Biochemical characteristics of a textile dye degrading extracellular laccase from a Bacillus sp. ADR
2010; Elsevier BV; Volume: 102; Issue: 2 Linguagem: Inglês
10.1016/j.biortech.2010.08.086
ISSN1873-2976
AutoresAmar A. Telke, Gajanan S. Ghodake, Dayanand C. Kalyani, Rhishikesh S. Dhanve, Sanjay P. Govindwar,
Tópico(s)Microbial Metabolism and Applications
ResumoBacillus sp. ADR secretes an extracellular laccase in nutrient broth, and this enzyme was purified up to 56-fold using acetone precipitation and DEAE-cellulose anion exchange chromatography. The molecular weight of purified laccase was estimated to be 66 kDa using sodium dodecyl sulfate polyacrylamide gel electrophoresis. The purified laccase oxidized 2,6-dimethoxy phenol, o-tolidine, hydroquinone, L-DOPA and guaiacol. The optimum pH for oxidation of o-tolidine, 2,6-dimethoxy phenol and guaiacol were 3.0, 4.0 and 5.0, respectively. The purified laccase contained 2.7 mol/mol of copper. The laccase was stable up to 40 °C and within the pH range of 7.0-9.0. Well-known inhibitors of multicopper oxidases such as, sodium azide, L-cysteine and dithiothreitol showed significant inhibition of laccase activity. The purified enzyme decolorized structurally different azo dyes with variable decolorization rates and efficiencies of 68-90%. This study is useful for understanding the precise use of Bacillus sp. ADR in the decolorization of textile dyes containing industrial wastewater.
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