Effects of Temperature and pH on Immobilized Laccase Activity in Conjugated Methacrylate-Acrylate Microspheres

Abstract EN

Immobilization of laccase on the functionalized methacrylate-acrylate copolymer microspheres was studied.

Poly(glycidyl methacrylate-co-n-butyl acrylate) microspheres consisting of epoxy groups were synthesized using facile emulsion photocuring technique.

The epoxy groups in poly(GMA-co-nBA) microspheres were then converted to amino groups.

Laccase immobilization is based on covalent binding via amino groups on the enzyme surface and aldehyde group on the microspheres.

The FTIR spectra showed peak at 1646 cm−1 assigned to the conformation of the polymerization that referred to GMA and nBA monomers, respectively.

After modification of the polymer, intensity of FTIR peaks assigned to the epoxy ring at 844 cm−1 and 904 cm−1 was decreased.

The results obtained from FTIR exhibit a good agreement with the epoxy content method.

The activity of laccase-immobilized microspheres increased upon increasing the epoxy content.

Furthermore, poly(GMA-co-nBA) microspheres revealed uniform size below 2 µm that contributes to large surface area of the microspheres to be used as a matrix, thus increasing the enzyme capacity and enzymatic reaction.

Immobilized enzyme also shifted to higher pH and temperature compared to free enzyme.