Characterizing the metabolic phenotype: A phenotype phase plane analysis

Jeremy S. Edwards*, Ramprasad Ramakrishna, Bernhard O. Palsson

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

114 Citations (Scopus)


Genome-scale metabolic maps can be reconstructed from annotated genome sequence data, biochemical literature, bioinformatic analysis, and strain-specific information. Flux-balance analysis has been useful for qualitative and quantitative analysis of metabolic reconstructions. In the past, FBA has typically been performed in one growth condition at a time, thus giving a limited view of the metabolic capabilities of a metabolic network. We have broadened the use of FBA to map the optimal metabolic flux distribution onto a single plane, which is defined by the availability of two key substrates. A finite number of qualitatively distinct patterns of metabolic pathway utilization were identified in this plane, dividing it into discrete phases. The characteristics of these distinct phases are interpreted using ratios of shadow prices in the form of isoclines. The isoclines can be used to classify the state of the metabolic network. This methodology gives rise to a "phase plane" analysis of the metabolic genotype-phenotype relation relevant for a range of growth conditions. Phenotype phase planes (PhPPs) were generated for Escherichia coli growth on two carbon sources (acetate and glucose) at all levels of oxygenation, and the resulting optimal metabolic phenotypes were studied. Supplementary information can be downloaded from our website (

Original languageEnglish
Pages (from-to)27-36
Number of pages10
JournalBiotechnology and Bioengineering
Issue number1
Publication statusPublished - 5 Jan 2002


Dive into the research topics of 'Characterizing the metabolic phenotype: A phenotype phase plane analysis'. Together they form a unique fingerprint.

Cite this