The E. coli NOG Strain

The Embden-Meyerhoff-Parnas (EMP) pathway, commonly known as glycolysis, represents the fundamental biochemical infrastructure for sugar catabolism in almost all organisms, as it provides key components for biosynthesis, energy metabolism, and global regulation. The EMP-based metabolism synthesizes three-carbon (C3) metabolites before two-carbon (C2) metabolites, and emits one CO2 in the synthesis of the C2 building block, acetyl-CoA, which is the precursor for many industrially important products. 

Using rational design, genome editing, and evolution, we replaced the native glycolytic pathways in Escherichia coli with the previously designed non-oxidative glycolysis (NOG), which bypasses initial C3 formation and directly generates stoichiometric amounts of C2 metabolites. 

The resulting strain, which contains 11 gene overexpressions and 10 gene deletions by design, and more than 50 genomic mutations (including 3 global regulators) through evolution, grows only aerobically in glucose minimal medium, but can ferment anaerobically to products with nearly complete carbon conservation. This re-designed E. coli strain represents a different approach for carbon catabolism, and may serve as a useful platform for bioproduction.