title: Laccase-mediated oxidative degradation of the herbicide dymron.
abstract: The present study reports the successful and effective degradation of the persistent herbicide dymron catalyzed by the oxidative enzyme laccase in the presence of a reaction mediator (a laccase/mediator system). Using 2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) as the mediator, over 90% of dymron was degraded within 24 h, while the half-life of dymron is 50 days in soil. The results suggested that oxidation of dymron resulted in the production of decomposed compounds with a single aromatic ring. We also found that edible surfactants and a dishwashing detergent were useful to solubilize dymron in an aqueous solution and did not inhibit the oxidative degradation. Degradation proceeded at acidic pH and in a broad range of temperatures (303-353 K). The use of natural mediators also allowed the oxidative degradation of dymron to some extent. In conclusion, we propose the possible use of a laccase/mediator system for the treatment of soils and drainwater contaminated with herbicides.
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering and Center for Future Chemistry, Kyushu University, 744 Moto-oka, Fukuoka 819-0395, Japan.
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Maruyama
authors.forename: Chiho
authors.initials: C
authors.lastname: Komatsu
authors.forename: Junji
authors.initials: J
authors.lastname: Michizoe
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Ichinose
authors.forename: Masahiro
authors.initials: M
authors.lastname: Goto
mesh_terms: D052160:Benzothiazoles; D008401:Gas Chromatography-Mass Spectrometry; D006540:Herbicides / Q000737:chemistry / Q000378:metabolism*; D042845:Laccase / Q000378:metabolism*; D015394:Molecular Structure; D010084:Oxidation-Reduction; D010671:Phenylurea Compounds / Q000737:chemistry / Q000378:metabolism*; D012995:Solubility; D013451:Sulfonic Acids / Q000737:chemistry / Q000378:metabolism; D013501:Surface-Active Agents
chemical_list: C492368:1-(alpha,apha-dimethylbenzyl)-3-(4-methylphenyl)urea; D052160:Benzothiazoles; D006540:Herbicides; D010671:Phenylurea Compounds; D013451:Sulfonic Acids; D013501:Surface-Active Agents; C002502:2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid; D042845:Laccase