Diversity of oligopeptide transport in industrial yeasts

Academic partners: INRA, Montpellier, France; UMINHO, Braga, Portugal
Industry Partner : Pernod-Ricard, France

In wine-making fermentations nitrogen is a key nutrient, affecting both fermentation kinetics and the formation of wine aroma. Grape juice is mainly composed of ammonium and amino acids and these are utilized as the main nitrogen source by yeast. Oligopeptides represent a substantial nitrogen resource for microorganisms in grape must as well as in different environments. Various families, including the recently identified FOT transporters can coexist in microorganisms but there is a lack of knowledge about oligopeptide transport and its regulation. This project will identify and characterize oligopeptide transporters in Saccharomyces and in non-conventional yeast commonly found in food ecosystems and determine their impact on yeast fermentative performances. Genomic analysis, RT-PCR, phenotyping microarray and fluorescence-based competitive uptake (F-CUp) assay as well as 14C analysis will be performed to characterize the diversity of oligopeptide transporters and their specificity. The impact of these transporters on fermentation performance, nitrogen consumption and flavour production will be investigated using dedicated robotic and analytic platforms and will be assessed at pilot scale under industry conditions.