Bacterial cell size modulation along the growth curve across nutrient conditions.

Under stable growth conditions, bacteria maintain cell size homeostasis through coordinated elongation and division. However, fluctuations in nutrient availability result in dynamic regulation of the target cell size. Using microscopy imaging and mathematical modelling, we examine how bacterial cell volume changes over the growth curve in response to nutrient conditions.

A Generalized mechanism for Cell Size Homeostasis: Implications for Stochastic Dynamics of Clonal Proliferation.

Measurements of cell size dynamics have revealed phenomenological principles by which individual cells control their size across diverse organisms. One of the emerging paradigms of cell size homeostasis is the , where the cell cycle duration is established such that the cell size increase from birth to division is independent of the newborn cell size. We provide a mechanistic formulation of the considering that cell size follows any .

Stochastic Gene Expression in Proliferating Cells: Differing Noise Intensity in Single-Cell and Population Perspectives.

Random fluctuations (noise) in gene expression can be studied from two complementary perspectives: following expression in a single cell over time or comparing expression between cells in a proliferating population at a given time. Here, we systematically investigated scenarios where both perspectives lead to different levels of noise in a given gene product. We first consider a stable protein, whose concentration is diluted by cellular growth, and the protein inhibits growth at high concentrations, establishing a positive feedback loop.

Mechanisms of cell size regulation in slow-growing Escherichia coli cells: discriminating models beyond the adder.

Under ideal conditions, Escherichia coli cells divide after adding a fixed cell size, a strategy known as the adder. This concept applies to various microbes and is often explained as the division that occurs after a certain number of stages, associated with the accumulation of precursor proteins at a rate proportional to cell size. However, under poor media conditions, E.

Coupling Cell Size Regulation and Proliferation Dynamics of Reveals Cell Division Based on Surface Area.

Single cells actively coordinate growth and division to regulate their size, yet how this size homeostasis at the single-cell level propagates over multiple generations to impact clonal expansion remains fundamentally unexplored. Classical models for cell proliferation (where the duration of the cell cycle is an independent variable) predict that the stochastic variation in colony size will increase monotonically over time. In stark contrast, implementing size control according to strategy (where on average a fixed size added from cell birth to division) leads to colony size variations that eventually decay to zero.

Mechanisms of Cell Size Regulation in Slow-Growing Cells: Discriminating Models Beyond the Adder.

Under ideal conditions, cells divide after adding a fixed cell size, a strategy known as the . This concept applies to various microbes and is often explained as the division that occurs after a certain number of stages, associated with the accumulation of precursor proteins at a rate proportional to cell size. However, under poor media conditions, cells exhibit a different size regulation.

Continuous rate modeling of bacterial stochastic size dynamics.

Bacterial division is an inherently stochastic process with effects on fluctuations of protein concentration and phenotype variability. Current modeling tools for the stochastic short-term cell-size dynamics are scarce and mainly phenomenological. Here we present a general theoretical approach based on the Chapman-Kolmogorov equation incorporating continuous growth and division events as jump processes.

Unification of cell division control strategies through continuous rate models.

Recent experiments support the adder model for E. coli division control. This model posits that bacteria grow, on average, a fixed size before division.

Development of an electrochemical method to determine phenolic monoterpenes in essential oils.

A simple, rapid and non-expensive method is proposed to determine phenolic monoterpenes such as thymol and carvacrol in essential oils of thyme and oregano. The linear sweep voltammetry based on glassy carbon electrodes was the electrochemical technique used. Thymol and carvacrol have one main oxidation peak in non-aqueous media centered at about 1.