Catégorie | Transversal |
Période | 2026-2030 (AAP2) |
Porteur | SCHWARTZ Mathieu |
Unités/Plateformes BFC | PAM, ICB / DIVVA, 2B2S |
Collaborateurs externes |
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Doctorants/Postdoctorants | 1 doctorant(e) |
Stages Master | 2 |
Work Packages HARMI | WP3, WP4 |
Volatile thiols are key contributors to wine aroma, yet they remain mostly bound under non-volatile conjugated forms (e.g., Cys-4MMP, Cys-3MH), limiting their sensory impact. This project aims to identify and design new exogenous enzymes capable of releasing these aroma compounds in wine at the post-fermentation step. The ultimate objective is to valorize the sulfur-rich aroma potential naturally present in wine by leveraging microbial biodiversity and enzymatic engineering.
To achieve this, we will first perform a metagenomic mining of microbial niches known or suspected to harbor sulfur-transforming activities. These include:
(i) the oral microbiota of high-sulfur producing individuals,
(ii) microbiomes from grape musts, and
(iii) sulfur-rich extreme environments.
With the help of the 2B2S bioinformatics platform (Besançon), we will screen gene families involved in C–S bond cleavage in metagenomic resources corresponding to high sulfur-producing microbial niches. Candidate enzymes will be modeled in 3D at the atomistic level using integrative structural biology tools developed by the “Physics Applied to Proteins” group (ICB, Dijon), focusing on active-site features such as hydrophobic loops known to promote thiol release.
The most promising enzymes will be expressed recombinantly in food-grade systems by the UMR PAM (PCAV team) and UMR ICB. Biochemical and structural characterization will follow, assessing activity, specificity, and robustness under wine-like conditions. The effectiveness of the enzymes in releasing aroma-relevant thiols will be evaluated using analytical approaches on the DIVVA platform (UMR PAM), specialized in wine quality assessment especially wine thiols.
This project directly addresses HARMI’s goals by combining molecular microbiology, microbial protein engineering, oenology, and bioprocess innovation, to develop new biotechnological tools valorizing microbial ecosystems for improving fermented food quality. It opens new avenues for precision oenology, through post-fermentation modulation of wine aroma.
