Glucose-phosphatic broth - a liquid nutrient medium with a strong buffer properties. The main use of environment - the cultivation of bacteria for the test of Fogasa-Proskauer. Bacterial growth is accompanied by a diffuse clouding of the medium, and the bacteria produce acetoin after the addition of reagent (α-naphthol, potassium hydroxide) stain culture liquid red. If it does not stir produces the characteristic "red ring" at the top of the tube.