Indole production from tryptophan test: principle, procedure and result

There are some enteric bacteria that produce indole during the hydrolysis of tryptophan. Not all bacteria hydrolyze tryptophan through the production of tryptophanase. However, there are few bacteria that do not produce indole. Indole production can be detected using Kuvac’s reagent that gives cherry-red a layer of reagent. 

So, indole production can be considered as characteristic property of…