OENO IVAS 2019 banner
IVES 9 IVES Conference Series 9 OENO IVAS 9 OENO IVAS 2019 9 Grape and wine microorganisms: diversity and adaptation 9 Flor yeast diversity and dynamics in biologically aged wines

Flor yeast diversity and dynamics in biologically aged wines

Abstract

Wine biological aging is characterized by the development of yeast strains that form a biofilm on the wine surface after alcoholic fermentation. These yeasts, known as flor yeasts, form a velum that protects the wine from oxidation during aging. Thirty-nine velums aged from 1 to 6 years were sampled from “Vin jaune” from two different cellars. 

We show for the first time that these velums possess various aspects in term of color and surface aspects. Surprisingly, the heterogeneous velums are mostly composed of one species, S. cerevisiae. Scanning electron microscope observations of these velums revealed unprecedented biofilm structures and various yeast morphologies formed by the sole S. cerevisiae species. Our results highlight that different strains of Saccharomyces are present in these velums. Unexpectedly, in the same velum, flor yeast strain succession occurred during aging, supporting the assumption that environmental changes are responsible for these shifts. Despite numerous sample wine analyses, very few flor yeasts could be isolated from wine following alcoholic fermentation, suggesting that flor yeast development results from the colonization of yeast present in the aging cellar. We analyzed the FLO11 and ICR1 sequence of different S. cerevisiae strains in order to understand how the same strain of S. cerevisiae could form various types of biofilm. Among the strains analyzed, some were heterozygote at the FLO11 locus, while others presented two different alleles of ICR1 (wild type and a 111 bp deletion). We could not find a strong link between strain genotypes and velum characteristics. The same strain in different wines could form a velum having very different characteristics, highlighting a matrix effect.

DOI:

Publication date: June 23, 2020

Issue: OENO IVAS 2019

Type: Article

Authors

Hervé Alexandre, Vanessa David-Vaizant 

AgroSup Dijon, PAM UMR A 02.102, Université Bourgogne Franche-Comté, Dijon, France, 2 Equipe VAlMiS, Institut Universitaire de la Vigne et du Vin, Dijon, France 

Contact the author

Keywords

flor yeast, FLO11, Saccharomyces cerevisiae, Vin Jaune

Tags

IVES Conference Series | OENO IVAS 2019

Citation

Related articles…

Twenty-two shades of grey – An analysis of alcohol regulations in the Arab world

This article compares alcohol regulations across 22 Arab League member countries.

Corvina and Corvinone grape berries grown in different areas and their aptitude to postharvest dehydration

The Valpolicella area (Veneto Region, Italy) is famous for its high quality wines: Amarone and Recioto, both obtained from partial post-harvest dehydrated red grapes.

Rară Neagră 2.0: prospecting, improving and safeguarding the biodiversity in an eastern european heritage grape variety

The Rară Neagră 2.0 project aims to restore and safeguard the intra-varietal diversity of the ancient Eastern European grape variety Rară Neagră through polyclonal selection and the establishment of a certified genetic conservatory.

Multivariate characterization of Italian monovarietal red wines using FTIR spectroscopy

The assessment of wine authenticity is of great importance for consumers, producers and regulatory agencies to guarantee the geographical origin of wines and grape variety as well. Since mid-infrared (MIR) spectroscopy with chemometrics represent a suitable tool to ascertain the wine composition, including features associated with the polyphenolic compounds, the aim of this study was to generate MIR spectra of red wines to be exploited for classification of red wines based on the relationship between grape variety and wine composition. Several multivariate data analyses were used, including Principal Component Analysis (PCA), Discriminant Analysis (DA), Support Vector Machine (SVM), and Soft Intelligent Modelling of Class Analogy (SIMCA).

Unravel the underlying mechanisms of delaying ripening techniques in grapevine

In a scenario of changing climate conditions, grapevine is significantly affected at multiple levels. Advancements in phenology and berry ripening, however, are the major dynamics of the generalized increase in average temperature and evaporative demand, negatively affecting berry quality and productivity. The aim of this work was to unravel the underlying mechanisms of bunch-zone auxin application (NAA; 1-Naphthaleneacetic acid) and source-limiting canopy management approaches in delaying berry ripening. In randomized block design experiments, control vines were compared to vines treated with NAA, subjected to apical-to-bunch defoliation or antitranspirant application (n=10-to-42 plants per treatment).