BioREFINE-2G project – Engineering of industrial yeast strains for production of dicarboxylic acids from side and waste streams

For our future we need to assure that fuels as well as chemicals will be produced environmentallyfriendly from renewable resources. There must be a major move away from the use of food biomasstowards the use of renewable non-food feed-stocks, such as wood, stover, straw etc. The existing 2nd generation biorefineries utilize less than 20% of the biomass feedstock for ethanol production. Major side-streams are produced such as pentose and lignin waste streams that are used for biogas and energy production. Converting the carbon from these waste streams into added-value products would improve the environmental benefits of the biorefineries. The BioREFINE-2G project aims at the development of genetically modified industrial Saccharomyces cerevisiae strains suitable for the production of the selected dicarboxylic acids from side and waste streams rich in C5 sugar andmixtures of C5/C6 sugars. The target compounds can be polymerised to biodegradable polymersthat can find application as plastics, coatings or adhesives. To reach the goals, the identification of relevant metabolic routes, strain engineering and the development of a toolbox for manipulation of industrial S. cerevisiae strains are required. Here, we present advanced genetic engineering tools applicable for generally hardly amenable strains with industrial background. This involves tools forstable heterologous gene (over-)expression and a strategy for fast performance of gene disruption inmultiple ploidy strains. The use of the developed toolbox in metabolic engineering of various industrial yeast strains will be demonstrated.