Degradation of anthracene by laccase of Trametes versicolor in the presence of different mediator compounds.
Laccase of Trametes versicolor was generally able to oxidize anthracene in vitro. After 72 h incubation about 35% of the anthracene was transformed stoichiometrically to 9,10-anthraquinone. Transformation of anthracene increased rapidly in the presence of different mediators that readily generate stable radicals: 2,2'-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) and 1-hydroxybenzotriazole. For the reaction, the presence of both the laccase and the mediator was necessary. In the presence of 0.005 mM 1-hydroxybenzotriazole this conversion had removed 47% of the anthracene after 72 h; 75% of the substrate was oxidized during this period when ABTS (1 mM) was used as mediator. In contrast to reactions without or with only low concentrations of a mediator, there was a discrepancy between the disappearance of anthracene and the formation of 9,10-anthraquinone in mediator-forced reactions. Coupling-products of mediators with anthracene degradation products were found. Anthracene disappeared nearly completely after incubation for 72 h with laccase in a 0.1 mM solution of 1-hydroxybenzotriazole and was transformed to 9,10-anthraquinone in about 80% yield; 90% of the substrate was transformed in the presence of ABTS (2.0 mM) resulting again in 80% quinone. Phenothiazine was not effective in this system.
Johannes
C
C
Institute of Forest Botany, University of Göttingen, Germany.
Majcherczyk
A
A
Hüttermann
A
A
D000873:Anthracenes / Q000378:metabolism*; D000880:Anthraquinones / Q000378:metabolism; D052160:Benzothiazoles; D001673:Biodegradation, Environmental / Q000187:drug effects; D001709:Biotechnology; D005609:Free Radicals / Q000378:metabolism; D042845:Laccase; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000378:metabolism*; D011124:Polyporaceae / Q000201:enzymology*; D013451:Sulfonic Acids / Q000494:pharmacology; D014230:Triazoles / Q000494:pharmacology
D000873:Anthracenes; D000880:Anthraquinones; D052160:Benzothiazoles; D005609:Free Radicals; D013451:Sulfonic Acids; D014230:Triazoles; C042834:9,10-anthraquinone; C002502:2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid; C011852:1-hydroxybenzotriazole; D010088:Oxidoreductases; D042845:Laccase; C034020:anthracene