Figure 2.

Intergenerational fluctuations and correlations in E. coli cell growth parameters. (A) Scatterplot showing the correlation between k and λ obtained by fitting super-exponential growth model to E. coli cell length versus time data in TSB. The solid black curve represents a fit of Eq. 8 to the data. We remove outliers and the small number of generations in fast growth conditions with $\lambda <0$ from further analysis (see materials and methods). (B) Ensemble-averaged $⟨\lambda ⟩$ versus $⟨k⟩$ across different growth conditions. The black curve is a model prediction for $⟨\lambda ⟩$ as a function of $⟨k⟩$ according to Eq. 9, with $⟨L_0⟩=\left(1.50\mu \mathrm{m}\right)\exp \left(\left(16.19\min \right)⟨k⟩\right)$, $⟨\alpha R_0⟩=\left(0.84\mu m\right)⟨k⟩\exp \left(\left(16.19\min \right)⟨k⟩\right)$, and ${\sigma }_k^2=\left(11.14{\min }^2\right){⟨k⟩}^4+\left(2.67·{10}^{-5}\right){\min }^{-2}$. (C) Marginal probability distributions of $\delta \lambda =\lambda -⟨\lambda ⟩$ across different growth conditions. (D) Marginal probability distributions of $\delta k=k-⟨k⟩$ for each growth condition shown as solid color curves. Dashed curves of the same color depict fits of log-normal distributions. Experimental data presented in (A)–(D) are taken from (4). (E) Representative contour plots of the model predictions for the joint distribution $P\left(k,\lambda \right)$, corresponding to mean growth rates in glucose, MOPS, and TSB media. Darker blue indicates higher probability. To see this figure in color, go online.