Statistical model fitting Escherichia coli survival data during starvation in artificial sea water

The survival of Escherichia coli in artificial sea water was studied using linear and nonlinear regression analysis in order to fit the simplest model. The surviving population was evaluated in a rich medium, and two mathematical models, monophase and diphase linear, were considered. The diphase model gave the best fit, although both models can be adjusted to the results obtained. The criteria applied to decide which model was more statistically significant, were residuals, the residual sum of squares and the coefficient of determination. These models are discussed in the light of present day knowledge on survival.