کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1985803 1540235 2016 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Isolation, cloning and characterization of an azoreductase from the halophilic bacterium Halomonas elongata
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شیمی
پیش نمایش صفحه اول مقاله
Isolation, cloning and characterization of an azoreductase from the halophilic bacterium Halomonas elongata
چکیده انگلیسی

Azo dyes are a major class of colorants used in various industries including textile, paper and food. These dyes are regarded as pollutant since they are not readily reduced under aerobic conditions. Halomonas elongata, a halophilic bacterium, has the ability to decolorize different mono and di-azo dyes in anoxic conditions. In this study the putative azoreductase gene of H. elongata, formerly annotated as acp, was isolated, heterologously expressed in Escherichia coli, purified and characterized. The gene product, AzoH, was found to have a molecular mass of 22 kDa. The enzyme requires NADH, as an electron donor for its activity. The apparent Km was 63 μM for NADH and 12 μM for methyl red as a mono-azo dye substrate. The specific activity for methyl red was 0.27 μmol min−1 mg−1. The optimum enzyme activity was achieved in 50 mM sodium phosphate buffer at pH 6. Although increased salinity resulted in reduced activity, AzoH could decolorize azo dye at NaCl concentrations up to 15% (w/v). The enzyme was also shown to be able to decolorize remazol black B as a representative of di-azo dyes. This is the first report describing the sequence and activity of an azo-reducing enzyme from a halophilic bacterium.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: International Journal of Biological Macromolecules - Volume 85, April 2016, Pages 111–116
نویسندگان
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