Reduction of Sulphonated Water‐soluble Azo Dyes by Caecal Microorganisms from the Rat

Abstract

Abstract The degradation of Fast Red E, Amaranth, Ponceau 4R and Ponceau 6R in anaerobic incubates of rat caecal extract was studied by spectrophotometric scanning. The compounds underwent reduction of the azo linkage and thus loss of colour. The reaction rates seem to depend on the number rather than position of the sulphonate groups in the molecule.