Aims: The aim of the present study was to isolate yeasts with the high ability of decolorization to use as biosorption in removing azo dyes.
Materials and Methods: In this experimental study, an enrichment method was used to isolate dye absorbent yeast in a salt medium. The dye absorption was performed with comparing wet and dried biomass. Decolorization level was evaluated in different concentrations of dye and salt. By molecular method, the best strain was identified and its ability to absorb various dyes as well as mono-, di-, and tri-azo dyes were investigated. Statistical tests including one way ANOVA and Tukey as well as SPSS 19 software were used.
Findings: Among 17 yeast isolates, ADH17 was selected as the most capable isolate. This isolate was 100% similar to Sarocladium sp. Dried biomass could adsorb the dye 4 times more than the wet biomass. The remained dye increased when initial dye concentration rose, but different concentrations of sodium chloride had no significant effect in biosorption. This strain could adsorb a broad range of azo dyes, including mono-, di-, and tri- azo and acidic, basic, and reactive dyes as well. The highest biosorption was 97.43% for reactive red and the lowest biosorption was 87.96% for reactive yellow.
Conclusion: The ADH17 is the most capable isolate and it is 100% similar to Sarocladium sp. This strain adsorbs a broad range of azo dyes, including mono-, di-, and tri- azo and acidic, basic, and reactive dyes as well. Sarocladium sp has a high ability to absorb various azo dyes.