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Indexed by:期刊论文

Date of Publication:2013-09-01

Journal:APPLIED MICROBIOLOGY AND BIOTECHNOLOGY

Included Journals:SCIE、EI、PubMed、Scopus

Volume:97

Issue:17

Page Number:7935-7942

ISSN No.:0175-7598

Key Words:Azo dye; Decolorization; Humic acid; Lawsone; Geobacter metallireducens

Abstract:Geobacter metallireducens was found to be capable of decolorizing several azo dyes with different structures to various extents. Pyruvate, ethanol, acetate, propionate, and benzoate could support 66.3 +/- 2.6-93.7 +/- 2.1 % decolorization of 0.1 mM acid red 27 (AR27) in 40 h. The dependence of the specific decolorization rate on AR27 concentration (25 to 800 mu M) followed Michaelis-Menten kinetics (K (m) = 186.9 +/- 1.4 mu Ie, V (max) = 0.65 +/- 0.02 mu mol mg protein(-1) h(-1)). Enhanced AR27 decolorization was observed with the increase of cell concentrations ranging from 7.5 to 45 mgL(-1). AR27 decolorization by G. metallireducens was retarded by the presence of goethite, which competed electrons with AR27 and was reduced to Fe(II). The addition of low concentrations of humic acid (1-100 mgL(-1)) or 2-hydroxy-1,4-naphthoquinone (0.5-50 mu M) could improve the decolorization performance of G. metallireducens. High-performance liquid chromatography analysis suggested reductive pathway to be responsible for decolorization. This was the first study on azo dye decolorization by Geobacter strain and might improve our understanding of natural attenuation and bioremediation of environments polluted by azo dyes.