Carbon flux analysis in a pantothenate overproducing Corynebacterium glutamicum strain.
Carbon flux analysis during a pseudo-stationary phase of metabolite accumulation in a genetically engineered strain of Corynebacterium glutamicum, containing plasmids leading to over-expression of the ilvBNCD and panBC operons, has identified the basic metabolic constraints governing the potential of this bacterium to produce pantothenate. Carbon flux converging on pyruvate (75% of glucose uptake) is controlled by anabolic precursor requirements and NADPH demand provoking high carbon loss as CO2 via the pentose pathway. Virtually all the flux of pyruvate is directed into the branched pathway leading to both valine and pantothenate production, but flux towards valine is tenfold higher than that transformed to pantothenate, indicating that significant improvements will only be obtained if carbon flux at the ketoisovalerate branchpoint can be modulated.
Chassagnole
Christophe
C
Laboratoire Biotechnologie-Bioprocédés, UMR INSA/CNRS N5504 & UMR INSA/INRA 792, Centre de Bioingénierie Gilbert Durand, Institut National de Sciences Appliquées, Toulouse, France. chassagnole@insa-tlse.fr
Létisse
Fabien
F
Diano
Audrey
A
Lindley
Nic D
ND
D002244:Carbon / Q000378:metabolism*; D002952:Citric Acid Cycle; D003352:Corynebacterium / Q000235:genetics / Q000378:metabolism*; D010205:Pantothenic Acid / Q000096:biosynthesis*; D019289:Pyruvic Acid / Q000378:metabolism
D010205:Pantothenic Acid; D002244:Carbon; D019289:Pyruvic Acid