Orange Serum Broth 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 Mixture provides the adequate acid environment for recovering acid-tolerant microorganisms. Dipotassium Phosphate serves as pH buffer.