Jacques Monod stated that the study of bacterial cell growth is the basic microbiology method (Monod 1949). Each phase of growth defined more than 70 years is of new interest in the light of our current knowledge. Notably, there is an increasing focus on bacterial physiology and the interplay with the environment, especially in infections treatment failures. For example, (i) the duration of the lag time before resuming growth can be heterogeneous between isogenic cells and lead to various responses to antibiotics. Understanding the origin of this heterogeneity and its mechanistic basis is critical to fighting bacterial infections. (ii) The exponential growth phase offers a unique means to reach a meta-stable steady-state in batch cultures that allows for the generation of reproducible physiological states. This physiological steady state also informs us about the fundamental trade-offs in resources allocation at the cellular level that rule bacterial cell proliferation. (iii) Mechanisms controlling entry into and exit from the stationary phase are also of paramount importance, as they encompass the basics of stress resistance until the extreme phenotype of dormancy is observed in clinical contexts and natural environments.

As the field of bacterial cell biology has evolved with recent technological advances, we believe it is time to revisit classical protocols and state-of-the-art methods to explore bacterial proliferation under conditions ever closer to natural habitats and wild microbes. The tools presented in these protocols yield quantitative measurements through the impulse of standard mathematical and statistical procedures, computational models, and artificial intelligence.