Decolorization of a variety of dyes by Aspergillus flavus A5p1.

Aspergillus flavus: fungal strain A5p1 is reported here to decolorize a variety of dyes under broad environmental conditions. For the 15 dyes tested, the decolorization efficiencies ranged from 61.7 to 100.0% at an initial concentration of 100 mg/L. Direct Blue 71 (DB71), Direct Blue 86 (DB86), and Reactive Blue 19 (RB19) were selected as models for comparing decolorization performance. The results show that biosorption and biodegradation work together in the strain to remove the pigments; the effect of biosorption was stronger for DB71 and DB86, whereas the effect of biodegradation was stronger for RB19. For DB71 and DB86, the decolorization rate surpassed 90% with inactivated biomass under acidic conditions and with living biomass under alkaline conditions. DB19 achieved the highest removal rate of 90% under neutral conditions. The strain could effectively decolorize high concentrations of dyes up to 1000 mg/L, which was achieved mainly via biosorption at concentrations below 500 mg/L and via biodegradation at concentrations above 500 mg/L. The findings suggest that A5p1 has a strong adaptability to different dye types and environmental conditions and can, therefore, be potentially used in biological processes for the treatment of dye-containing wastewater.