Immobilization of Horseradish Peroxidase for Phenol Degradation

The use of enzymes to degrade environmental pollutantshas receivedwide attention as an emerging green approach. Horseradish peroxidase(HRP) can efficiently catalyze the degradation of phenol in the environment;however, free HRP exhibits poor stability and temperature sensitivityand is easily deactivated, which limit its practical applications.In this study, to improve their thermal stability, HRP enzymes wereimmobilized on mesoporous molecular sieves (Al-MCM-41). Specifically,Al-MCM-41(W) and Al-MCM-41(H) were prepared by modifying the mesoporousmolecular sieve Al-MCM-41 with glutaraldehyde and epichlorohydrin,respectively, and used as carriers to immobilize HRP on their surface,by covalent linkage, to form the immobilized enzymes HRP@Al-MCM-41(W)and HRP@Al-MCM-41(H). Notably, the maximum reaction rate of HRP@Al-MCM-41(H)was increased from 2.886 x 10(5) (free enzyme) to 5.896x 10(5) U/min(-1), and its half-lifeat 50 & DEG;C was increased from 745.17 to 1968.02 min; the thermalstability of the immobilized enzyme was also significantly improved.In addition, we elucidated the mechanism of phenol degradation byHRP, which provides a basis for the application of this enzyme tophenol degradation.