Modelling the effects of temperature, water activity, pH and lactic acid concentration on the growth rate of Escherichia coli

Int J Food Microbiol. 2003 Jan 26;82(1):33-43. doi: 10.1016/s0168-1605(02)00252-0.


An extended square root-type model describing Escherichia coli growth rate was developed as a function of temperature (7.63-47.43 degrees C), water activity (0.951-0.999, adjusted with NaCl), pH (4.02-8.28) and lactic acid concentration (0-500 mM). The new model, based on 236 growth rate data, combines and extends previously published square root-type models and incorporates terms for upper and lower limiting temperatures, upper and lower limiting pH, minimum inhibitory concentrations of dissociated and undissociated lactic acid and lower limiting water activity. A term to describe upper limiting water activity was developed but could not be fitted to the E. coli data set because of the difficulty of generating data in the super-optimal water activity range (i.e. >0.998). All data used to generate the model are presented. The model provides an excellent description of the experimental data.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Division / drug effects
  • Escherichia coli / cytology
  • Escherichia coli / drug effects
  • Escherichia coli / growth & development*
  • Escherichia coli / metabolism
  • Hydrogen-Ion Concentration
  • Kinetics
  • Lactic Acid / pharmacology*
  • Models, Biological*
  • Temperature
  • Water / metabolism*


  • Water
  • Lactic Acid