Genetic Determinants of Carbon Metabolism Adaptation in Saccharomyces cerevisiae Host laboratory: This six-month master’s internship will begin in early 2026 and will take place at the UMR SPO (Sciences pour l’Œnologie), within the LIGEM team (Yeasts: Interaction, Genetics, Ecology and Metabolism), located on the Institut Agro Montpellier campus. Supervisors : - Virginie Galeote, Research Scientist (INRAE) : virginie.galeote@inrae.fr - Hugo Devillers, Bioinformatics Research Engineer : hugo.devillers@inrae.fr - Coline Nazet, PhD student (INRAE) : coline.nazet@inrae.fr Project description: 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 500 yeast strains (in collaboration with UMR GMGM, Prof. J. Schacherer). Candidate validation will be performed through allelic replacement using CRISPR-Cas9 (96–192 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. Keywords: yeast, microbiology, molecular biology, genetics, CRISPR-Cas9, phenotyping Main methodologies: Microbiology (cell culture), molecular biology (nucleic acid extraction, yeast/bacteria transformation, plasmid construction), fermentation implementation and monitoring, analytical methods (HPLC), statistical data analysis (R), etc. Internship conditions -Duration: 6 months -Location: UMR SPO, Institut Agro Montpellier (La Gaillarde campus) Candidate profile: Applicants should have basic knowledge of microbiology (sterile techniques), molecular biology, and some experience or interest in data analysis using R. Virginie GALEOTE Chargée de Recherches / Research Scientist Equipe LIGEM (Levures : Interactions, Génétique, Écologie et Métabolisme) INRAE, UMR1083 Sciences pour l’oenologie Bat 28, 2 place Pierre Viala 34060 Montpellier cedex 02 France Tél. : +33 (0)4 99 61 21 10/ +33 (0)6 66 69 44 28 Fax : +33 (0)4 99 61 28 57 http://ww6.montpellier.inra.fr/spo/ Virginie Galeote (to subscribe/unsubscribe the EvolDir send mail to golding@mcmaster.ca)