Himedia Phenol Red Mannitol Broth

Phenol Red Mannitol Broth is recommended for mannitol fermentation studies of microorganisms.. Positive reaction is indicated by the change in colour of medium to yellow due to acid production as indicated by phenol red, a pH indicator in the medium. Gas production is indicated by the bubbles formation and entrapped in Durhams tube. Citrobacter freundii, Escherichia coli, Enterobacter aerogenes, Klebsiella pneumoniae and Salmonella Typhimurium are known mannitol fermentors and gives positive reaction. Salmonella Typhi, Shigella flexneri and Serratia marcescens ferments mannitol but do not produce gas. Proteus vulgaris does not ferment mannitol nor produce gas.