Fungal consortium mediated efficient biodegradation of hazardous reactive dyes from textile effluent: An environmentally acceptable strategy

Abstract

The high concentration of reactive dyes in untreated textile effluent poses a significant challenge for efficient bioremediation. This study focuses on isolating and screening fungal strains from textile effluent collected from various locations to evaluate their decolorization potential against reactive dyes. Physicochemical parameters, including total dissolved solids (TDS), total suspended solids (TSS), electrical conductivity (EC), temperature, and pH, were analyzed following standard American Public Health Association (APHA) guidelines. Among the isolates, Aspergillus aculeatus (KCHW-1) and Cladosporium tenuissimum (MNDS-3) exhibited the highest decolorization efficiency and were utilized for consortium development. Effects of temperature, pH, agitation, carbon and nitrogen sources were also measured for optimization for decolorization potential of developed consortium. The fungal consortium, designated as KCMN-13, demonstrated remarkable decolorization efficiencies of 95.26, 97.51, and 98.23 % for Reactive Orange 16 (200 mg/L), Reactive Green 19 (200 mg/L), and Remazol Brilliant Blue R (200 mg/L), respectively. When applied to real textile effluent (20 L), the consortium achieved significant reductions in biological oxygen demand (BOD, 81.40 %), chemical oxygen demand (COD, 79.47 %), and TDS (76.71 %). Additionally, GC-MS analysis showed partially (three) to complete degradation (eight) of various compounds and also formation of new intermediates (ten) after treatment of developed fungal consortia revealed effectiveness of fungal consortia for efficient biodegradation of real textile effluent. Toxicity assessments based on seed germination and plant growth revealed that untreated textile effluent inhibited seed germination (77 %) and reduced root (12.36 ± 1.41 cm) and shoot lengths (9.43 ± 1.23 cm) compared to treated effluent and tap water (100 % germination). The treated effluent effectively mitigated toxicity, demonstrating the potential of the fungal consortium for sustainable bioremediation of textile effluent.