title: Effects of yeast proteolytic activity on Oenococcus oeni and malolactic fermentation.
abstract: Alcoholic fermentation of synthetic must was performed using either Saccharomyces cerevisiae or a mutant Deltapep4, which is deleted for the proteinase A gene. Fermentation with the mutant Deltapep4 resulted in 61% lower levels of free amino acids, and in 62% lower peptide concentrations at the end of alcoholic fermentation than in the control. Qualitative differences in amino acid composition were observed. Changes observed in amino acids in peptides were mainly quantitative. After alcoholic fermentation, each medium was inoculated with Oenococcus oeni. Malolactic fermentation in the medium with the Deltapep4 strain took 10 days longer than the control. This difference may have been due to a difference in the nitrogen composition of the two media. Free amino acids and amino acids in peptides were poorly consumed by O. oeni. Thus, the qualitative aspects of nitrogen composition, which depend in part on yeast metabolism, may be a determinant for the optimal growth of O. oeni in wine.
authors.affiliation: Laboratoire de Microbiologie, Institut Universitaire de la Vigne et du Vin Jules Guyot, Université de Bourgogne, Dijon Cedex, France.
authors.forename: Michèle
authors.initials: M
authors.lastname: Guilloux-Benatier
authors.forename: Fabienne
authors.initials: F
authors.lastname: Remize
authors.forename: Laurent
authors.initials: L
authors.lastname: Gal
authors.forename: Jean
authors.initials: J
authors.lastname: Guzzo
authors.forename: Hervé
authors.initials: H
authors.lastname: Alexandre
mesh_terms: D000596:Amino Acids / Q000032:analysis; D010450:Endopeptidases / Q000494:pharmacology*; D005285:Fermentation; D006095:Gram-Positive Cocci / Q000187:drug effects* / Q000378:metabolism; D008291:Malate Dehydrogenase / Q000378:metabolism*; D008293:Malates / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D014920:Wine / Q000382:microbiology
chemical_list: D000596:Amino Acids; D008293:Malates; D029701:Saccharomyces cerevisiae Proteins; C037731:malolactic enzyme; D008291:Malate Dehydrogenase; D010450:Endopeptidases; D009584:Nitrogen