Fungi and their ability to decolourize azo and anthraquinonic dyes

One hundred and fifteen fungi from different physio-ecological groups were compared for their capacity to decolourize two structurally different dyes in agar plates. We found that the azo dye, Acid Red 183, was much more resistant to decolourization by the examined strains in both solid and liquid cultures. Among the tested fungi, 69 strains showed decolourization of the anthraquinonic dye, Basic Blue 22, within 5–14 days, and only 16 strains were able to decolourize the azo dye, Acid Red 183, within 21 days. Furthermore, the potential of selected strains for decolourization of dyes was examined with regard to their extracellular oxidative factors both enzymatic and non-enzymatic. In static aqueous culture, the three selected fungi (Bjerkandera fumosa, Kuehneromyces mutabilis, and Stropharia rugoso-annulata) formed fungal mats, which did not decolourize any dye beyond some mycelial sorption. In comparison to the static cultures, the agitated cultures (180 rpm) removed 75 to 100% of the colour of Basic Blue 22 and 20 to 100% of Acid Red 183 colour.