Treasure from dross: Application of agroindustrial wastes-derived thermo-halotolerant laccases in the simultaneous bioscouring of denim fabric and decolorization of dye bath effluents

摘要

In this research paper, thermo-halotolerant laccases from microbial fermentation of agroindustrial residues by Achromobacter xylosoxidans HWN16 (Hb9c) and Citrobacter freundii LLJ16 (Ie1c) were evaluated for their ability to decolorize synthetic dyes and also wash indigo from denim fabric. Denim bioscouring and dye decolorization were monitored at different incubation times and uniquely high dye concentrations. The application of the free laccases in denim bleaching had no empirical effect, when applied unaided. However, their homogenization with an oxidized mediator (2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) yielded experiential effects after 6 h of incubation under orbital conditions, and improved discoloration of fabrics was observed with the aid of a dissection microscope. Furthermore, the dye baths were decolorized by the homogenates, after scouring of the fabrics, thereby producing colorless effluents. The results presented revealed the possibility of replacing conventional caustic and environmentally toxic approaches with cleaner sustainable methods for washing of denims, and dye decolorization.