Date of Award:


Document Type:


Degree Name:

Master of Science (MS)


Biological Engineering

Committee Chair(s)

Jixun Zhan


Jixun Zhan


Ron Sims


Anhong Zhou


Justin Jones


Curcumin is a bright orange compound with myriad applications for human health and wellness. Curcumin occurs naturally in the plant Curcuma longa (commonly known as turmeric) but must be extracted from the roots in an environmentally unfriendly fashion to obtain commercially relevant amounts of the compound. In addition, extraction of curcumin from turmeric spice yields a mixture of various curcuminoids, presenting an issue for isolating it in its pure form and complicating its use in clinical settings.

Heterologous biosynthetic production of curcumin in Escherichia coli has been used extensively as a viable alternative to plant extraction but suffers from poor yield. This thesis describes the application of various upstream biological engineering methods for enhancing the production of curcumin in an engineered E. coli platform. Among these, the enzyme combination for achieving curcumin biosynthesis is optimized, including the use of bacterial and plant enzymes for improving the overall yield. Since curcumin is mainly produced as an intracellular metabolite with cytotoxic effects on the production host, the use of a handful of transferases that can improve curcumin water solubility is also explored to improve excretion from the cell.

These approaches led to the establishment of an efficient curcumin biosynthetic pathway, the identification of several feruloyl-CoA synthases (FCSs) that may be used in place of 4-coumarate-CoA ligase (4CL), and methods for improving curcumin excretion from the cell together with more bioavailable curcumin derivatives. We also discuss the use of a bacterial long-chain fatty acid-CoA ligase for the efficient production of a curcuminoid known as dicinnamoylmethane.