Enhancing organic acid tolerance in the yeasts Zygosaccharomyces (para)bailii and Kluyveromyces marxianus

Academic partners: University of Bicocca, Milano, Italy; UCC, Cork, Ireland
Industry Partner: NOVAMONT, Italy

This project explores the impact of combinatorial stresses encountered under industrial conditions in two very promising yeast cell factories, Z. (para)bailii and K. marxianus. Elucidating the molecular mechanisms underpinning their ability to counteract stresses will promote more efficient use of these yeasts in industrial processes. To reach this goal, physiological (FITR, single cell flow cytometry, intracellular biosensors) and molecular (RNASeq) measurements will be coupled. A parallel strategy will apply adaptive laboratory evolution (ALE) to select strains with improved growth on industrial substrates. Once the tolerance determinants and the mutations predicted to confer enhanced tolerance are identified, synthetic biology tools (CRISPR-Cas; in vitro and in vivo assembly) will then be used to describe the networks contributing to robustness and to construct novel yeast strains with enhanced growth and performance. These prototype yeasts will be tested in large-scale fermentors at the industry partner to allow comparison of fermentation performance at laboratory and commercial scales.