Cellular Growth Arrest and Persistence from Enzyme Saturation

PLoS Comput Biol. 2016 Mar 24;12(3):e1004825. doi: 10.1371/journal.pcbi.1004825. eCollection 2016 Mar.


Metabolic efficiency depends on the balance between supply and demand of metabolites, which is sensitive to environmental and physiological fluctuations, or noise, causing shortages or surpluses in the metabolic pipeline. How cells can reliably optimize biomass production in the presence of metabolic fluctuations is a fundamental question that has not been fully answered. Here we use mathematical models to predict that enzyme saturation creates distinct regimes of cellular growth, including a phase of growth arrest resulting from toxicity of the metabolic process. Noise can drive entry of single cells into growth arrest while a fast-growing majority sustains the population. We confirmed these predictions by measuring the growth dynamics of Escherichia coli utilizing lactose as a sole carbon source. The predicted heterogeneous growth emerged at high lactose concentrations, and was associated with cell death and production of antibiotic-tolerant persister cells. These results suggest how metabolic networks may balance costs and benefits, with important implications for drug tolerance.

Publication types

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

MeSH terms

  • Cell Cycle Checkpoints / physiology*
  • Cell Proliferation / physiology
  • Computer Simulation
  • Enzyme Activation
  • Enzymes / metabolism*
  • Escherichia coli / cytology*
  • Escherichia coli / growth & development*
  • Escherichia coli Proteins / metabolism*
  • Metabolic Clearance Rate
  • Models, Biological*
  • Monosaccharide Transport Proteins / metabolism
  • Symporters / metabolism
  • beta-Galactosidase / metabolism


  • Enzymes
  • Escherichia coli Proteins
  • LacY protein, E coli
  • Monosaccharide Transport Proteins
  • Symporters
  • beta-Galactosidase