Horseradish Peroxidase-Carrying Electrospun Nonwoven Fabrics for the Treatment of o-Methoxyphenol

Chao Pan,Yucai Hu,Li Dong,Jing Wang,Ran Ding

doi:10.1155/2015/616879

Chao Pan, Yucai Hu + Show 3 more

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https://doi.org/10.1155/2015/616879

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Abstract

The carboxyl-functionalized polystyrene (poly(styrene-co-methacrylic acid), PSMAA) nanofibers with average diameters of 250 ± 20 nm was prepared by electrospinning. PSMAA nanofibrous membrane were employed for immobilization of horseradish peroxidase (HRP) enzyme on the fibrous surface by a chemical method. The parameters about immobilizing HRP on the PSMAA nanofibers were studied and the influence on the activity of the HRP is discussed. This study showed that soap-free emulsion method is an ideal technology to modify the polystyrene surface and ultimately achieve enzyme immobilization on electrospun PSMAA nanofibers surfaces. Compared with free HRP, the acid-base stability, thermal stability, and storage stability of HRP were increased after the immobilization. The immobilized HRP maintained about 60% of its initial activity during a 20-day storage period. However, the free HRP maintained only 40% of its initial activity. The removal percentages of o-methoxyphenol (OMP) reached 80.2% after 120 min for immobilized HRP. These results suggest that the proposed scheme for immobilization of HRP has potential in industrial applications for the treatment of phenolic wastewater.

Highlights

Horseradish peroxidase (HRP) has been shown to be able to remove a variety of phenols and aromatic amines from aqueous solutions [1,2,3]
At temperatures above 35∘C, as the temperature increased, the residual activity of the free HRP decreased faster than that of the immobilized HRP; that is, the immobilized HRP exhibited higher heat resistance than the free one. This is suggested to be due to interactions between enzyme and the poly(styrene-co-methacrylic acid) (PSMAA)-COOH supports that limited the enzyme movement to reduce the degree of freedom of the spatial structure of enzyme, protecting it from deactivation at high temperatures
Two spectra, the spectrum of the PSMAA membrane showed an absorbance band at 1698.97 cm−1, which is a characteristic band for carboxyl groups

Summary

Introduction

Horseradish peroxidase (HRP) has been shown to be able to remove a variety of phenols and aromatic amines from aqueous solutions [1,2,3]. The main drawback of treating wastewater by free HRP is its instability To overcome this shortcoming, immobilization of HRP has been developed as an effective method for the applications of HRP, since it offered many advantages, such as increasing the stability of HRP and being repeatedly used [4, 5]. The chemical modification of electrospun fibers has been shown to be an effective immobilization method compared with the physics modification. Groups on the MAA, were prepared by a combination of the soap-free emulsion polymerization method and an electrospinning technique (Scheme 1), which were employed as solid support to HRP enzyme, and immobilized HRP was used to remove OMP from water. The degradation efficiency of OMP by immobilized HRP was assessed

Experimental

Results and Discussion

Conclusion