Fungal laccase
mediated Remazol Brilliant Blue R (RBBR) dye decolorization and degradation
Dhokane Juilee P., Patil Sunita H., Patil Sucheta N. and Patil Niranjan P.
Res. J. Biotech.; Vol. 20(1); 36-44;
doi: https://doi.org/10.25303/201rjbt036044; (2025)
Abstract
The use of dyes is inevitable in various industries, but sustainable decolorization
poses significant challenges that exhibit the need for microbial mediation. The
present study investigated the potential of C. unicolor laccase for degrading Remazol
Brilliant Blue R (RBBR) dye. The laccase treatment resulted in 91.8% decolorization
of 100 ppm and 34.8% decolorization of 600 ppm RBBR after 12 hours. Optimization
through one-variable-at-a-time (OVAT) analysis revealed optimal conditions: 20 U/ml
laccase concentration, pH 5 and a 10-hour treatment time. To examine the interactive
effects of temperature and dye concentration on degradation, response surface methodology
(RSM) with central composite design (CCD) was applied.
The predicted maximum decolorization of 80% at 275 ppm RBBR concentration and 40°C
closely aligned with the experimental result of 85%. UV-vis spectroscopy showed
a reduction in absorbance at 591 nm, while LC-MS identified degradation products
including hydroxyphenyl-containing compounds (m/z 216 and m/z 222) and sulfanilic
acid derivatives. The current study contributes to the advancement of efficient,
sustainable strategies for RBBR dye bioremediation that might address critical environmental
concerns related to dye pollution and will further enhance the development of bioremediation
technologies for industrial applications.
