Analysis of a stochastic model for bacterial growth and the lognormality of the cell-size distribution

摘要

This paper theoretically analyzes a phenomenological stochastic model forbacterial growth. This model comprises cell division and the linear growth ofcells, where growth rates and cell cycles are drawn from lognormaldistributions. We find that the cell size is expressed as a sum of independentlognormal variables. We show numerically that the quality of the lognormalapproximation greatly depends on the distributions of the growth rate and cellcycle. Furthermore, we show that actual parameters of the growth rate and cellcycle take values that give a good lognormal approximation; thus, theexperimental cell-size distribution is in good agreement with a lognormaldistribution.