Casamino acid is the mixture of amino acids produced from acid hydrolysis of casein, a family of phosphoproteins found in mammalian milk. In comparison, tryptone describes casein that has undergone enzymatic degradation by the proteasetrypsin, leaving many smaller peptide chains alongside the free amino acids.[1]
Casamino acid is used as a component of microbiological growth medium to support protein synthesis. However, tryptophan, an essential amino acid, is lost while digesting the casein with strong acids.[2] Providing this abundant source of nitrogen can alter the phenotype of microorganisms, such as bacterial species recognizing nutrient-rich media and reducing their motility, as compared to their typical environmental behaviors.[3]
