Orange Serum Agar

 Principle

• Orange Serum Agar was originally developed by Murdock et al (1951) and Hays (1951) for examining citrus concentrates. Orange serum agar provides an acid environment and is also a source of carbon, and other essential nutrients. The media is composed of tryptone, yeast extract, dextrose, Dipotassium phosphate, orange serum, and agar.
• Tryptone and yeast extract provide nitrogenous, carbonaceous compounds, trace elements, and other essential growth nutrients including vitamins. Dextrose is a carbon and energy source. Phosphate buffers the medium.
• The low pH of the medium inhibits many commensal bacteria and encourages the growth of Lactobacilli and pathogenic fungi and yeast. Orange serum provides an optimal environment for the recovery of acid-tolerant microorganisms from citrus fruit products.

Use: Recommended for cultivation and enumeration of microorganisms associated with the spoilage of citrus products, cultivation of Lactobacilli, other aciduric organisms, and pathogenic fungi from food and clinical samples