Olson DG Hörl M Fuhrer T Cui J Zhou J Maloney MI Amador-Noguez D Tian L Sauer U Lynd LR 2017 The metabolism of Clostridium thermocellum is notable in that it assimilates sugar via the EMP pathway but does not possess a pyruvate kinase enzyme. In the wild type organism, there are three proposed pathways for conversion of phosphoenolpyruvate (PEP) to pyruvate, which differ in their cofactor usage. One path uses pyruvate phosphate dikinase (PPDK), another pathway uses the combined activities of PEP carboxykinase (PEPCK) and oxaloacetate decarboxylase (ODC). Yet another pathway, the malate shunt, uses the combined activities of PEPCK, malate dehydrogenase and malic enzyme. First we showed that there is no flux through the ODC pathway by enzyme assay. Flux through the remaining two pathways (PPDK and malate shunt) was determined by dynamic 13C labeling. In the wild-type strain, the malate shunt accounts for about 33±2% of the flux to pyruvate, with the remainder via the PPDK pathway. Deletion of the ppdk gene resulted in a redirection of all pyruvate flux through the malate shunt. This provides the first direct evidence of the in-vivo function of the malate shunt. application/pdf https://sonar.ch/global/documents/136888 eng info:eu-repo/semantics/altIdentifier/doi/10.1016/j.ymben.2016.11.011 info:eu-repo/semantics/altIdentifier/pmid/27914869 info:eu-repo/semantics/openAccess Metabolic engineering. - 2017 (13)C flux analysis Malate dehydrogenase Malate shunt Malic enzyme Oxaloacetate decarboxylase Pyruvate kinase Biosynthetic Pathways Carbon-13 Magnetic Resonance Spectroscopy Clostridium thermocellum Glucose Glycolysis Malates Metabolic Flux Analysis Metabolic Networks and Pathways Models, Biological Phosphoenolpyruvate Pyruvate Kinase Pyruvic Acid Glycolysis without pyruvate kinase in Clostridium thermocellum. http://purl.org/coar/resource_type/c_6501