Himedia Phenol Red Sucrose Agar

Phenol Red Sucrose Agar is used for studying sucrose fermentation by the pure cultures of microorganisms. Positive reaction is indicated by the production of a yellow colour in agar due to acid production. Gas production is indicated by the splitting of agar or by the bubbles formation. Klebsiella pneumoniae and Proteus vulgaris are known sucrose fermentors and gives positive reaction. Salmonella Typhimurium, Escherichia coli, Alcaligenes faecalis and Shigella flexneri do not ferment sucrose, hence there is no colour change of the medium.