Orange Serum Agar is used for the cultivation of aciduric microorganisms, particularly those associated with the spoilage of citrus products. The low pH of fruit juices makes citrus fruit products susceptible to spoilage by yeasts, molds, Lactobacillus and Leuconostoc. Tryptone and Yeast Extract supply nitrogenous sources, carbohydrates, B-complex vitamins, and minerals for general growth requirements. Dextrose is the fermentable carbohydrate. Orange Serum provides the adequate acid environment for recovering acid-tolerant microorganisms. Potassium Phosphate serves as pH buffer and Agar is the gelifying agent.