Removal of alkylphenols by the combined use of tyrosinase immobilized on ion‐exchange resins and chitosan beads

Abstract

Mushroom tyrosinase was covalently immobilized on a poly(acrylic acid)-type, weakly acidic cation-exchange resin (Daiaion WK10, Mitsubishi Chemical Corp., Tokyo, Japan) with 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride salt as a water-soluble carbodiimide. Ion-exchange resins immobilized with tyrosinase were packed in one column, and crosslinked chitosan beads prepared with epichlorohydrin were packed in another column. The enzymatic activity was modified by covalent immobilization, and the immobilized tyrosinase had a high activity in the temperature range of 30-45 C and in the pH range of 7-10. When solutions of various alkylphenols were circulated through the two columns packed with tyrosinase-immobilized ion-exchange resins and crosslinked chitosan beads at 45 C and pH 7 (the optimum conditions determined for p-cresol), alkylphenols were effectively removed through quinone oxidation with immobilized tyrosinase and subsequent quinone adsorption on chitosan beads. The use of chemically crosslinked chitosan beads in place of commercially available chitosan beads was effective in removing alkylphenols from aqueous solutions in shorter treatment times. The removal efficiency increased with an increase in the amount of crosslinked chitosan beads packed in the column because the rate of quinone adsorption became higher than the rate of enzymatic quinone generation. The activity of tyrosinase was iteratively used by covalent immobilization on ion-exchange resins. One of the most important findings obtained in this study is the fact that linear and branched alkylphenols suspected of weak endocrine-disrupting effects were effectively removed from aqueous solutions.

Biodegradation of bisphenols with immobilized laccase or tyrosinase on polyacrylonitrile beads

“…There are many studies on the application of phenoloxidases immobilized on porous glass beads (Marin-Zamora et al 2007), chitosan beads (D'Annibale et al 1999;Ispas et al 2010;Tamura et al 2010;Zhang et al 2008), polymeric membranes (Georgieva et al 2008;Lante et al 2000;Moeder et al 2004;Rasera et al 2009) and cross-linked as aggregates (CLEAs) or on silica nanoparticles (Cabana et al 2009;Galliker et al 2010). We also employed the immobilized laccase for the bioremediation of waters polluted by phenol compounds, such as cathecol (Durante et al 2004), syringic acid (Attanasio et al 2005), BPA (Diano et al 2007) and phthalates (Mita et al 2010).…”

Removal of Linear and Branched Alkylphenols with the Combined Use of Polyphenol Oxidase and Chitosan

“…Alternatively, so far, we have reported the removal of phenol compounds with oxidoreductases [17,18,19,20,21,22,23]. Peroxidases catalyze the conversion of phenol compounds into the corresponding phenoxy radicals in the presence of hydrogen peroxide (H 2 O 2 ).…”

Potential Use of Apple Polyphenol Oxidase for Bioremediation of Phenolic Contaminants

“…10,11 Researchers have found that the presence of different enzymes and isoenzymes along with other non-enzyme constituents in crude extract permits the extract to function under a wider range of conditions (pH, temperature, polyphenol concentration), and with more substrates than would be possible using single enzymes. 12 This study reports the possibility of using partially purified PPO from apple variety Idared for catechol removal from aqueous media. Catechol was chosen since it provokes changes in the function of erythrocytes at doses as low as 50 µg l −1 i.e.…”