Modified E. coli for Enhanced Production of Pyruvate, Ethanol
Pyruvate is a starting material for synthesizing a variety of biofuels and chemicals. It can be readily converted into more than 60 commercial chemicals, including ethanol and several active pharmaceutical ingredients. Pyruvate is also an important component in many food additives, weight loss agents and antiaging skin treatments.
Industrial methods for producing pyruvate are toxic, energy intensive and depend on a byproduct of the wine industry. Microbial fermentation is a cheap and viable alternative with estimated savings up to ~85 percent. To date the process has relied primarily on two microorganisms – a T. glabrata yeast and an E. coli mutant – but there is interest in engineering efficient new strains to increase savings even further.
UW–Madison researchers have developed a variety of new E. coli strains capable of producing pyruvate up to 95 percent of the maximum theoretical yield from renewable sources under aerobic conditions. This exceeds the highest previously reported yields of 78 percent.
The researchers used a genome-scale metabolic model of E. coli to identify multiple gene deletion targets that couple growth rate with pyruvate production. Further engineering of these new strains enabled them to produce ethanol at near maximum theoretical yields.
- Cheaper and more efficient pyruvate production
- “Greener” bio-based alternative (coupled with cost savings from conventional solvent production)
- Fermentative route is biomass derived and offers a less carbon-intensive approach while still providing cost savings compared to traditional methods.
- New strains outperform competitors by more than double digits (95 vs 78 percent of max. theoretical yield).
- E. coli is a robust, industrially accepted and widely used biocatalyst for high value products.
- Efficient and economical production of pyruvate and other commodity chemicals