BRYANT AND BURKEY MEDIUM

Description

Bryant and Burkey Medium is used to enumerate the spores of gasogenic clostridia that are responsible for swelling of cheese in dairy industry. In normal conditions of use, the medium allows the growth of other microorganisms also which are not directly related to cheese alteration, e.g. Clostridium sporogenes or Clostridium butyricum. Germination and growth of butyric acid bacteria (BAB) causes severe defects in cheese with silage being the main source of BAB spores in cheese milk. Clostridia spores are heat resistant and therefore can contaminate cheese brines. The gas produced by the growth of clostridia swells the cheese and is responsible for defect known as butyric swelling, resulting in bad taste. The main species causing this butyric swelling defect is Clostridium tyrobutyrium. Recommended technique for estimation of Clostridium is to enumerate the spores by the MPN method.