Inferring fungal growth rates from optical density data
Fig 5
Hyphal growth rate estimated by Logistic-OD-calibration model and inferred true fungal growth from model fit to OD600.
(a) Medians (dot), 95% (thin line) and 80% (thick line) credible intervals of hyphal growth rates (reference rates, green) estimated from logistic models fit to direct data (Logistic-HL and Logistic-NC fit to hyphal length and nuclear count data, respectively) compared to the estimated hyphal growth rate from our Logistic-OD-calibration model fit to all the OD600 data (blue). The 80% and 95% credible intervals ([0.352, 0.371] and [0.348, 0.376] 3.s.f., respectively) of the growth rate inferred using our Logistic-OD-calibration model (blue) overlap with the credible intervals of reference growth rates (green), but the credible intervals of the growth rate of the Logistic-OD model (black) do not. (b) Inferred true fungal growth, f(t), in [N/μl] (log10 scale) from our Logistic-OD-calibration model when modelling fungal growth from OD600 data measured from wells inoculated with 1, 101, 102, 103 [N/μl] (left to right). Solid lines and shades are medians and 95% credible intervals, respectively. (c) Logistic-OD-calibration model fit (posterior predictive distribution, medians shown in solid blue line and 95%, 80%, 60% credible intervals shaded) to measured OD600 (dots) from wells inoculated with 1, 101, 102, 103 [N/μl] (left to right), where the OD600 data was treated as distributed around a linear transform of the true fungal growth, f(t) (shown in (b)). The y-axis is in the log10 scale.