Stochasticity and Homeostasis in Macromolecular Crowding and its Effects on the Rates of Reproduction

Binary fission can be prone to noise and stochasticity, with daughter cells rarely born at identical sizes with each other. Here, we will present our recent results on how the mother's mass and macromolecular load is also not necessarily divided equally between daughter cells. This phenomenon gives rise to a non-genetic form of cell-to-cell variability in the intracellular levels of macromolecular crowding. We will discuss how this form of stochasticity in macromolecular load levels is subject to homeostasis. In this context, individual cells undergo a form growth differentiation with some exhibiting higher mass accumulation rates identical size and mass rates. This form of differentiation not only acts as a homeostatic mechanism against crowding noise, but also has distinct impacts on the reproduction rates of single-bacteria and, as such, the growth-rates of a population. We will conclude with the dedicated quantitative-mass imaging method we developed for this work, as well as the invisible microfluidics we deployed to specifically enhance the precision of our measurements by more than 60%.