Biodegradation of Congo Red by Manglicolous Filamentous Fungus Aspergillus flavus JKSC-7 Isolated from Indian Sundabaran Mangrove Ecosystem
Shreosi Chatterjee, S.K. Dey, M.V.R.K. Sarma, Punarbasu Chaudhuri, Surajit Das
Abstract
Abstract Textile industry is one of the major polluters of fresh water frequently contaminated with azo dye. Azo dyes are the largest class of synthetic organic dyes having one or more azo group (–N=N–) in their structure. Due to structural and molecular complexity, azo dyes are resistant to several physical and chemical treatments. However, the treatment of textile wastewater applying filamentous fungi offers several advantages over conventional cleanup techniques in terms of cost-effectiveness and environmental friendliness. The present study was focused on the degradation of Congo Red using manglicolous fungus Aspergillus flavus JKSC-7 via both biosorption and enzymatic degradation. Decolorization experiment showed that the fungal strain was able to decolorize 96.92% of Congo Red even under metal stress conditions. Light microscopy and X-ray diffraction analysis suggested that initially the dye was decolorized through biosorption to the fungal cell wall. ATR-FTIR spectroscopy and SDS-PAGE study demonstrated synthesis of fungal laccase and manganese(II) peroxidase to aid Congo Red degradation. Further, activities of laccase and manganese(II) peroxidase were found to be maximal at pH 5.0 and temperature 30 and 40°C, respectively.