Origin of Exponential Growth in E. coli

Exponential proliferation is a hallmark of bacterial growth. In E. coli and many other rod-shaped bacteria, cell elongation is often approximated by an exponential function, typically attributed to autocatalytic processes. However, this exponential growth model is fundamentally at odds with the standard framework of the central dogma, which links gene expression to protein production. In this study, we critically examine the assumptions underlying these models by integrating theoretical modeling of gene expression, protein production, and the cell cycle with single-cell experiments. We explore conditions under which exponential elongation of E. coli is expected and, more importantly, when it deviates from this behavior.