title: Effect of protein hydrolysates on growth kinetics and aminopeptidase activities of Lactobacillus.
abstract: The goal of this study was to evaluate how two new hydrolysates from poultry by-products act on ten lactobacilli growth kinetics when supplemented to the growth medium. These effects were compared with ones induced by two most common commercial hydrolysates, i.e., tryptone and peptone. Growth medium, supplemented with one of new hydrolysates, 78T, as only nitrogen source, can sustain the maximum growth rate and the biomass yield in the same way of MRS, reach of different nitrogen sources. Moreover aminopeptidase activities (AA) of each strain were determined to investigate the effect of the growth condition on the modulation of aminopeptidase pattern. Five cell extracts of each ten strains, obtained from their cultivation in MRS and in the presence of the two common hydrolysates and the two new ones, were considered. AA was investigated against five different chromogenic substrates: β-naphthyl amide derivatives of L-anomers of leucine, lysine, proline, glycine-proline, and phenilalanine-proline. A great variability of AA was observed among the strains: also strains belonging to the same species showed peculiar AA profile.
authors.affiliation: Department of Food Science, University of Parma, Parco Area delle Scienze 48/A, 43124, Parma, Italy.
authors.forename: Federica
authors.initials: F
authors.lastname: Meli
authors.forename: Camilla
authors.initials: C
authors.lastname: Lazzi
authors.forename: Erasmo
authors.initials: E
authors.lastname: Neviani
authors.forename: Monica
authors.initials: M
authors.lastname: Gatti
mesh_terms: D000626:Aminopeptidases / Q000378:metabolism; D001426:Bacterial Proteins / Q000378:metabolism; D003470:Culture Media / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D007700:Kinetics; D007778:Lactobacillus / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism*; D011492:Protein Hydrolysates / Q000378:metabolism* / Q000494:pharmacology
chemical_list: D001426:Bacterial Proteins; D003470:Culture Media; D011492:Protein Hydrolysates; D000626:Aminopeptidases