Investigation of the potential of microbial stripping of dyed cotton fabric using white rot fungi

Abstract

This paper reports the results of a novel approach of investigating the potential of biochemical stripping of cotton fabric dyed with reactive black B dye using five indigenous strains of white rot fungi (WRF) in Kirk’s basal salts medium. The color stripping was measured in terms of color strength (K/S value) before and after treatment. Among the five strains of WRF, Ganoderma lucidum IBL-05 showed the best stripping (20.11%) in 15 days of incubation under continuous shaking conditions (120 rpm) at pH 4.5 and 35 °C. The biochemical stripping process using G. lucidum IBL-05 was developed by optimizing various parameters like temperature, pH, additional carbon and nitrogen sources, low molecular weight mediators and metal ions. Supplementation with additional carbon and nitrogen sources enhanced the stripping to 67.73% under optimum conditions of pH 4 and temperature 35 °C. Wheat bran (1 g/100 mL) and peptone (0.2 g/ 100 mL) were found to be the best carbon and nitrogen sources, respectively. The addition of MnSO4 (1 mM) as a mediator of ligninolytic enzymes and ZnSO4 (1 mM) as a metal ion activator, further enhanced the stripping to 90.59% under optimum conditions generating a transparent effluent at the end of 15 days.