Metabolic evolution of energy-conserving pathways for succinate production in Escherichia coli.

ABSTRACT: During metabolic evolution to improve succinate production in Escherichia coli strains, significant changes in cellular metabolism were acquired that increased energy efficiency in two respects. The energy-conserving phosphoenolpyruvate (PEP) carboxykinase (pck), which normally functions in the reverse direction (gluconeogenesis; glucose repressed) during the oxidative metabolism of organic acids, evolved to become the major carboxylation pathway for succinate production. Both PCK enzyme activity and gene expression levels increased significantly in two stages because of several mutations during the metabolic evolution process. High-level expression of this enzyme-dominated CO(2) fixation and increased ATP yield (1 ATP per oxaloacetate). In addition, the native PEP-dependent phosphotransfe

SUBMITTER: Zhang X 

PROVIDER: S-EPMC2777959 | biostudies-literature | 2009 Dec

REPOSITORIES: biostudies-literature