For selective isolation of yeasts and molds of significance in food spoilage
DRBC (Dichloran Rose Bengal Chloramphenicol) Agar (as per ISO) is a modification of original Rose Bengal Chloramphenicol agar by adding Dichloran. DRBC Agar is a selective medium that supports good growth of yeasts and molds. Peptic digest of animal tissue serves as a source of nitrogen, vitamins and minerals. Dextrose is a carbon and energy source. Magnesium sulfate provides divalent cations and sulfate. Monopotassium phosphate is a buffering agent. Dichloran is an antifungal agent used to reduce the colony diameter of spreading fungi. The presence of rose bengal in the medium suppresses the growth of bacteria and restricts the size and colonies of the more rapidly growing moulds. Chloramphenicol is included to inhibit the growth of bacteria present in environmental and food samples. Inhibition of growth of bacteria and restriction of spreading of more-rapidly growing moulds aids in the isolation of slow-growing fungi by preventing their overgrowth by more-rapidly growing species. Additionally Rose Bengal is taken by yeast and moulds colonies, which allows these colonies to be easily recognized and enumerated.