SCHUBERT BROTH 500 grams/bottle

Schubert Broth is used to confirm the presence of coliforms and Escherichia coli. Biochemical tests are carried out in the same tube: fermentation of mannitol and indole production, which provides a saving of time, handling and space. The tubes with turbidity associated to the production of gas are considered positive. Indol production can be shown adding one or two drops of Kovacs reagent. Kovacs reagent detects the microorganism capable of cleaving the tryptophan. When these microorganisms are present in the medium they liberate indole that reacts with 4-dimethylaminobenzaldehyde to form a dark red dye. Peptone and tryptone provide nitrogen, vitamins, minerals and amino acids essential for growth. Mannitol is the fermentable carbohydrate providing carbon and energy. Sodium chloride supplies essential electrolytes for transport and osmotic balance. Magnesium sulfate and Ammonium sulfate are ions required in a big variation of enzymatic reactions, including DNA replication. Sodium citrate partially or completely inhibit Gram-positive organisms, coliforms and Proteus. The addition of tryptophan to the medium allows the performance of the Indole test for further E. coli confirmation.