K.A.A. PRESUMPTIVE BROTH 500 grams/bottle

KAA Presumptive Broth (Kanamycin, Aesculin, Azide) is a selective medium for the isolation of intestinal enteroccoci in foods. KAA Presumptive Broth is used in conjunction with KAA Confirmatory Agar (Cat. 1027). Kanamycin, sodium azide and sodium citrate have a great inhibitory effect on the accompanying bacterial flora, they inhibit the growth of Gram-positive and Gram-negative bacteria, and the medium is highly selective for esculin-hydrolyzing enterococci. Ferric ammonium citrate is an indicator which detect the esculin-hydrolysing bacteria. They hydrolyze the glucoside esculin to give glucose and esculetin. Tubes have a black color due to the reaction of the resulting esculetin with the iron ions. Tryptone provides nitrogen, vitamins, minerals and amino acids essential for growth. Yeast extract is a source of vitamins, particularly of the B-group essential for bacterial growth. Sodium chloride supplies essential electrolytes for transport and osmotic balance. The presence of intestinal enterococci is an indicator for faecal en contamination, especially when the contamination occurred long ago and the less resistant coliform bacteria, including Escherichia coli, are already dead when the analysis is carried out.