Decolorization of synthetic dyes by Aspergillus sp

Aspergillus niger was isolated from the effluent of pulp and paper industry and screened for biodecolorization of six synthetic organic dyes. About 96% decolorization of 200 mg L⁻¹ of a mixture of Red 2 GC (nylon dye) and Congo red (cotton dye) occurred within 48 h in minimal medium containing 1% dextrose. Laccase production by the fungus was concomitant to the extent of dye decolorization. Almost 68% of 50 mg L⁻¹ of bromophenol blue was decolorized in the initial 1 h of contact by dead cells indicating that dye decolorization was mainly due to adsorption on fungal cell wall. In column studies, fungal biomass exhibited better efficiency in comparison to charcoal and flyash.