Efecte de lachancea thermotolerans i l'àcid l-làctic sobre oenococcus oeni i la fermentació malolàctica

Entity: Universitat Rovira i Virgili (URV)

Confidenciality: No

Education area(s): Begudes Fermentades

Title in different languages: Efect of lachancea thermotolerans and l-lactic acid on oenococcus oeni and malolactic fermentation

Abstract: In the last years, the study and use of non-Saccharomyces yeasts has increased, but the effects on lactic acid bacteria (LAB) and malolactic fermentation (MLF), in part, remain unknown. Lachancea thermotolerans is a yeast characterized by the production of Llactic acid. The aim of this study is to address the effects of this compound on MLF. Six strains of L. thermotolerans were studied, including a commercial strain. To determine the production capacity of L-lactic acid, the strains were tested in individual alcoholic fermentation (AF) in synthetic must. Some of these strains were selected to perform AF in synthetic must, with sequential inoculation of Saccharomyces cerevisiae at 48 hours. The resulting wines were used to perform MLF, using two strains of Oenococcus oeni. On the other hand, MLFs in synthetic wine were performed, studying 3 conditions of Llactic acid: 0 g/L, 2.5 g/L and 5 g/L. Two strains of O. oeni were also studied in these trials. In both individual and sequential AF, strains of L. thermotolerans produced very low levels of L-lactic acid, probably due to the composition of the must. Therefore, the effect of L-lactic acid in subsequent MLFs could not be determined. Nevertheless, the best fermentative kinetics in MLF were observed in wines produced with L. thermotolerans and S. cerevisiae, but not S. cerevisiae alone. In the trials with synthetic wine, the best condition of L-lactic acid was 0 g/L, and the higher the concentration, the more difficult the MLF development, although the tolerance to L-lactic acid was strain dependent. At 5 g/L of L-lactic acid none of the strains could perform MLF. Thus, L-lactic acid exhibited a potential inhibitory effect on BAL and MLF, depending on the concentration, but more studies and conditions are required to confirm these results.

Subject: Enologia

Academic year: 2019-2020

Language: Català

Work's public defense date: 2020-09-10

Subject areas: Enology

Student: Figuerola Gatell, Pol

Work's codirector: Reguant Miranda, Cristina

Department: Bioquímica i Biotecnologia

Creation date in repository: 2021-03-25

TFM credits: 15

Keywords: Lachancea thermotolerans, Oenococcus oeni, wine, L-lactic acid, malolactic fermentation, sequential inoculation

Title in original language: Efecte de lachancea thermotolerans i l'àcid l-làctic sobre oenococcus oeni i la fermentació malolàctica

Access Rights: info:eu-repo/semantics/openAccess

Project director: Beltran Casellas, Gemma