Date of Award

December 2020

Document Type


Degree Name

Doctor of Philosophy (PhD)


Chemical Engineering

Committee Member

Mark A. Blenner

Committee Member

Christopher A. Saski

Committee Member

Marc R. Birtwistle

Committee Member

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.



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