Decolorization of dyes by a current-producing bacterium Shewanella marisflavi EP1 isolated from sea sediments

Abstract:

In this study, we investigated a new current-producing strain, Shewanella marisflavi EP1 isolated from costal sediments of Xiamen, its decolorization capability and mechanism of several types of dyes such as azo, anthraquinone and triphenyl methane. The results indicated that these dyes could be decolorized efficiently and the maximum capacity was 925 mg/(g cell dry weight?d) of Malachite Green. Strain EP1 could utilize various kinds of carbon sources, such as glucose, sucrose, xylose, lactate, formate and citrate for the decolorization of Xylidine Ponceau 2R. EP1 was active for decolorization in wide ranges of pH (6?10), temperture (16 °C?40 °C), and NaCl concentations (0?8%). The optimal conditions were pH 8.0, 30 °C, 1%?2% NaCl and lactate as carbon source, with a highest decolorization rate of 99.95% within 10 h. UV-vis absorption spectra demonstrated that the mechanism of the azo dye was degradation in the range of 0?8% NaCl.