Enzymatic Decolorization of Remazol Brilliant Blue Royal (RB 19) textile dye by White Rot Fungi

Abstract

Synthetic dyes are widely used by different industries with over 7 ×105 metric tons produce globally each year. Dyes pose adverse effects including chemical oxygen demand, visual pollution, cytotoxicity, genotoxicity, mutagenicity and carcinogenicity on various types of living organisms. The versatile white rot fungi (basidiomycetes fungi) have developed specialized ligninolytic enzymes for reductive cleavage of dyes and xenobiotics. The present study optimized the decolorization of Remazol brilliant blue royal (RBBR) dye by enzymatic extracts of Coriolus versicolor and Pleurotusostreatus. Experiments were carried out by varying one parameter i.e. pH (2.5-6.5), temperature (30oC-60oC), enzyme activity (3.3U-20U), dye concentration (10mg/L-125mg/L) and time (0-480mins), while others constant to study its effects on decolorization of RBBR. From the results obtained, the optimum conditions for decolorization of RBBR by extracts of C. versicolor and P. ostreatus were pH 4.0, temperature of 300C, enzyme activity 20U, dye concentrations of 100mg/L and 50mg/L for C. versicolor and P. ostreatus respectively at the end of 480 minutes. At the optimized conditions, decolorizations for C. versicolor and P. ostreatus were 80.42% and 70.42% respectively. Highest laccase activity (19.50U) was recorded in C. versicolor compare to P. ostreatus (1.41U).