Exploitation of Laccase Producing Trametes versicolor (NBRC4937) for the Biodegradation of Triphenylmethanes (Crystal Violet) Dyes

Abstract

Crystal Violet (CV) dyes are extensively used in various industries but pose significant environmental concerns owing to their persistence and potential toxicity, this necessitate the needs to search for organism capable of degrading CV. Trametes versicolor was cultivated on potato dextrose yeast agar supplemented with guaiacol to assess its growth and laccase production. A mycelium disk was then inoculated into an experimental broth culture containing Crystal Violet dye as the carbon source and agitated on a shaker for 15 days at 150 rpm. Fourier-transform infrared spectroscopy (FTIR) and Gas chromatography–mass spectrometry (GC-MS) were used for the characterization of the crystal violet dyes and its degraded products, and this showed significant variations in peak presence and positions. These significant changes in the FTIR spectrum of the degraded dye metabolite provided confirmation of the biotransformation of the dye into other compounds, which was supported by the observation of distinct peaks at specific wave numbers. Specifically, peaks were observed at 110.75 cm-1, corresponding to the Alkyl-substituted ether and C-O stretch, at 458.23 cm-1 for the Tertiary alcohol and OH bond, at 1774.57 cm-1 for the Azo and N=N group, and at 1666.55 cm-1 for the Primary amine and NH stretch (C=C). GC spectral showed different peaks which represent some compounds formed during the biodegradation as interpreted by mass spectral data and fragmentation patterns from the NIST98 library. This demonstrated the capacity of T. versicolor to degrade CV dyes. The outcomes may lead to the development of efficient and environmentally friendly strategies for CV dye remediation, thus, reducing their environmental impact.