Profiling Yarrowia lipolytica for Growth and Engineering on <C3 Carbon Intermediates

• Meredith Rodney, Chemical Engineering, University of Delaware

• Kevin Solomon, Department of Chemical and Biomolecular Engineering, University of Delaware

Atmospheric carbon dioxide is a primary cause of climate change leading to ecosystem problems and increased global warming. Many current carbon capture approaches have a limited conversion of carbon gas, are economically infeasible, or have a limited ability to address climate problems at scale. Cell-based electro-bioconversion is one solution for carbon capture that is more promising.  Atmospheric CO2 is converted into carbon compounds using electrocatalysis and used as a feedstock which supports cell growth. The disadvantages are less than C3 intermediates (abbr. <C3) have a limited energy potential and inhibit cellular ability to produce complex molecules. 

Yarrowia lipolytica is a yeast species known to grow on a variety of carbon sources and displays potential pathways for these carbon compounds. Through RNA sequencing, the transcriptional response of engineered strains of Y. lipolytica to varying carbon media types can be identified. Knowing the critical pathways for carbon consumption and toxicity response for <C3 compounds will identify genetic targets for strain optimization. Current engineered strains of this yeast create beta-carotene, an orange pigment and antioxidant used in many commercial products. Beta-carotene has been shown to have limited production on yeast media containing formate, ethanol, acetate, and n-propanol, informally labeled as FEAP. To enable growth on these <C3 carbon sources, the Y. lipolytica strains were tested on minimal media by varying the concentration of these carbon sources. Preliminary results indicate that the wild-type of Y. lipolytica performs the best and two of the engineered strains tolerate this feedstock. Based on these findings, mRNA extraction and sequencing will be used to understand how wildtype and engineered strains of Y. lipolytica respond to carbon feedstock in order to identify genetic targets for strain improvement. This information is critical to develop carbon capture pathways in cell cultures and improve the output of value-added products from CO2 waste.