This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Tauber, M. M.
Right arrow Articles by Rehorek, A.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Tauber, M. M.
Right arrow Articles by Rehorek, A.
Agricola
Right arrow Articles by Tauber, M. M.
Right arrow Articles by Rehorek, A.

 Previous Article  |  Next Article 

Applied and Environmental Microbiology, May 2005, p. 2600-2607, Vol. 71, No. 5
0099-2240/05/$08.00+0     doi:10.1128/AEM.71.5.2600-2607.2005
Copyright © 2005, American Society for Microbiology. All Rights Reserved.

Degradation of Azo Dyes by Laccase and Ultrasound Treatment

Michael M. Tauber,1,2 Georg M. Guebitz,2 and Astrid Rehorek1*

University of Applied Sciences Cologne, Chemical Engineering and Plant Design, Betzdorfer Strasse 2, D-50679 Cologne, Germany,1 Graz University of Technology, Institute for Environmental Biotechnology, Petersgasse 12, A-8010 Graz, Austria2

Received 13 June 2004/ Accepted 21 November 2004

The goal of this work was to investigate the decomposition of azo dyes by oxidative methods, such as laccase and ultrasound treatments. Each of these methods has strong and feeble sides. The laccase treatment showed high decolorization rates but cannot degrade all investigated dyes (reactive dyes), and high anionic strength led to enzyme deactivation. Ultrasound treatment can decolorize all tested dyes after 3 h at a high energy input, and prolonged sonication leads to nontoxic ionic species, which was demonstrated by ion chromatography and toxicity assays. For the first time, it was shown that a combination of laccase and ultrasound treatments can have synergistic effects, which was shown by higher degradation rates. Bulk light absorption and ion-pairing high-performance liquid chromatography (IP-HPLC) were used for process monitoring, while with reversed-phase HPLC, a lower number of intermediates than expected by IP-HPLC was found. Liquid chromatography-mass spectrometry indicated that both acid orange dyes lead to a common end product due to laccase treatment. Acid Orange 52 is demethylated by laccase and ultrasound treatment. Further results confirmed that the main effect of ultrasound is based on ·OH attack on the dye molecules.


* Corresponding author. Mailing address: University of Applied Sciences Cologne, Faculty of Process Engineering, Energy and Mechanical Systems, Institute of Chemical Engineering and Plant Design, Betzdorfer Strasse 2, D-50679 Cologne, Germany. Phone: 49 221 8275 2234. Fax: 49 221 8275 2202. E-mail: astrid.rehorek{at}fh-koeln.de.


Applied and Environmental Microbiology, May 2005, p. 2600-2607, Vol. 71, No. 5
0099-2240/05/$08.00+0     doi:10.1128/AEM.71.5.2600-2607.2005
Copyright © 2005, American Society for Microbiology. All Rights Reserved.




This article has been cited by other articles:

  • Zille, A., Gornacka, B., Rehorek, A., Cavaco-Paulo, A. (2005). Degradation of Azo Dyes by Trametes villosa Laccase over Long Periods of Oxidative Conditions. Appl. Environ. Microbiol. 71: 6711-6718 [Abstract] [Full Text]