ANDRADE PEPTONE WATER (as per BIS)

Andrade Peptone Water is a basal medium used for testing carbohydrate fermentation by bacteria. Since bacteria vary in the ability to use certain sugars, the fermentation reactions are more important for differentiating and identifying bacterial species. The addition of individual carbohydrates to the medium allows microbiologists to show specific metabolic reactions that distinguish one organism from another.
Nutrients in the medium are derived from the peptic digestion of animal tissue, providing growth factors for microbes and enabling the determination of carbohydrate utilization to be evaluated independently. Andrade indicator is used as a visual indicator for fermentation activity. When an organism ferments the carbohydrate that has been added, acid is produced and the indicator changes color from straw yellow to pink or red. Organisms that cannot utilize the carbohydrate leave the medium unchanged. The medium is a staple in biochemical identification systems and is especially helpful in the differentiation of enteric and Vibrio species. Results obtained are often combined with additional biochemical tests for accurate organism identification.

A basal medium to study fermentation reactions by adding carbohydrates.