Biodiscoloration, Detoxification and Biosorption of Reactive Blue 268 by Trametes sp. M3: a Strategy for the Treatment of Textile Effluents

Abstract

The concern with the environment and the depletion of natural resources has aroused the interest for the rational use and recycling of water. Therefore, this study evaluated the capacity of the Trametes sp. M3 isolate in the bioremediation of Reactive Blue (RB) 268 dye and its potential for use as an adsorbent in the treatment of textile effluents. In a solid medium containing RB 268, the discoloration rate was 1.00 and the growth rate was 1.4 cm/day. When evaluated in the in vivo biodiscoloration process, 100% of the dye lost its color after 120 h. The oxidative enzyme laccase was found in cultures containing the dye with high activity, indicating that it underwent induction. The chromatogram after cultivation of the fungus showed that there was a change in the structure of RB 268. The mycelium of the culture with the dye was analyzed by FTIR, pointing to an adsorption of RB 268 or its metabolites despite the absence of the color. In the biosorption, the best results were obtained when the mycelium was treated with HCl. The toxicity of the medium decreased after the cultivation of the fungus allowing the survival of the microcrustaceans in the acute toxicity bioassay.