Bacterial strategies in prolonged stationary phase: Tradeoff between cell growth, maintenance, and recycling

Abstract

In continuous starvation, bacteria will enter an extended stationary phase after the death phase. Growth-advantaged genetic mutations gradually emerge in the long-term stationary phase. The different competition patterns between younger and aged cultures, and the constant density and heterogeneity of living cells in very-aged cultures indicate the complexity of population dynamics under prolonged starvation. Based on resource conservation and protein allocation, here we constructed a simple growth-death-recycling model to describe the population dynamics of one or two bacterial strains during long-term starvation. Through analytical derivation or numerical simulation, we produced the survival-extinction phase diagram of one strain at steady state, and that of two strains at steady state, in a limited detection time, or consuming different nutrients. By relating allocated proteomic fractions to growth, death, and recycling rates, we showed the effects of proteome allocation on the phase diagrams. The constraints and optimization of protein allocation lead to the tradeoff between processes for cell growth, maintenance (repair), and nutrient recycling. The results reveal multiple strategies of bacterial survival and coexistence during long-term starvation.