(337bg) Evolving Yarrowia Lipolytica for Waste Mannitol Utilization

The sugar alcohol mannitol is a primary carbon source found in multiple waste streams, particularly plant-based waste. As a result, there is great potential in valorizing this carbon found in waste streams. However, very few organisms are able to grow on mannitol and utilize this sugar alcohol as a primary carbon source. To address these limitations, we evolved the oleaginous yeast Yarrowia lipolytica for enhanced utilization and conversion of mannitol. Evolved strains exhibited cell densities five-times higher than the control strain when cultivated on mannitol minimal media along with commensurate increases in mannitol consumption rates. Transcriptomics and genomic analysis were used to elucidate the underlying cause for this phenotype. As a demonstration of valorization potential, the evolved mannitol-consuming Y. lipolytica was cultivated on a mannitol-rich Olive Mill Wastewater. These results demonstrate the valorization of this waste stream into lipid products.