Related Experiment Video
Updated: Jul 14, 2026

Non-Invasive Model of Neuropathogenic Escherichia coli Infection in the Neonatal Rat
Published on: October 29, 2014
Modelling the combined temperature and salt (NaCl) limits for growth of a pathogenic Escherichia coli strain using
M A Salter1, D A Ratkowsky, T Ross
1School of Agricultural Science, University of Tasmania, Hobart, Australia.
Abstract:
A broth-based method is used to determine if exponential phase Escherichia coli R31, an STEC, is able to grow within 50 days under various combinations of sub-optimal temperatures and salt concentrations. From these data, the growth limits for combinations of temperature (7.7-37.0 degrees C) and water activity (0.943-0.987; NaCl as humectant) are defined and modelled using a nonlinear logistic regression model. That form of model is able to predict the combinations of salt concentration/water activity and temperature that will prevent the growth of E. coli R31 with selected levels of confidence. The model fitted the data with an approximate concordance rate of 97.3%. The minimum water activity that permitted growth occurred in the range 25-30 degrees C, the temperature range which optimises cell yield. At temperatures below this range the minimum water activity which allowed growth increased with decreasing temperature.
Related Concept Videos
Bacterial Growth Curve
Physical Methods for Controlling Microbial Growth: Temperature
Stringent Response in E. coli
Exponential Equations for Modeling Growth
Derivatives: Problem Solving
Modeling with Differential Equations

