Biodecolorization and biodegradation of reactive Levafix Blue E-RA granulate dye by the white rot fungus Irpex lacteus

The treatment of effluents from textile industry with microorganisms, especially bacteria and fungi, has recently gained attention. The present study was conducted using white rot fungi Irpex lacteus, Trametes hirsuta, Trametes sp., and Lentinula edodes for the decolorization of reactive textile Levafix Blue E-RA granulate dye. I. lacteus resulted in the best decolorization and degradation of the dye within four days. Therefore, more detailed studies were carried out using I. lacteus. The decolorization was evaluated at various concentration, pH values, and temperatures. The activities of laccase, manganese peroxidase, and lignin peroxidase enzymes were estimated to reveal the roles of enzymes in decolorization. The colorless nature of the fungal cells revealed that decolorization occurred through degradation, and confirmed by analysis of the metabolites by UV–visible spectroscopy and High Performance Liquid Chromatography after decolorization. The metabolites were identified by Gas Chromatography–Mass Spectrometry, and functional group analysis was performed by Fourier Transform Infrared Spectroscopy. The degraded dye metabolites were assessed for phytotoxicity using Vigna radiata and Brassica juncea, which demonstrated nontoxic nature of the metabolites formed after degradation of dye.

► White rot fungi “Irpex lacteus” was utilized for the biodegradation of Textile dye “Levafix Blue E-RA”.
► The degradation of the dye was rapid and complete degradation of the dye was observed.
► The liberated products after biodegradation were nontoxic.
► The added advantage of biodegradation using fungi is degradation of dye at higher concentrations.