Bioremediation of textile industrial effluents by Fomitopsis pinicola IEBL-4 for environmental sustainability

Industrialization not only revolutionized the life in the past few decades but also leads to environmental pollution by the continuous addition of effluents. There is need to develop techniques for the economic bioremediation of toxic effluents to maintain sustainable environment. In current study, the textile industrial effluent’s biodegradation potential of a locally isolated brown rot fungi, Fomitopsis pinicola IEBL-4, was analyzed and optimized. Response surface methodology under Box–Behnken design was employed for the biodegradation of three industrial effluents. The analysis of biodegradation is followed by the study of the ligninolytic enzymes, i.e., manganese peroxidase, lignin peroxidase, and laccase during the process. Biological oxygen demand (BOD) and chemical oxygen demand (COD) of effluents after treatment were determined to check the quality of the biodegradation process. The results showed that there was 72.06±1.76%, 75.15 ± 1.72%, and 79.02 ± 1.62% biodegradation of MT, FST, and ST effluents, respectively after optimization of fungal growth conditions. Addition of various carbon and nitrogen sources further increase biodegradation 15%, 5%, and 9% for MT, FST, and ST effluents, respectively. There was continuous decrease in the values of BOD and COD after each optimization step and values were well below the WHO recommended after final biodegradation. The BOD of MT effluent reduces from 358.30 mg/L to 49.31 ± 0.87 mg/L, 347.2 mg/L to 51.12 ± 0.76 mg/L for FST effluent, and 412.2 mg/L to 45.34 ± 0.9 mg/L for ST effluent after optimization of biodegradation at two stages. The study of ligninolytic enzymes showed that these are involved in the biodegradation process and lignin peroxidase is the most active among all three. The maximum activities calculated were 942.60 ± 5.70 U mL⁻¹ min⁻¹ for LiP, 694.20 ± 4.10 U mL⁻¹ min⁻¹ for MnP, and 435.60 ± 3.30 U mL⁻¹ min⁻¹ for laccase. The enzymatic activities vary with the biodegradation of the effluent suggested dyes dependent secretion of the enzymes. This study could be concluded that F. pinicola IEBL-4 is suitable fungus for the bioremediation of textile industrial effluents.