Peptone Water with Phenol Red is recommended for studying the ability of an organism to ferment a specific carbohydrate which aid in differentiation of genera and species. The formulation of Peptone Water makes it useful for cultivating non-fastidious organisms. This medium is recommended to study fermentation reactions of Yersinia enterocolitica. Peptone Water with pH adjusted to 8.4 is suitable for the cultivation and enrichment of Vibrio species.
Peptone Water is particularly suitable as a substrate in the study of indole production. Peptone used in Peptone Water is rich in tryptophan content. Peptone Water is also utilized as a base for carbohydrate fermentation studies with the addition of sugar and indicators such as bromocresol purple, phenol red or bromothymol blue.

for studying fermentation ability of Yersinia enterocolitica