Orange Serum Agar is used for the cultivation of aciduric microorganisms, particularly those associated with the spoilage of citrus products.

Principles: 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.