Poster Presentation 2-38

Uncoupling of Glycolysis from Biomass Production in Microorganisms

Brian J. Koebmann, Søren Helmark and Peter R. Jensen^*

BioCentrum-DTU

Technical University of Denmark

Building 301

DK-2800 Kgs. Lyngby, Denmark

Phone: +45 45252510

Fax: +45 45932809

E-mail: prj@biocentrum.dtu.dk

One way to improve the efficiency of fermentation processes is to uncouple product formation from biomass production by introducing an additional ATP consuming reaction. We have overexpressed, in Escherichia coli and Lactococcus lactis, the F₁-part of the (F₁F₀) H⁺-ATPase and shown that this leads to increased ATP turnover. Using libraries of synthetic promoters with different strengths we were able to modulate the uncoupled ATPase activity to different extents. The ratio of product to biomass production increased in both organisms with increasing ATPase expression. In steadily growing E. coli the biomass yield on glucose decreased by 55% and the yield of acetate increased by 40%. The glycolytic flux could be stimulated by 70% and acetate flux increased by 220%. In non-growing cells of L. lactis the glycolytic flux was almost doubled by the ATPase activity. The approach for uncoupling glycolysis from biomass production holds strong promises for increasing the efficiency and productivity of bacteria and yeasts used for industrial production of numerous organic compounds.