Protease A activity and nitrogen fractions released during alcoholic fermentation and autolysis in enological conditions

• Published in: Journal of industrial microbiology & biotechnology Vol. 26; no. 4; pp. 235 - 240
• Main Authors: ALEXANDRE, H, HEINTZ, D, CHASSAGNE, D, GUILLOUX-BENATIER, M, CHARPENTIER, C, FEUILLAT, M
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer 01.04.2001; Springer Nature B.V
• Subjects: Aging; alcohols; Alcohols - metabolism; Amino acids; Amino Acids - metabolism; Apoptosis; Aspartic Acid Endopeptidases - metabolism; Autolysis; Biological and medical sciences; Biotechnology; Cell death; Chromatography; Chromatography, High Pressure Liquid; Enzymes; Fermentation; Fermented food industries; Food industries; Fundamental and applied biological sciences. Psychology; Hemoglobin; Hydrogen-Ion Concentration; Microbiology; Nitrogen; Nitrogen - metabolism; Organoleptic properties; Peptides; Proteases; proteinase A; Saccharomyces cerevisiae - cytology; Saccharomyces cerevisiae - enzymology; Saccharomyces cerevisiae - metabolism; Saccharomyces cerevisiae Proteins; Studies; Temperature; Time Factors; Wine - microbiology; Wines and vinegars; Yeast; Yeasts; Wine; Yeast; Serine endopeptidases; Omptin; Peptides; Enzyme; Ageing; Enology; Fungi; Autolysis; Peptidases; Enzymatic activity; Alcoholic fermentation; Aminoacid; Hydrolases; Ascomycetes; Saccharomyces cerevisiae; Thallophyta
• ISSN: 1367-5435; 1476-5535
• DOI: 10.1038/sj.jim.7000119

Determination of protease A activity during alcoholic fermentation of a synthetic must (pH 3.5 at 25 degrees C) and during autolysis showed that a sixfold induction of protease A activity occurred after sugar exhaustion, well before 100% cell death occurred. A decrease in protease A activity was observed when yeast cell autolysis started. Extracellular protease A activity was detected late in the autolysis process, which suggests that protease A is not easily released. Evolution of amino acids and peptides was determined during alcoholic fermentation and during autolysis. Amino acids were released in early stationary phase. These amino acids were subsequently assimilated during the fermentation. The same pattern was observed for peptides; this has never been reported previously. During autolysis, the concentration of amino acids and peptides increased to reach a maximum of 20 and 40 mg N l(-1), respectively. This study supports the idea that although protease A activity seemed to be responsible for peptides release, there is no clear correlation among protease A activity, cell death, and autolysis. The amino acid composition of the peptides showed some variations between peptides released during alcoholic fermentation and during autolysis. Depending on aging time on yeast lees, the nature of the peptides present in the medium changed, which could lead to different organoleptic properties.