gla concentration are significant variables for the immobilization yield of Lac on PSF/SEP in the screening process. The highest immobilization yield was 75 % at 0.10 mg/mL Lac concentration, 2 h PA time, and 0.20 (v/v) % Gla concentrations, with an increase of 46.57 % over the immobilization yield before optimization.
