Decolorisation of Azo Dye Congo Red (CR) by Termitomyces sp. Biomass

Aims: A study was conducted to evaluate decoloration of azo dye, Congo Red (CR) using fungal hyphal mat of beneficial bacidiomycete Termitomyces sp. TMS7 (MW694830) as bio sorbent material.

Study design: Completely randomized block design (CRD).

Place and duration of study: Department of Agricultural Microbiology, Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu, India, between September 2019 and January 2020.

Methodology: Isolation of white rot fungus from basidiocarb was done and screened based on their ligninolytic enzyme activity and Isolate TMS 7 was selected as best isolate and identified through ITS 1 and ITS 4 primers. Efficiency of fungal biomass to decolorize Congo red was assessed and per cent decoloration and kinetics were calculated.

Results: Twelve fungal isolates were obtained and Isolate TMS 7 was selected as best isolate based on enzymatic activity. TMS 7 was identified as Termitomyces sp. using ITS 1 and ITS 4 primer. Ligninolytic enzymes i.e. cellulase (9.97 µ mol of glucose released/min/mg protein), and xylanase (9.55 µ mol of xylose released/min/mg protein) were quantified from the crude fungal extract of TMS 7, which was higher than standard (Termitomyces albuminosus -MTCC 1366). Decolorisation efficiency of termitomyces fungal biomass (1 g/100 ml) against different concentration of congo red dye (50-250 mg/L) was assessed. About 100 % (99.9) degradation was recorded in the minimum dye concentration of 50 mg/L within 3 days and 8 % decoloration was achieved at the highest dye concentration (250 mg/L) within 5 days.

Conclusion: Possible mechanism of degradation is the presence of lignolytic enzyme especially cellulase, xylanase in the culture filtrate and bio sorption of degraded product by the fungal cell wall components viz., chitin, glucan other complex polymers.