UC Davis

As our society increases its demand for natural sugars in the food and health industry, we need to establish alternative methods for the sustainable and economical production of these chemical commodities. Over the last 30 years, Escherichia coli has emerged as a malleable micro-organism that can be engineered as an efficient whole cell catalyst for chemical production. The first chapter of this thesis describes the establishment of E. coli as a heterotrophic production host and provides a brief overview of compounds that are commonly produced in this organism. To overcome the limitations of compound extraction, difficulties in using traditional total synthesis schemes, and costly in-vitro enzymatic processes to produce carbohydrates, the second and third chapters describe the development of metabolic engineering strategies for a fucosylated human milk oligosaccharide, lactodifucotetraose (LDFT), and a rare sugar D-psicose. Lastly, the appendix discusses the characterization of mutations acquired during adaptive laboratory evolution processes that enhances E. coli’s tolerance towards isobutyl acetate.