Understanding, mapping and engineering xylose signaling in industrially relevant yeast species

The yeast cell factory Saccharomyces cerevisiae has been engineered to use xylose, a five-carbon sugar that prevails in major types of lignocellulosic substrates used in biorefineries.

However, xylose consumption is an order of magnitude lower than glucose consumption, which directly impacts the process efficiency and economy.

As xylose leads to dysfunctional sugar signaling in S. cerevisiae cells, the present study uses an interspecies approach to unravel and engineer the mechanisms for xylose sensing in yeast.

For this purpose, a combination of methodologies such as fluorescent biosensors, metabolomics and RNAseq will be used to identify metabolic intermediates triggering the intracellular sugar sensing in S. cerevisiae, map the xylose sensing routes and mechanisms in yeast species that naturally use xylose, and use the acquired knowledge to provide S. cerevisiae with the missing signaling mechanisms on xylose.

This 4-year PhD project will be performed at Lund University, at the Division of Applied Microbiology and in collaboration with the metabolomics platform at the Center for Analysis and Synthesis.

The project is expected to generate fundamental knowledge on sugar sensing mechanisms and their link to the primary metabolism while also providing novel solutions to improve any biotech process where lignocellulose is used as a carbon source.

The identification of useful clues for diseases associated with metabolic disorders in higher eukaryotes is also foreseen.