Degradation and detoxification of synthetic dyes and textile industry effluents by newly isolated Leptosphaerulina sp. from Colombia

Background: Wastewaters from the textile industry are an environmental problem for the well-known Colombian textile industry. Ligninolytic fungi and their enzymes are an option for the treatment of these wastewaters; however, the Colombian biodiversity has not been deeply evaluated for fungal strains with ligninolytic activities. In this research, 92 Colombian fungal isolates were collected from four locations around the Aburrá valley, Antioquia, Colombia. Their decolorizing activities were evaluated using Novacron Red, Remazol Black and Turquoise Blue in solid and liquid media at different culture conditions. The best fungal isolate was evaluated in the bioremediation of two real effluents and its enzymatic extracts were used in the decolorization of the three dyes. Results: From 92 Colombian fungal isolates, Leptosphaerulina sp. exhibited the best decolorization percentage (>90 %) in solid and liquid cultures, and in agitated and un-agitated conditions. Leptosphaerulina sp. effectively decolorized the three dyes and two real effluents from textile industries. This decolorization was catalyzed by the production of significant quantities of laccase (650 U/L) and manganese peroxidase (100 U/L). Leptosphaerulina sp. enzymatic extracts exhibited decolorizing activity when ABTS as mediator was added. Leptosphaerulina sp. decolorized two real effluents from textile industries (>90 %) under conditions of low pH and glucose supplementation. Enzymatic degradation and decolorization products’ innocuity was demonstrated by cytotoxic and chromatographic analyses. Conclusion: Leptosphaerulina sp. was the best Colombian isolate. This fungal strain achieved a decolorization above 90 % for the three dyes and two real effluents from a textile industry. This decolorization was performed by producing significant amounts of laccase and manganese peroxidase. Leptosphaerulina sp. is an interesting prospect to treat waters polluted with dyes without the production of compounds dangerous for the environment. © 2016, Placido et al.