Growth Response of Lactobacillus casei variety casei to Proteolysis Products in Cheese during Ripening

Abstract

Water extracts of Cheddar cheese at different ages up to 180 days were frac- tionated on Sephadex G-50 with pyridine- acetic acid buffer pH 5.1. Six and nine fractions were obtained from fresh and ripened cheese, respectively, some of which stimulated growth. A fraction con- taining riboflavin was stimulatory to Lactobacillus casei variety casei. The stimulatory fractions contained N-acetyl- hexosamine and 23 to 27.8% glutamic acid of the constituent amino acids. Most of the alphas-casein disappeared from the cheese at 35 days while beta-casein re- mained. Para-kappa-casein was not pro- teolyzed at 170 days of cheese ripening. The significance of alpha-casein proteoly- sis in Cheddar cheese is discussed.