Citrate Azide Agaris recommended for selective cultivation of Enterococci in dairy products.Tryptone and yeast extract in the medium provide nitrogen, carbon, long chain amino acids, vitamins and other essential growth nutrients. The high concentrations of sodium citrate inhibit the growth of the accompanying microbial flora. Tetrazolium blue is reduced by Enterococci to form blue coloured colonies. Sodium azide helps in the selective isolation of Enterococci.
1.Vanderzant C. and Splittstoesser D. F., (Eds.), 1992, Compendium of Methods for the Microbiological Examination of Foods,3rd Ed., APHA, Washington, D.C.2.Frank & Yousef,2004, Standard Methods for the Examination of Dairy Products,17th Ed.