OrderedMesoporous Silica Matrix for Immobilizationof Chloroperoxidase with Enhanced Biocatalytic Performance for OxidativeDecolorization of Azo Dye.

Mesoporoussilica material was prepared to immobilize chloroperoxidase(CPO) from Caldariomyces fumagointhis work. The mesoporous material (FDU-12-140) with 15–18nm pore entrances was found to be a very suitable support not onlybecause it allowed the entry of only a few CPO molecules (diameteraround 6.2 nm) so as to avoid the aggregation of enzyme moleculesthat may result in a decline in its apparent activity, but also becauseit provided enough flip space for the enzyme during its catalyticaction. Enzymatic oxidative decolorization of Crocein Orange G wasemployed to evaluate the catalytic performance of CPO. The decolorizationefficiency of dye by immobilized CPO reached 90% within 70 min. Moreover,it displayed improved thermostability and maintained higher activityin organic solvents compared to that of free enzyme. When incubatedat 80 °C for 1 h, 42% of the activity of immobilized enzyme wasreserved compared with that at 20 °C, whereas free CPO maintainedonly 8.5%. Even in the most hydrophilic N,N-dimethylformamide(log p= −1.0), the decolorizationefficiency remained30% by immobilized CPO, but no decolorization was observed by freeCPO at the same conditions. The relative activity of immobilized CPOin the 20th reuse maintained 61% of that in the first run in decolorizationof the dye. [ABSTRACT FROM AUTHOR]