Influence of non-sacharomyces yeast growth on the metabolism of nitrogenous compounds in lactic acid bacteria from wine

摘要

A comparative study of the influence of Hanseniaspora uvarum metabolism on the growth and physiology of two lactic acid bacteria involved in vinification: Lactobacillus hilgardii 5w and Oenococcus oeni X2L was carried out. At different yeast growth times in grape juice medium, fermented broth was inoculated with L. hilgardii or O. oeni and incubated for 48 h at 30oC. When O. oeni grown in the culture supernatant after 0, 3 and 8 hours of yeast growth (M1, M2 and M3 respectively), the growth rate and final biomass were not modified. With L. hilgardii a decrease of both parameters was observed. After 12, 24 and 34 h of yeast growth (M4, M5 and M6 respectively), the results for both microorganisms were similar: the growth rate increased and the final cellular mass decreased. When O. oeni was inoculated in M1, M2 and M3 media, an initial decrease of proteins directly related to amino acids production was observed. With L. hilgardii the amino acid and proteins concentrations diminished. In M4, M5 and M6 media O. oeni showed that the protein concentrations remained constant and the amino acid concentrations diminished. The results obtained with L. hilgardii were different with a higher protein consumption rate without significative amino acids modification. The amino acids increment in the first hours of O. oeni growth could regulate the protease production achieving the equilibrium between amino acids production and utilization. The high proteolytic activity in L. hilgardii could be responsible of the amino acids increase despite its consumption.