Using Electrochemical Methods To Study the Kinetics of Laccase-Catalyzed Oxidation of Phenols

Abstract

In the present work the laccase kinetics upon the oxidation process of phenolic compounds was studied using cyclic voltammetry (CV). Several hydroxybenzoic and cinnamic acid compounds were analyzed and the oxidation kinetics were correlated to their chemical structures. Significant differences were observed, and several structural parameters were identified as enhancers of the reaction rate. Folin-Ciocalteau, UV-Vis Spectrophotometry and Thin Layer Chromatography (TLC) methods were also used to assess the laccase-oxidation process. The TLC results correlated well with those from the CV, while the UV-Vis results do so with those from the Folin-Ciocalteau analysis. Results suggest that intermediate adducts, non-detectable by CV, Folin-Ciocalteau, UV-Vis, and TLC analyses, may be formed during the oxidation process. A new approach for using bare glassy carbon electrodes to detect phenolic compounds and monitor their oxidation using laccase enzymes is presented.

An Improved Method to Encapsulate Laccase from Trametes versicolor with Enhanced Stability and Catalytic Activity

“…Laccase can catalyze the oxidation of a variety of aromatic compounds (preferably phenolic compounds) [1,2] and has been widely employed for delignification, plant fiber derivatization, textile dye or stain bleaching, and contaminated water or soil detoxification [3][4][5][6]. However, the industrial applications of laccase are still seriously limited owing to their poor stability and high cost [7].…”

Fungal Laccase-Mediated Enhancement of the Bioactivity of Green Algae Extracts

“…UV-Vis absorption spectra of the main phenolic compounds before and after the enzymatic treatments were also recorded (Figures S6, S7). In all cases, typical UV absorbance peaks, attributed to the π-system of their aromatic rings were observed in the range of 200-400 nm [66,67]. The differentiation of peak positions in the UV-Vis spectra among the tested phenolic compounds is a result of their ionization state and the nature of the substituent [67].…”

“…New peaks in the 400-800 nm range were also observed due to the colored products formed [66]. Both laccases are unable to catalyze the oxidation of p-hydroxybenzoic acid and apigenin since the UV-Vis spectra of the reaction mixtures remain unchanged after the enzymatic treatment.…”

Removal of Bisphenol A Using Laccase‐Catalyzed Electrooxidation in the Presence of Humic Acid

“…[28,29] Therefore, laccase can be a great candidate for application in electrooxidation systems, e.g., biofuel cells, bioreactors, as well as bioremediation. [30][31][32] Besides, it has been applied sequentially after electrooxidation system to increase the organic pollutant removal efficiency. [30] Although electrooxidation could quickly mineralize many organic pollutants, its efficiency might be reduced under real-life conditions due to low conductive environments.…”