for detection of indole producing microorganisms.
TRYPTONE BROTH (TRYPTONE WATER) (VEG.) is used for detection of indole producing microorganisms. Tryptone water may also be used for differentiation of other bacteria based on indole production. It consists of Veg. CEH enzymatic hydrolysate which is a good substrate that has high levels of the amino acid like tryptophan; it also contains some other amino acids. To utilize tryptophan, a bacterium must produce tryptophanase. Tryptophanase catalyzes the hydrolysis of tryptophan to ammonia, pyruvate and indole. As indole is produced as an end product that is unique to bacteria that produce tryptophanase, one can determine if a given bacteria has tryptophanase activity by testing for the presence of indole. Addition of Kovac’s reagent, which contains chemicals that react with indole to produce a red-ring at the top of the broth. Indole combines with the aldehyde present in the above reagent to give red colour in the alcoholic layer. For complete identification of the organisms, further biochemical confirmation is necessary. Sodium chloride helps maintaining the osmotic balance.