APT (All-Purpose Tween) Agar is used for cultivating heterofermentative Lactobacilli from food products and other organisms requiring high thiamine content. Tryptone and Yeast Extract supply nitrogenous compounds, carbohydrates, and vitamins. Sodium Chloride maintains the osmotic balance. Potassium Phosphate serves as buffering agent. Sodium Carbonate is a neutralizing agent. Dextrose is the fermentable carbohydrate. Manganese Chloride, Magnesium Sulfate, and Ferrous Sulfate provide ions used in bacterial replication. Tween 80 is a surfactant for enhanced nutrient uptake and a source of fatty acids. Agar is the gelifying agent.