Encapsulation of chloroperoxidase in novel hybrid polysaccharide-silica biocomposites: Catalytic efficiency, re-use and thermal stability

Chloroperoxidase was encapsulated into hybrid polysaccharide-silica matrices by means of sol-gel pro-cessing. Chitosan was found to be the most effective additive to improve enzyme catalytic performances.At the standard initial experimental conditions, enzyme was able to perform five complete reaction cyclesand a substrate conversion of 60% at the sixth cycle. The optimization of the procedure, which onsistedin the reduction of reaction time, the elimination of washes between cycles and the increase of the chi-tosan concentration in matrices, allowed a considerably higher reusability of the biocatalyst, up to 18consecutive reaction cycles.Moreover, immobilized enzyme displayed an excellent thermal stability and even at 70◦C its activityremained higher than 95% also after 2 h of incubation.These results paved the way to the application of chloroperoxidase for academic synthesis and indus-trial production of chemicals.