Speaker
Description
Microbes adapt their physiology in order to grow in a wide variety of environments. Cellular growth laws quantify the relationship between the levels of essential resources such as ribosomes in a cell and the growth rate under steady-state conditions. However, in nature, the environment inhabited by a cell typically varies with time. A key question is therefore how an individual cell allocates its resources dynamically, as it exits and enters steady-state growth.
Here we present a mathematical model of cell physiology in arbitrary time-dependent conditions. Adopting a coarse-grained approach, we group molecules into broad categories based on their function. We demonstrate how the time-dependent resource allocation fractions may be inferred from plate-reader data for population growth rate and ribosome fraction. We apply our framework to experimental data from budding yeast, a model eukaryotic organism, grown in a range of carbon concentrations and exposed to different levels of translation-inhibiting drug. Our results reveal the principles of transient resource allocation and the potential regulatory mechanisms governing the behaviour of the cell. Our work provides a general quantitative method to elucidate cellular growth beyond steady state.
