Fifty yeast isolates from different habitats nearby a textile factory in Menoufia governerate, Egypt were screened for their ability to decolorize the azo dyes direct red 81 (DR81) and reactive brilliant red X-3B (RBR). Out of those, twenty two isolates displayed positive results therefore they were characterized morphologically and physiologically. The most active two were identified as Meyerozyma guilliermondii and Naganishia diffluens on the bases of 28S ribosomal RNA sequencing. The bio degradation of the dyes was confirmed by UV-visible spectra and IR analysis. The dyes decolorization percentage of and of DR81 and RBR reached and by these two yeasts respectively. Sucrose and glucose were the best carbon sources for the two yeasts whereas peptone was the best nitrogen source for both. | Biodegradation of the Azo dyes direct red 81 and reactive brilliant red X-3B by wild strains of yeasts meyerozyma guilliermondii and naganishia diffluens
