title: Contributions to a better comprehension of redox-mediated decolouration and detoxification of azo dyes by a laccase produced by Streptomyces cyaneus CECT 3335.
abstract: The ability of a laccase (EC 1.10.3.2) produced by Streptomyces cyaneus CECT 3335 to decolourise and detoxify azo dyes was assessed. Results showed that a colour loss of 90% was achieved only in the presence of acetosyringone (0.1mM) acting as a redox mediator for the laccase. Toxicological analysis of the decolourised dyes revealed that there was no direct correlation between decolouration and detoxification; in fact, in the case of the dyes Methyl Orange and Orange II, a significant increase in toxicity was produced after the treatment. In contrast, a significant decrease in toxicity was observed after the decolouration of New Coccine and Chromotrope 2R. Finally, HPLC analysis of the dyes after treatment revealed the complete disappearance of both dyes and mediator and a concomitant appearance of new chromatographic peaks which could be responsible of the residual toxicity detected in some cases.
authors.affiliation: Departamento de Microbiología y Parasitología, Universidad de Alcalá, Ctra. Madrid-Barcelona, Madrid, Spain.
authors.forename: Raquel
authors.initials: R
authors.lastname: Moya
authors.forename: Manuel
authors.initials: M
authors.lastname: Hernández
authors.forename: Ana B
authors.initials: AB
authors.lastname: García-Martín
authors.forename: Andrew S
authors.initials: AS
authors.lastname: Ball
authors.forename: M Enriqueta
authors.initials: ME
authors.lastname: Arias
mesh_terms: D001391:Azo Compounds / Q000378:metabolism* / Q000633:toxicity; D001673:Biodegradation, Environmental / Q000187:drug effects; D002851:Chromatography, High Pressure Liquid; D003116:Color; D004396:Coloring Agents / Q000378:metabolism* / Q000633:toxicity; D006863:Hydrogen-Ion Concentration / Q000187:drug effects; D008658:Inactivation, Metabolic; D042845:Laccase / Q000302:isolation & purification / Q000378:metabolism*; D010084:Oxidation-Reduction / Q000187:drug effects; D013053:Spectrophotometry; D013302:Streptomyces / Q000187:drug effects / Q000201:enzymology*; D013784:Textiles
chemical_list: D001391:Azo Compounds; D004396:Coloring Agents; D042845:Laccase