In the prospect of a bio-based economy, the use of biomass as source of hydrocarbons relies on the development of bioprocesses for the production of fuels and chemicals. Lignocellulosic material will be adopted as a source of sugars to be converted to ethanol, other energy carriers and to a portfolio of chemicals. Regardless of the product, robust microorganisms are a prerequisite for the feasibility of lignocellulose bioconversion, where microorganisms are facing tremendous challenges including high concentrations of fermentation inhibiting molecules, such as organic acids and phenolic compounds. In the proposed project we will engineer the yeast cell membrane to reduce its permeability to lignocellulose-derived inhibitors, specifically organic acids and phenolic compounds, with the final goal of obtaining more robust strains with reduced permeability to inhibitory compounds. Membrane simulations will be used to predict the effect on the physico chemical properties of S. cerevisiae membrane in which alternative lipids species, known to confer rigidity and reduce permeability in Archaea, acetic acid bacteria and the food spoilage yeast Z. bailii are incorporated. These results will guide metabolic engineering strategies to engineer novel strains containing the most promising lipid species. The new strains will be characterised for their tolerance and membrane permeability to organic acids and phenolic compounds and this will be correlated to their novel membrane composition.
Professor vid Chalmers, Biology and Biological Engineering, Industrial Biotechnology
Funding Chalmers participation during 2017–2020