Supplementary file Evaluation of Congo red dye decolorization.docx

Decolorization and degradation of textile dye by endophytic fungi stand to be profitable and viable alternative over conventional methods in respect to eco-friendliness, cost-effectiveness and non-hazardous in nature. One of the active fungal endophytes <i>Colletotrichum gloeosporioides</i> isolated from plant <i>Thevetia peruviana </i>(Pers.) K. Schum.<i> </i>was screened for laccase production and Congo red dye decolorization. Various physicochemical parameters like dye concentration, carbon sources, nitrogen sources, temperature and pH were optimized and maximum decolorization rate was achieved at 100 mg/l of dye concentration (82%), glucose (79%), yeast extract (80%), 30°C (80%), and 7 pH (78%). SEM image and fungal biomass changes represent that fungus actively participated in the dye decolorization and had less/or no effect on biomass. An impressive regenerative ability of <i>C. gloeosporioides</i> after dye decolorization indicated the tolerance against dye which is found to be more advantageous over previous reports of dye decolorization by endophytic fungi. UV-Vis spectra, TLC, FTIR and HPLC results confirmed the decolorization and degradation process due to absorption and biodegradation. Phytotoxicity assay depicted that degraded products are less toxic to <i>Phaseolus mungo</i> compared to Congo red. Overall findings showed that <i>C. gloeosporioides </i>had a good decolorization ability against Congo red and had well the potential for application in dye wastewater treatment.