AbstractThe textile industry generates enormous starch effluent from the desizing process that can be utilized as a nutrient source for fungal growth and simultaneous dye decolorization. In the present study, Trichoderma reesei was used as a potential fungal isolate for the decolorization of reactive dyes using a minimal salt media for growth. The dye removal of Reactive blue 13, Reactive red 198, Reactive yellow 176, and Reactive black 5 were 95.35, 88.17, 86.01, and 94.84 mg L−1, respectively, by fungal biomass at 100 mg L−1 of initial dye concentration in 48 h was achieved. T. reesei showed decolorization of dyes at initial concentrations upto 500 mg L−1 with high dye uptake capacity. The glucose (5 g L−1) and yeast extracts (2.5 g L−1) were optimal for maximum dye decolorization. The utilization of starch effluent as an alternative nutrient source supplemented with 3.5 g L−1 glucose as growth media by T. reesei showed >85% of decolorization of Reactive blue 13 (100–200 mg L−1). Thus, starch effluent could be partially supplemented with glucose to support fungal growth and dye decolorization, eliminating the requirement of minimal salts for dye decolorization that follows a sustainable approach.