casein hydrolysate media casein hydrolysate media casein hydrolysate media is a general purpose culture medium used for cultivating various bacteria. it contains hydrolyzed casein as a source of amino acids, various minerals that are required for growth, and sodium or potassium phosphate as a buffering agent. casein hydrolyaste media is used for inducing staphylococcus aureus to produce enterotoxin, and is used to cultivate clostridium tetani.