Mapping photoautotrophic metabolism with isotopically nonstationary (13)C flux analysis

Metab Eng. 2011 Nov;13(6):656-65. doi: 10.1016/j.ymben.2011.08.002. Epub 2011 Sep 1.


Understanding in vivo regulation of photoautotrophic metabolism is important for identifying strategies to improve photosynthetic efficiency or re-route carbon fluxes to desirable end products. We have developed an approach to reconstruct comprehensive flux maps of photoautotrophic metabolism by computational analysis of dynamic isotope labeling measurements and have applied it to determine metabolic pathway fluxes in the cyanobacterium Synechocystis sp. PCC6803. Comparison to a theoretically predicted flux map revealed inefficiencies in photosynthesis due to oxidative pentose phosphate pathway and malic enzyme activity, despite negligible photorespiration. This approach has potential to fill important gaps in our understanding of how carbon and energy flows are systemically regulated in cyanobacteria, plants, and algae.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Autotrophic Processes*
  • Carbon / metabolism*
  • Carbon Isotopes / metabolism*
  • Isotope Labeling / methods
  • Malate Dehydrogenase / metabolism
  • Pentose Phosphate Pathway
  • Phototrophic Processes*
  • Synechocystis / metabolism


  • Carbon Isotopes
  • Carbon
  • Malate Dehydrogenase