Gram-positive and Gram-negative Bacteria Share Common Principles to Coordinate Growth and the Cell Cycle at the Single-cell Level

Abstract

Bacillus subtilis and Escherichia coli are evolutionarily divergent model organisms that have elucidated fundamental differences between Gram-positive and Gram-negative bacteria, respectively. Despite their differences in cell cycle control at the molecular level, both organisms follow the same phenomenological principle for cell size homeostasis known as the adder. We thus asked to what extent B. subtilis and E. coli share common physiological principles in coordinating growth and the cell cycle. To answer this question, we measured physiological parameters of B. subtilis under various steady-state growth conditions with and without translation inhibition at both population and single-cell level. These experiments revealed core shared physiological principles between B. subtilis and E. coli. Specifically, we show that both organisms maintain an invariant cell size per replication origin at initiation, with and without growth inhibition, and even during nutrient shifts at the single-cell level. Furthermore, both organisms also inherit the same "hierarchy" of physiological parameters ranked by their coefficient of variation. Based on these findings, we suggest that the basic coordination principles between growth and the cell cycle in bacteria may have been established in the very early stages of evolution.

Application of wheat flour (Triticum aestivum) on spore density and sporulation efficiency of Bacillus megaterium isolated from Litopenaeus vannamei gastrointestinal tract

“…The bacterial growth rate actually began to decline when the culture conditions entered the stationary phase (Hall et al 2013). Furthermore, physiologically, there was an increase in the size of B. subtilis cells in line with the growth rate especially in cell length, while the width was constant (Sauls et al 2019). In this study, the dosage of wheat flour presented an important indicator in influencing the growth rate of vegetative cells.…”

A general quantitative relation linking bacterial cell growth and the cell cycle

“…This led us to directly examine Donachie’s hypothesis on the growth-rate-independent initiation mass 2 , 25 , which is supported by multiple recent reports 3,5,26 and is canonically accepted in numerous modeling studies 3,27 , although challenged in some early studies 7,8,28–30 . Our data (Fig.…”

Beyond the average: An updated framework for understanding the relationship between cell growth, DNA replication, and division in a bacterial system

“…During the multifork regime, division and initiation continue to co-vary with population mass doubling time, however, elongation rate (and thus C period) plateaus [ 1 ] ( Fig 1 ). Because of this imbalance, new rounds of replication are started prior to completion of the previous one providing an explanation for the multiple origins of replication observed by Cooper and Helmstetter and others, [ 1 , 15 , 17 – 22 ] including later studies that assess cell size [ 8 , 12 , 23 – 26 ].…”