PALCAM Medium（Granular）

Testing principle:Casein Pancreatic Digest， Heart Pancreatic Digest， and Meat Peptic Digest provide the essential carbon and nitrogen sources required for growth；Yeast Extract and Starch provide carbon and nitrogen sources， vitamins， and growth factors；Sodium Chloride maintains balanced osmotic pressure; Glucose provides the carbon source; Mannitol serves as a fermentable sugar; Phenol Red serves as a pH indicator；Lithium Chloride and other antibiotics inhibit the growth of Gram-negative bacteria and most Gram-positive bacteria; Agar serves as the solidifying agent of the medium; Phenol Red serves as a pH indicator. Some Listeria species can ferment mannitol to produce acid， turning the Phenol Red indicator yellow. However， non-Listeria organisms such as Staphylococcus and Enterococcus may occasionally grow on this medium， fermenting mannitol to produce acid and turning the colonies and the surrounding medium yellow. When Listeria grows on this medium， it hydrolyzes aesculin to produce 6，7-dihydroxycoumarin， which reacts with the ferric ions in Ferric Ammonium Citrate to form a black compound， thereby turning the medium black; Lithium Chloride and other antibiotics inhibit the growth of Gram-negative bacteria and most Gram-positive bacteria; Agar serves as the solidifying agent of the medium.