Biosorptive and Biodegradative Mechanistic Approach for the Decolorization of Congo Red Dye by Aspergillus Species

In this work, Aspergillus terreus GS28 and Aspergillus flavus CR500 isolated from industrial waste sludge examined for the decolorization of Congo red (CR) dye. The rate of CR decolorization raised due to optimum pH, temperature, carbon, nitrogen, and heavy metals. In the comparative study, A. terreus has the maximum ability (95%) to decolorize CR (≈ 100 mg L−1) as compared with A. flavus (92.96%) under optimized condition after 120 h. GC–MS and FTIR analysis of the fungal-metabolite and fungal-biomass shows bio-degradation and biosorption processes respectively. The degraded products were benzenepropanic (Rt-26.147), 3, 4-diaminonapthelene-1-sulfonic acid, and benzenedicarboxylic acid (Rt-26.660) by A. terreus, and benzenedicarboxylic acid (Rt-41.467) by A. flavus. The phytotoxicity assay revealed that a decrease in toxicity of the degraded product towards the growth and germination rate of two plant seeds compared to CR. Thus, the finding suggests that both the fungi act promising CR remediation candidates, induces restoration of CR polluted wastewater and save soil-land.