DECOLORIZATION OF AZO DYES BY PURPLE NON-SULFUR BACTERIA

Purple non-sulfur bacterial isolates from different water resources have shown decolorizing activity on different azo dyes.Five isolates of different purple nonsulfur bacterial species, i.e.Rhodobacter adriaticus, R. blasticus, R. capsulatus, Rhodovulum strictum, Rhodopseudomonas palustris) could decolorize up to 96% of tested dyes after two days of illuminated and anaerobic incubation.The decolorizing activity varied by the phototrophic isolates and by the dye substrates.Although phototrophic bacteria have been known to be able to metabolize N-heterocyclic compounds, this is the first report on the metabolizing activity of these bacteria on azo dyes.