Alkaline Peptone Water
Principles and uses
Alkaline Peptone Water is used for the enrichment of Vibrio cholera and Vibrio species from food, water, feces and clinical studies.
This medium has been recommended by various authors to increase the recovery of Vibrio species in fecal materials and other samples. Peptones provide nitrogen, vitamins, minerals and amino acids essential for growth. Sodium chloride supplies essential electrolytes for transport and osmotic balance and encourages the growth of Vibrio cholerae.
It is claimed that raising the medium’s pH leads the medium’s alkalinity to inhibit most of the unwanted flora background, leaving the viability of the Vibrio species intact.
Growth in tubes is indicated by turbidity compared to an uninoculated control. Additional steps are recommended, like plating onto a selective and non-selective media for isolation and morphology, and biochemical and serological studies for identification.