title: Biodegradation of Direct Blue 15 by free and immobilized Trametes versicolor.
abstract: To investigate biodegradability by Trametes versicolor, five structurally different direct azo-dyes--Direct Black 38, Direct Blue 15 (DB 15), Direct Orange 26, Direct Green 6, and Direct Yellow 12--were studied. The DB 15 was determined as the best biodegradable dye by this white-rot fungus. Laccase and manganese peroxidase activities were monitored with the biodegradation process; it was observed that laccase played an important role in the dye degradation, while manganese peroxidase activity could not be detected. Possible degradation products also were examined by gas chromatography-mass spectrometry, but no metabolite was detected after the degradation and/or decolorization process. To enhance performance of the fungi during the degradation, Trametes versicolor cells were immobilized in alginate beads. Then, DB 15 decolorization by immobilized Trametes versicolor was studied in a small-scale packed-bed reactor. The color removal efficiency in repeated batches was found to be 98 and 93% for 50 mg/L DB 15.
authors.affiliation: Ege University, Faculty of Science, Biochemistry Department, Bornova-Izmir, Turkey.
authors.forename: Nurdan Kasikara
authors.initials: NK
authors.lastname: Pazarlioglu
authors.forename: Alper
authors.initials: A
authors.lastname: Akkaya
authors.forename: Hatice Ardag
authors.initials: HA
authors.lastname: Akdogan
authors.forename: Burcin
authors.initials: B
authors.lastname: Gungor
mesh_terms: D001391:Azo Compounds / Q000378:metabolism*; D001673:Biodegradation, Environmental; D008401:Gas Chromatography-Mass Spectrometry; D042845:Laccase / Q000378:metabolism; D010544:Peroxidases / Q000378:metabolism; D055454:Trametes / Q000201:enzymology / Q000378:metabolism*
chemical_list: D001391:Azo Compounds; C035549:direct blue 15; D042845:Laccase; D010544:Peroxidases; C051129:manganese peroxidase