Biodegradation and detoxification of Scarlet RR dye by a newly isolated filamentous fungus, Peyronellaea prosopidis

Efficient mitigation and management of environmental pollution caused by indiscriminate disposal of textile industry dyes and effluents deserves special attention. The aim of the present study was to evaluate the efficiency of Peyronellaea prosopidis for the decolorization, degradation and detoxification of Scarlet RR dye. Ultraviolet visible spectroscopy, Fourier Transform Infrared (FTIR) spectroscopy, High-Performance Liquid Chromatography and Gas Chromatography-Mass Spectrometry (GC-MS) were used in analyzing the degraded metabolites of the dye. P. prosopidis showed decolorization potency on Scarlet RR dye, dye mixture and textile industry dye effluent at a concentration of 10 mg L−1 and up to 90, 84 and 85% within 5 d. Maximum decolorization of Scarlet RR dye (10 mg L−1) by P. prosopidis was achieved at pH 6, temperature (35 °C) and biomass dose (1 g). Furthermore, 68, 88 and 91% reduction was recorded in the biological oxygen demand, chemical oxygen demand and color intensity of the textile industry effluent, respectively, after treatment with P. prosopidis. The degradation mechanism mediated by enzymes revealed significant inductions in lignin peroxidase (85%), laccase (58%), and manganese peroxidase (48%) after treatment of Scarlet RR dye with P. prosopidis. FTIR spectra of the metabolites showed significant disappearance and shifts in peaks in comparison with controls. Metabolites obtained from the GC-MS analysis were: N-(1l3-chlorinin-2-yl)-2-{methyl[(4-oxo-3,4-dihydroquinolin-2-yl)methyl]amino}acetamide; N-(1l3-chlorinin-2-yl)-2-{[(4-oxo-3,4-dihydronaphthalen-2-yl)methyl]amino}acetamide; 5-({[2-(1l3-chlorinin-2-ylamino) ethyl]amino}methyl)cyclohexa-2,4-dien-1-one and N-ethyl-1l3-chlorinin-2-amine after degradation of Scarlet RR dye. The detoxified status of the dye metabolites was confirmed with significant growth of plumule and radicle.