413. The growth requirements of lactobacilli in relation to cheese flavour development

Abstract

An attempt was made to devise a medium for the growth of lactobacilli which would simulate the nutritive conditions existing in ripening cheddar cheese. The basal medium finally used contained soluble digestion products of casein (formed by the action of rennet), lactose, lactate and phosphate. This medium gave a fair, but not a very heavy growth of flavour-producing lactobacilli isolated from cheddar cheese, and it was evidently deficient in growth-promoting power as compared with some media used in the laboratory. Additions of potassium and manganese salts to the casein digest medium gave a significant increase in growth. Potassium had the effect of off-setting the inhibition caused by the presence of an excess of sodium salts such as are normally present in cheese. The implications of the results in cheese ripening and their possible application in cheese manufacture are discussed.