Role of microorganisms in biodegradation of food additive Azo dyes: A review

Food additives Azo dyes are synthetic compounds added to foods to impart color and improve their properties. Some azo dyes have been banned as food additives due to toxic, mutagenic, and carcinogenic side eects. Long exposure to foods containing azo dye leads to chronic toxicity. Some microorganisms are capable to degrade these dyes and convert them to aromatic amines. In human body, microbiota can play a vital role in biodegradation of azo dyes by producing azo reductase. Aromatic amines are toxic, water-soluble and well absorbed via human intestine. In the current study, the role of microorganisms in biodegradation of six dyes related to azo group was discussed. These dyes are: Tartrazine E102, Sunset Yellow E110, Ponceau E124, Azorubine E122, Amaranth E123, and Allura Red E129 which are classified as the most harmful food additive dyes.   Key word: Food additive, azo dyes, microorganisms, azo reductase, aromatic amines.