The underlying goals of this project are to expand the number and diversity of conventional petrochemical replacements that can be derived from renewable resources, while also developing the tools and understanding needed to do so at high levels and in an economical and sustainable manner. Through rational re-design of their metabolism and the development of novel enzyme pathways, microorganisms can be engineered to produce a multitude of useful chemicals. However, despite their promise, these microbial chemical factories are commonly inhibited by those same species that they have been engineered to produce. This project will first explore the modular engineering of a network of non-natural pathways for the biosynthesis of four aromatic products: styrene, (S)-styrene oxide, (R)-styrene glycol, and 2-phenylethanol. To counter their inhibitory effects, strategies will also be explored to improve tolerance and productivity by actively excreting toxic products from cells as they are synthesized. To do so, we will screen comprehensive libraries of native and heterologous efflux transporters - both individually and in a combinatorial manner - to identify those imparting aromatic tolerance. Uniquely, we will explore the potential role of synergy between different classes of inner membrane and transmembrane RND efflux pumps and its importance for clearing toxic molecules from the intracellular milieu. Finally, to preserve host fitness, a suite of aromatic-inducible gene circuits will be engineered to control efflux transporter expression only if and when needed by the cell. These collective efforts will open the door to new and useful renewable chemicals, while supporting their production at the highest possible output.
|Effective start/end date||6/15/15 → 8/31/19|
- National Science Foundation (NSF): $378,000.00