Studies on the Biodegradation of Azo Dyes by White rot Fungi Daedalea Flavida in the Absence of External Carbon Source

Dye degradations by white rot fungi have been studied in the presence of an easily metabolizable external carbon source that is unlikely to be present in waste water. For wastewater treatment, it is important to study the potential of white rot fungi to decolorize the azo dyes in the absence of external carbon source. The potential of D. flavida to decolorize the azo dyes in the absence of external carbon source has been studied. Decolorization of Amaranth, Metanil yellow, Trypan blue and Chlorazole black was studied with D. flavida. Decolorization was studied in 250 ml Erlenmeyer flasks at 36 degrees C, stationary, 50 ml N-limited medium with dye 50 mg/l in the absence and presence of glucose. Decolorization and enzyme activity were measured. It was observed that decolorization for Amaranth was 99% after five days, Metanil yellow 82.5% after 10 days, Trypan blue 99% and Chlorazole black E 72% after 10 days of treatment both in the absence and presence of glutose. UV - VIS spectra of dyes before and after the treatment of dyes with D. flavida showed a decrease in the absorbance at their maximum absorption wavelength in visible region and a shift towards shorter wavelength indicating the degradation of dyes. It showed that D. flavida could be used for the treatment of azo dyes in waste water without an external carbon source for reduction of cost.