Recommended by BIS for detection of Indole production by Escherichia coli . A slightly different formulation of Peptone water/ Peptone water with phenol red is recommended for studying the ability of organisms to ferment a specific carbohydrate which aids in differentiation of genera and species. Peptone water with phenol red is recently recommended by ISO committee 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.