(578c) Towards the Valorization of Waste-Stream Feedstocks into Value-Added Chemicals Using Genetically Engineered Yeasts

The fields of synthetic biology and metabolic engineering aim at reprogramming microbes to be used in a multitude of applications. To this end, we are engineering yeasts towards the valorization of potato starch obtained from food waste streams to produce chemicals of industrial interest. Ongoing work includes engineering the model yeast Saccharomyces cerevisiae for digestion and utilization of pure potato starch. This will be followed by strain and enzyme engineering efforts for improving efficiency of starch digestion such as enhancing enzyme secretion, in addition to enzyme copy number variation and directed evolution. Furthermore, the engineered strains will be characterized with a minimally processed potato-based feedstock obtained from waste streams as the main carbon source for sustaining cell growth. Finally, in an effort to contribute towards a meaningful circular bioeconomy through yeast fermentation of our feedstock, we will explore the use of the engineered starch-degrading strains to produce industrially relevant molecules. Examples of these molecules include the building blocks adipic acid and polyhydroxyalkanoates (market size of ~5 billion and ~80 million USD, respectively) as well as amino acids that could be used for human and animal feed (market size of ~30 billion USD).