LACTOSE BROTH (Eur. Pharma.) 500 grams/bottle

Lactose Broth is included in many Standard Methods for testing foods, dairy products and other materials for Enterobacteria and other Gram-negative microorganisms. It is also widely used for testing for coliforms in water and foods. It is used as preenrichment for testing foods and dairy products for Salmonella, where conservation processes may have injured or reduced their numbers. Preenrichment in a non-selective medium allows for repair of cell damage, diluting toxic or inhibitory substances, and provides a nutritional base for Salmonella. A preenrichment medium provides a higher ratio of Salmonella to non-Salmonella organisms after incubation. Most non-Salmonella bacteria ferment lactose whilst Salmonella does not. As lactose is metabolized, the pH decreases creating a bacteriostatic effect on competing organisms. Large water samples may require a double-strength of Lactose Broth to maintain correct concentration of the medium. Gelatin and Beef extract provide nitrogen, vitamins, minerals and amino acids essential for growth. Lactose is a complex carbohydrate energy source.