title: Presence of peptidase activities in different varieties of cheese.
abstract: Lactic acid bacteria (LAB) counts, PepX activity towards H-Phe-Pro-beta NA, and aminopeptidase activity towards H-Arg-beta NA. HCl, H-Lys-beta NA, H-Leu-beta NA, H-Pro-beta NA, H-Glu-beta NA derivatives have been evaluated in 32 commercial samples of cheese, one processed cheese, and one yoghurt. The presence of intracellular exo-peptidase activities in cheese extracts free from bacterial cells was detected, even after 1 year of ripening. An inverse ratio between the presence of viable lactic microflora and peptidase activity in the cheese extracts was observed. The importance of LAB starter exo-peptidases in the degradation of casein oligopeptides, and the key role of autolysis in the release of peptidases in the cheese, are discussed.
authors.affiliation: Istituto Sperimentale Lattiero Caseario, Lodi, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Gatti
authors.forename: M E
authors.initials: ME
authors.lastname: Fornasari
authors.forename: G
authors.initials: G
authors.lastname: Mucchetti
authors.forename: F
authors.initials: F
authors.lastname: Addeo
authors.forename: E
authors.initials: E
authors.lastname: Neviani
mesh_terms: D002611:Cheese / Q000382:microbiology*; D015169:Colony Count, Microbial; D020689:Exopeptidases; D006094:Gram-Positive Bacteria / Q000201:enzymology*; D010447:Peptide Hydrolases / Q000302:isolation & purification*
chemical_list: D020689:Exopeptidases; D010447:Peptide Hydrolases