Evaluating the efficacy of wood decay fungi and synthetic fungal consortia for simultaneous decolorization of multiple textile dyes.

Wastewater from the textile industry dyeing process containing high loads of synthetic dyes leads to pollution of water with these toxic and genotoxic dyes. Much effort has been put towards developing biological systems to resolve this issue. Mycoremediation is a well-known approach using fungi to remove, degrade, or remediate pollutants and can be applied to decolorize textile dyes in industrial effluent. Fungal strains from four genera of Polyporales, namely Coriolopsis sp. TBRC 2756, Fomitopsis pinicola TBRC-BCC 30881, Rigidoporus vinctus TBRC 6770, and Trametes pocas TBRC-BCC 18705, were studied for decolorization efficiency, and R. vinctus was found to exhibit the greatest activity in removing all seven tested reactive dyes and one acid dye with a decolorization efficiency of 80% or more within 7 days under limited oxygen. This fungus simultaneously degraded multiple dyes in synthetic wastewater as well as industrial effluent from the dyeing process. To enhance the decolorization rate, various fungal consortia were formulated for testing. However, these consortia only trivially improved efficiency compared with using R. vinctus TBRC 6770 alone. Evaluation of R. vinctus TBRC 6770 decolorization ability was further performed in a 15-L bioreactor to test its ability to eliminate multiple dyes from industrial effluent. The fungus took 45 days to adapt to growth in the bioreactor and subsequently reduced dye concentration to less than 10% of the initial concentration. The following six cycles required only 4-7 days to reduce dye concentrations to less than 25%, demonstrating that the system can run efficiently for multiple cycles without the need for extra medium or other carbon sources.