terclim by ICS banner
IVES 9 IVES Conference Series 9 INVESTIGATION OF MALIC ACID METABOLIC PATHWAYS DURING ALCOHOLIC FERMENTATION USING GC-MS, LC-MS, AND NMR DERIVED 13C-LABELED DATA

INVESTIGATION OF MALIC ACID METABOLIC PATHWAYS DURING ALCOHOLIC FERMENTATION USING GC-MS, LC-MS, AND NMR DERIVED 13C-LABELED DATA

Abstract

Malic acid has a strong impact on wine pH and the contribution of fermenting yeasts to modulate its concentration has been intensively investigated in the past. Recent advances in yeast genetics have shed light on the unexpected property of some strains to produce large amounts of malic acid (“acidic strains”) while most of the wine starters consume it during the alcoholic fermentation. Being a key metabolite of the central carbohydrate metabolism, malic acid participates to TCA and glyoxylate cycles as well as neoglucogenesis. Although present at important concentrations in grape juice, the metabolic fate of malic acid has been poorly investigated. In this work, we used 13C-labeled malic acid to understand the main routes of its consumption and its de novo production. Two strains selected for their opposed malic acid metabolism were compared by combining several analytical chemistry techniques. The isotopic enrichment of intracellular amino acids was measured by GC-MS, the relative quantification of intra- cellular and extracellular labeled compounds was achieved by 2D-NMR, and the absolute quantification of labeled and unlabeled extracellular organic acids was achieved by LC-MS/MS. Although, both strains consume most of the malic acid provided, the “acidic strain” produces de novo malic acid during the second part of the alcoholic fermentation. In addition, 13C-filiation analyses provided evidence that most of the TCA is fed by glycolytic pyruvate and/or by cytosolic acetyl-CoA. Our results also confirmed that malic acid may be a secondary source of TCA cycle during alcoholic fermentation especially in high malic acid consuming strains that has an efficient malo-ethanolic fermentation. Finally, 13C-labeled compounds belonging to amino acids, alcoholic fermentation and neoglucogenesis pathways were identified, highlighting the pleiotropic position of malic acid in both catabolic and anabolic routes.

DOI:

Publication date: February 9, 2024

Issue: OENO Macrowine 2023

Type: Poster

Authors

Vion Charlotte1,2, Bloem Audrey3, Valette Gilles4, Da Costa Gregory2, Richard Tristan2, Camarasa Carole3, Marullo Philippe 1,2

1. Biolaffort, Bordeaux, FRANCE
2. UMR 1366 Œnologie, Université de Bordeaux, INRAE, Bordeaux INP, BSA, ISVV
3. UMR SPO, Univ Montpellier, INRAE, Institut Agro, 34060 Montpellier, France
4. IBMM, Univ Montpellier, CNRS, ENSCM, 34000 Montpellier, France

Contact the author*

Keywords

13C-labeling, malic acid, central carbon metabolism

Tags

IVES Conference Series | oeno macrowine 2023 | oeno-macrowine

Citation

Related articles…

FACTORS AFFECTING QUERCETIN SOLUBILITY IN SANGIOVESE RED WINE: FIRST RESULTS

Quercetin (Q) is present in grape in form of glycosides and as aglycone. These compounds are extracted from grape skins during winemaking. In wines, following the hydrolysis reactions, the amount of quercetin aglycon can exceed its solubility value. Unfortunately, a threshold solubility concentration for quercetin in wine is not easy to determine because it depends on wine matrix (Gambuti et al., 2020).

ANTIOXIDANT CAPACITY OF INACTIVATED NON-SACCHAROMYCES YEASTS

The importance of the non-Saccharomyces yeasts (NSY) in winemaking has been extensively reviewed in the past for their aromatic or bioprotective capacity while, recently their antioxidant/antiradical potential has emerged under winemaking conditions. In the literature the antioxidant potential of NSY was solely explored through their capacity to improve glutathione (GSH) content during alcoholic fermen- tation [1], while more and more studies pointed out the activity of the non-glutathione soluble fraction released by yeasts [2].

SUB-CRITICAL WATER: AN ORIGINAL PROCESS TO EXTRACT ANTIOXIDANTS COMPOUNDS OF WINE LEES

Wine lees are quantitatively the second most important wine by-product after grape stems and marc [1]. In order to recycle, distilleries recovered ethanol and tartaric acid contained in wine lees but yeast biomass is often unused. It has already been demonstrated that this yeast biomass could be upcycled to produce yeast extracts of interest for wine chemical stabilization [2]. In addition, it is well known that lees, during aging, release compounds that preserve wine from oxidation.

INFLUENCE OF THE NITROGEN / LIPIDS RATIO OF MUSTS ON THE REVELATION OF AROMATIC COMPOUNDS IN SAUVIGNON BLANC WINE

Production of volatile compounds by yeast is known to be modulated by must nitrogen. Nevertheless, various parameter of must quality have an impact on yeast fermentation. In this study we propose to evaluate the impact of nitrogen / lipids balance on a Sauvignon Blanc grape juice (Val de Loire).
Must was prepared from the same grapes at pilot scale. Three modalities were carried out: direct pressing, direct pressing with a pre-fermentation cold stabulation and pellicular maceration before pressing.

UNRAVELLING THE ROLE OF LACTIC ACID BACTERIA ON SPARKLING WINE ELABORATION THROUGH METABOLOMICS APPROACH

Xinomavro is a red grape variety from Northern Greece (Protected Designation of Origin), known for the nice acidities, perfectly appropriate for sparkling wine production (Rosé and Blanc de Noir). The elabo- ration of sparkling wine requires technical as well as scientific skills. Although the impact of the yeast strains and their metabolites on the final product quality is well documented, the action of bacteria still remains unknown.
The present work focuses (i) on the population diversity of lactic acid bacteria isolated from sparkling wines and (ii) on the technological effect of the species during sparkling wine elaboration.