Discolorization of Cochineal Textile Effluent by Ligninolytic Fungus Under Solid and Liquid Conditions.

Process of cotton dyeing with cochineal extract generates effluent coloured, where the principal pollutant present is the carminic acid. This acid is a natural antraquinone with a radical glycoside. However, its effects on the environment are unknown. Therefore there were performed preliminary tests of decolourization effluent from the cotton dyeing with the cochineal extract by ligninolytic fungus Trametes versicolor. To develop the research, two different media were used: solid agar-agar’s medium and liquid Kirk‘s medium. Solid medium was prepared with different concentrations of the effluent (5-65%) by triplicate; fungus was inoculated and incubated during 8 days at 28 ±1 ^oC. It was observed an inverse correlation between radial fungus growth rate and effluent concentration as expected. As fungus was growing, transparent areas on the solid medium were observed. Fungus was exposed to an effluent concentration (50%) in a liquid system considering an experimental design by triplicate. Flasks were incubated during 7 days at 28 ±1 ^oC; at 125 rpm Three variables and two levels were considered: with and without Kirk’s medium, absent and presence of glucose and fungi. Variables studied were pH, dry weight and absorbance. T. versicolor was able to reduce color in the system compare with the control without fungus. No significant discolorization of effluent was found in control treatments. Also, fungal growth was affected by effluent concentration in the medium. However, discolorization was found in all treatments with fungus. Results showed that T. versicolor has potential to be applied for degradation of this type of effluents.