Screening trials for the encapsulation of laccase enzymatic extract in silica sol-gel.

The effects of selected process conditions for the sol-gel encapsulation of laccase enzymatic extract, obtained from <italic>Coriolus hirsutus</italic>, were investigated. Screening trials were carried out to identify the parameters having the most pertinent effects on the encapsulation efficiency (EE) and the residual laccase activity. These parameters included water/silane molar ratio (<italic>r</italic>), HCl content and protein loading, for the pre-gel silica sol as well as the required time for gel drying and for aging, for the sol-gel process. The experimental findings indicated that a sol-gel drying time of over 6 h resulted in a complete loss of laccase catalytic activity, while an increase in the gel aging time led to an enhancement of the residual enzyme activity. Except for <italic>r</italic>, the investigated parameters demonstrated no significant effect on the EE of the sol-gel encapsulated enzymatic extract. Overall, the encapsulation of laccase extract in the sol-gel matrix resulted in an enhancement of its catalytic activity, where its highest residual activity (349%) was obtained with an <italic>r</italic>-value of 4, an HCl content of 4 µmol and a protein loading of 1 mg/mL, using 6 and 24 h of drying and aging times, respectively.<graphic></graphic> [ABSTRACT FROM AUTHOR]