title: Synergistic action of azoreductase and laccase leads to maximal decolourization and detoxification of model dye-containing wastewaters.
abstract: The azoreductase PpAzoR from Pseudomonas putida shows a broader specificity for decolourization of azo dyes than CotA-laccase from Bacillus subtilis. However, the final products of PpAzoR activity exhibited in most cases a 2 to 3-fold higher toxicity than intact dyes themselves. We show that addition of CotA-laccase to PpAzoR reaction mixtures lead to a significant drop in the final toxicity. A sequential enzymatic process was validated through the use of 18 representative azo dyes and three model wastewaters that mimic real dye-containing effluents. A heterologous Escherichia coli strain was successfully constructed co-expressing the genes coding for both PpAzoR and CotA. Whole-cell assays of recombinant strain for the treatment of model dye wastewater resulted in decolourization levels above 80% and detoxification levels up to 50%. The high attributes of this strain, make it a promising candidate for the biological treatment of industrial dye containing effluents.
authors: Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal.
authors: Sónia
authors: S
authors: Mendes
authors: Ana
authors: A
authors: Farinha
authors: Christian G
authors: CG
authors: Ramos
authors: Jorge H
authors: JH
authors: Leitão
authors: Cristina A
authors: CA
authors: Viegas
authors: Lígia O
authors: LO
authors: Martins
mesh_terms: D000818:Animals; D001391:Azo Compounds / Q000302:isolation & purification / Q000633:toxicity; D001412:Bacillus subtilis / Q000201:enzymology / Q000235:genetics; D001673:Biodegradation, Environmental / Q000187:drug effects; D017173:Caenorhabditis elegans / Q000187:drug effects / Q000502:physiology; D003116:Color; D004396:Coloring Agents / Q000302:isolation & purification* / Q000633:toxicity; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D005798:Genes, Bacterial / Q000235:genetics; D008658:Inactivation, Metabolic; D042845:Laccase / Q000235:genetics / Q000378:metabolism*; D008956:Models, Chemical; D009247:NADH, NADPH Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D009601:Nitroreductases; D010084:Oxidation-Reduction / Q000187:drug effects; D016958:Pseudomonas putida / Q000201:enzymology / Q000235:genetics; D012098:Reproduction / Q000187:drug effects; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000254:growth & development; D018675:Toxicity Tests; D014865:Waste Disposal, Fluid; D018508:Water Purification / Q000379:methods*
chemical_list: D001391:Azo Compounds; D004396:Coloring Agents; D042845:Laccase; D009247:NADH, NADPH Oxidoreductases; D009601:Nitroreductases; C021106:azoreductase