Biodegradation of diazo dye Evans blue by four strains of Streptomyces isolated from soils of Algeria

As part of the development of an ecological solution to eliminate azo dyes present in the effluents of textile factories, we have isolated from different soils four Streptomyces strains with high degra-dation potential against Evans blue (EB). These strains affiliated to Streptomyces maritimus, S. mu-tabilis, S. ardesiacus and S. sp can also degrade other azo dyes such as Amido black 10B, Chlorazol black E, Congo red, Methyl red and Nigrosine. Study of the effects of incubation time, tempera-ture, pH and addition of small amounts of carbohydrates on the degradation potential of strains allowed reaching an elimination rate of up to 97% of the initial Evans blue concentration (50 mg/ l). Furthermore, the degradation potential of strains was only slightly affected by high concentra-tions of EB, salinity and the presence of some metal ions in the culture medium.