Efficacy of amphiphile-modified laccase in enzymatic oxidation and removal of phenolics in aqueous solution

This study is mainly related to the characterization of a chemically modified laccase from the Trametes sp. for use in the oxidation and the removal of phenolics in aqueous systems. An amphiphilic copolymer, polyalkyleneoxide-co-maleic anhydride was used as a modifier. The amphiphile-modified laccase displayed higher catalytic activity along with improved thermal stability in the oxidation reaction of 2,6-dimethoxyphenol. The chemical modification resulted in a 20- to 10-fold increase in thermal stability at 25 and 40degreesC, respectively. The modified laccase was applied to remove a range of phenolic compounds including mono-, di-, and tri-chlorophenols, cresol, and xylenol, all of which usually behave as hazardous pollutants of natural environments. The modified laccase exhibited a remarkably improved efficiency over that of the native laccase in terms of removing various phenolic substances. These results revealed that the enzymatic oxidation by the amphiphile-modified laccase is suitable for the efficient removal of phenolics in aqueous systems. (C) 2004 Elsevier Inc. All rights reserved.