The optimization of synthesis conditions for laccase entrapment in mesoporous silica microparticles by response surface methodology

This study investigated the optimization of in-situ laccase entrapment in mesoporous silica microparticles. The response surface methodology (RSM) based on a 3-level-4-factor Box-Behnken experimental design was employed to establish the relationships among the independent synthesis variables (ISV) as well as to search for an optimal synthesis condition for laccase entrapped mesoporous silica microparticles (LSM). The ISV comprise of H2O/TEOS molar ratio (H2O/TEOS), hydrochloric acid loading (HCl), triethylamine loading (TEA), and laccase loading (Lac) were evaluated towards the specific laccase catalytic activity (A(s)) response as the dependent variable. The optimization results show that the optimal ISV obtained were (H2O/TEOS) = 5.44, (HCl) = 2.52 x 10(-6) mol, (TEA) = 0.39 x 10(-3) mol and (Lac) = 3.83 mg/ml having the predicted and observed A(s) of 301.7 and 298.36 U/g, respectively. A moderate degree of correlation between the A(s) response and ISV was as well obtained by the determination coefficient (R-2) value of 0.89. These results demonstrated the applicability of RSM for the optimization of ISV in LSM synthesis. It was found that the LSM has a good reusability that holds potential industrial applications, even though it encounters the mass transfer kinetic limitations. (C) 2015 Elsevier Inc. All rights reserved.