Exploring the Glucose Transport System of Torulaspora delbrueckii: Genomic and Functional Characterization

The fermentative capacity of yeasts largely depends on how efficiently they transport sugars into the cell, a step that is often considered rate-limiting in sugar metabolism. While glucose transport has been extensively studied in Saccharomyces cerevisiae, less is known about Torulaspora delbrueckii’s, despite its growing industrial relevance. T. delbrueckii contributes positively to flavour and aroma and displays high stress tolerance in bread and wine fermentations, but the mechanisms behind its sugar uptake are still not well understood. The characterization of its sugar transport system is fundamental to improve its performance in fermentative processes.

In this context, we have been characterizing T. delbrueckii glucose transporters and their transport kinetics. Analysis of the genomes of 41 strains allowed to identify potential glucose transporter genes. Besides the previously characterized Lgt1 and Igt1, at least four additional transporters were found across all strains and their expression throughout the fermentation process is being studied. Furthermore, we are exploring whether it is possible to improve the fermentative capacity of T. delbrueckii by expressing the most ethanol-resistant S. cerevisiae transporters, addressing a key limitation of T. delbrueckii transporters, which are more sensitive to ethanol and therefore contribute to its lower fermentative performance compared to S. cerevisiae.