Pyruvate and phosphoenol-pyruvate (PEP) are two central intermediates in cellular metabolism. They are the branch points of many catabolic and biosynthetic pathways. Although the importance of these intermediates has long been recognized, the use of both genetic and engineering techniques for studying the physiological effect of redirected pyruvate and PEP metabolism has not been reported. Pyruvate is not normally recycled back to PEP under glycolytic conditions. Because of this irreversibility, the yields of many specialty chemicals produced from glucose via bacterial fermentations remain low. The Principal Investigator proposes to construct and characterize strains of the bacteria E. coli which can recycle pyruvate back to PEP. In addition to improving the yields of amino acid fermentations, the results of this project could contribute to the understanding of how the cell distributes its carbon source, and how to decouple product formation from cell growth.
