Activation of lignin peroxidase in organic media by reversed micelles

Abstract

Activation of lignin peroxidase (LIP) in an organic solvent by reversed micelles was investigated. Bis(2-ethylhexyl)sulfosuccinate sodium salt (AOT) was used as a surfactant to form a reversed micelle. Lyophilized LIP from an optimized aqueous solution exhibited no enzymatic activity in any organic solvents examined in this study; however, LIP was catalytically active by being entrapped in the AOT reversed micellar solution. LIP activity in the reversed micelle was enhanced by optimizing either the preparation or the operation conditions, such as water content and pH in water pools of the reversed micelle and the reaction temperature. Stable activity was obtained in isooctane because of the stability of the reversed micelle. The optimal pH was 5 in the reversed micellar system, which shifted from pH 3 in the aqueous solution. The degradation reaction of several environmental pollutants was attempted using LIP hosted in the AOT reversed micelle. Degradation achieved after a 1-h reaction reached 81%, 50%, and 22% for p-nonylphenol, bisphenol A, and 2,4-dichlorophenol, respectively. This is the first report on the utilization of LIP in organic media.

Degradation of Polycyclic Aromatic Hydrocarbons (PAHs) by Laccase in Rhamnolipid Reversed Micellar System

“…However, beyond the RL concentration of 0.065 mM for anthracene, and beyond the RL concentration of 0.075 mM for pyrene, the degradation rates decreased. The viscosity of the reversed micelle solution drastically increased when RL concentration increased [19]. This may result in lowering the exchange rate of water molecules of laccase and PAH molecules in reversed micelles, which instantly causes a decrease in degradation rates at a higher surfactant concentration.…”

“…The Wo value defined by [H 2 O]/[surfactant] was used as the indicator of water content in the reversed micelles [19]. The Wo value has also been known to correlate linearly with the size of the reversed micelles [20].…”

Kinetic Studies on the Lignin Peroxidase Catalyzed Oxidation of Veratryl Alcohol by H2O2 in AOT/Isooctane/Toluene/Water Reverse Micelles

“…[4][5][6][7] Since many of these aromatic pollutants are poorly soluble in water, an attempt was made to degrade these hydrophobic compounds in a reverse micellar medium. [8][9][10] To understand the microheterogeneous and interfacial effects of the reverse micellar medium on the LiP catalyzed degradation reaction, the catalytic and kinetic properties of LiP hosted in the reverse micelles should be studied. Veratryl alcohol (VA), a secondary metabolite of Phanerochaete chrysosporium, is a psychological substrate of LiP.…”

Mechanistic studies on the effect of veratryl alcohol on the lignin peroxidase catalyzed oxidation of pyrogallol red in reversed micelles

“…In reversed micellar medium the degradation efficiency could be greatly improved due to high substrate concentration and high enzyme dispersion. Studies on the catalytic performance of LiP in reversed micellar medium have been reported [20,21]. Recently we have found that LiP exhibits high activity in a mixed reversed micellar system-bis (2-ethylhexyl) sulfosuccinate sodium (AOT)/polyoxyethylene lauryl ether (Brij30) mixed reversed micelles [22].…”