Decolourisation and detoxification of CI Direct Blue 201 textile dye by two fungal strains of genus Aspergillus

Abstract

Two fungal strains capable of decolourisation of CI Direct Blue 201 textile dye were isolated from textile wastewater effluent sites in Sri Lanka and they were identified as Aspergillus aculeatus and Aspergillus nomius using 18s rRNA analysis. A. nomius and A. aculeatus showed 98 % decolourisation of CI Direct Blue 201 textile dye (50 mg/L) at 3rd day of incubation with the supplement of modified Kirk’s medium. Both fungal strains were found to be more effective for dye decolourisation at temperatures ranging from 24 ˚C to 36 ˚C. Further, it was found that the decolourisation potential increased at pH 5 and 10 under shaking condition (100 rpm) with the presence of glucose and nitrate as additional carbon and nitrogen sources. Seed germination assay showed less germination (22.2 ± 5.0 % and 10.0 ± 3.3 % for Oryza sativa and Vigna radiata, respectively) when seeds were exposed to the original dye in comparison to 100 % seed germination observed when exposed to fungal treated dye effluent, showing the detoxification of dye by the fungal isolates.