BIODEGRADATION OF MALACHITE GREEN AND RHODAMINE-B BY CECAL MICROFLORAOF RATS

Bio-degradation of two non-permitted dyes namely Malachite green and R hodamine B. commonly encountered in the food commodities, through rat caecal microflora was studied. Malachite green was biotransformed by c aecal microflora to one fluorescent metabolite with a Rf value of 0.09 . Incubation of Rhodamine B with caecal microflora resulted in two flu orescent metabolites with Rf values of 0.72 and 0.09. The D150 value o f Malachite green was quite low (10 min). while that of Rhodamine B co uld not be derived as the maximum degradation was only 32%. The result s suggest that Malachite green and Rhodamine B are biotransformed to d ifferent metabolites by rat caecal microflora which may help in deline ating the mechanism of carcinogenic potential of these two dyes. (C) 1 994 Academic Press, Inc.