DECHLORINATION OF 2,4,6-TRICHLOROPHENOL BY FREE AND IMMOBILIZED LACCASE FROM TRAMETES VERSICOLOR IN A LAB SCALE BIOREACTOR Arzu üNAL, Ahmet ABUK, Nazif KOLONKAYA

Detoxification of a chlorinated phenolic compound, 2,4,6- trichlorophenol through treatment with laccase enzyme produced by a white rot fungus, Trametes versicolor was investigated. Enzymaticdechlorination experiments by using free and immobilized laccase have been performed in a lab scale bioreactor. Chlorine ion and dissolved oxygen electrodes mounted to the bioreactor were used continuouslyto detect the profiles of chlorine ions and oxygen consumption, respectively, in reaction medium. The maximum dechlorination activity of laccase for free and immobilized form was determined as 160 μM of substrate concentration at pH 5.0, 25 °C, and 30 min of incubation time. Also, GC/MS analyses of enzymatic degradation products indicated that chlorine removal was a result of degradation of 2,4,6- trichlorophenol by the laccase under the determined optimum conditions.