Degradation of azo dye methyl red by Saccharomyces cerevisiae ATCC 9763

Abstract

Azo dyes are common dye groups widely used in different industries. Industrial effluents which contain these dyes pervade water resources and have various known and unknown physiological effects on living organisms. In this study, methyl red (MR) was proposed as a model azo dye to examine the capability of Saccharomyces cerevisiae ATCC 9763 for cleavage of the azo bond leading to decolourization. The spectrophotometry method showed that complete decolourization occurred statically during ≃12 h and this time reduced to several minutes less than 10 min where cell mass increased. Thin layer chromatography (TLC), mass spectroscopy and Fourier transform infrared (FTIR) confirmed degradation of methyl red to two constituents, N, N-dimethyl-p-phenylene diamine (DMPD) and 2-Aminobenzoic acid (2-ABA). In addition, a molecular mass of 122 observed in mass analysis results does not correspond with any compounds shown in the biodegradation pathway of methyl red developed by previous researchers; therefore, further study is needed to explain this variance.