Date of Award
Doctor of Philosophy (PhD)
Mark A. Blenner
Christopher A. Saski
Marc R. Birtwistle
Eric M. Davis
Oleaginous yeasts have long been a target for developing industrial-scale biorefineries due to their ability to accumulate high amounts of lipids, synthesize complex chemicals and proteins, and robustly metabolize diverse feedstocks. In parallel, interest in lignocellulosic biomass as a feedstock has grown. While most processes focus on the carbohydrates from cellulose and hemicellulose, the most energy-dense biopolymer, lignin, remains underutilized.
This dissertation describes foundational work describing lignin conversion by Cutaneotrichosporon oleaginosus, a non-model oleaginous yeast known for its metabolism of alternative sugars, including xylose, and tolerance and metabolism toxic lignocellulosic hydrolysate inhibitors such as 5-HMF, furfural, acetic acid. This dissertation is the first to describe robust lipid production by this yeast while utilizing five aromatic substrates as the sole carbon source: phenol, resorcinol, p-hydroxybenzoic acid, p -coumaric acid, and ferulic acid. This yeast can also tolerate an alkaline pretreated lignin hydrolysate and remain oleaginous.
The genetic basis of yeast aromatic metabolism is poorly characterized, so a multi-omic approach was applied to improve the existing genome annotation and identify novel gene functions relevant to aromatic catabolism. Genes unique to and common across all six substrates mentioned build a roadmap for future engineering for robust lignin valorization. To this, a small, functional genetic toolkit was developed to improve the genetic accessibility of this non-model yeast. Together, this dissertation demonstrates that C. oleaginosus is poised to become a preferred host for lignocellulosic biomass to oleochemical conversion.
Yaguchi, Allison, "Development of Cutaneotrichosporon oleaginosus to Convert Lignin-Derived Phenolics to Oleochemicals" (2020). All Dissertations. 2755.