Bioaccumulation and biosorption of drimarene red dye by Aspergillus foetidus

An isolated fungus, Aspergillus foelidus, was found to uptake azo reactive dye(s) such as drimarene red under active growth and growth unsupportive conditions. Microscopy indicates preferential accumulation of drimarene red dye in the tips of fungal hyphae. The presence of 0.1% azide and phosphate in the fungal growth medium causes displacement of bound dye from the biomass. The key factors that influence the process of biosorption of dye in growth non-supportive medium are pH, temperature, and age and concentration of fungal biomass. Based on the Langmuir isotherm plots, the maximum fungal biosorption capacity (Q(o) value) was computed to be 344 mg g(-1) using the fungal spent medium at pH 2.5 and 60 degrees C. Sodium hydroxide is an effective agent for the leaching of dye from the loaded fungal biomass. The results suggest the possibility of applying the isolated fungus for decolourisation of textile mill wastewater.