Etudiant-Jobs in Frankreich

Climate change is reshaping the wine industry. Warmer conditions lead to grapes with higher sugar and lower acidity, resulting in wines with higher alcohol levels and reduced freshness. These shifts can cause microbial and sensory imbalances, challenging the stability and quality of wines.

During alcoholic fermentation, Saccharomyces cerevisiae converts grape sugars into ethanol and CO₂ while producing a variety of metabolites that influence wine character. Among them, organic acids, derived from the central carbon metabolism (CCM), play a key role in acidity, flavor perception, and the progress of malolactic fermentation. Understanding how yeast genetics shape this metabolic network could offer new solutions for climate adaptation in oenology.

This project aims to validate the genetic determinants underlying variations in the production of organic acids, particularly succinic acid, in S. cerevisiae identified by a genome-wide association study (GWAS) conducted on more than yeast strains (in collaboration with UMR GMGM, Prof. J. Schacherer).

Candidate validation will be performed through allelic replacement using CRISPR-Cas9 (96– genetic constructs). Engineered strains will be phenotyped under oenological conditions using micro- and tube-scale fermentations in synthetic grape must. Growth and metabolite production will be monitored via optical density and HPLC respectively. The most relevant strains (~30) will be further characterized at a larger scale using automated fermenters, enabling detailed kinetic and metabolic profiling.

This work will provide new insights into the genetic basis of yeast metabolic diversity, offering perspectives for adapting fermentation processes to climate change and improving wine balance and quality.

Nous recherchons un / une étudiant(e) en dernière année d’école d’ingénieur ou en M2 en microbiologie, génie biologique ou biotechnologies. Le / la candidat(e) devra au minimum maîtriser la théorie et la pratique en génie biologique (travail en conditions stériles, transformation de levure / bactéries, extraction d’ADN, construction de plasmide, traitement des données). Il / Elle devra également faire preuve d’une bonne capacité rédactionnelle et de synthèse (rapports bibliographiques et rapports d’expérience). Enfin, nous recherchons avant tout une personne forte de proposition avec une bonne capacité d’apprentissage et d’adaptation.

Dès que possible