This is a selective medium for the isolation and enumeration of yeasts and moulds in dairy products. It is in according to a typical formulation of The International Organisation for Standardisation (ISO).
Yeast extract acts as a source of nitrogen, carbon and vitamins in this medium. Glucose is a fermentable carbohydrate. Although the medium has a low pH it is made more selective by the inclusion of chloramphenicol, an antibiotic selective agent.