Implications of Aging in Bacteria

Motivated by recent research of aging in E. coli, we explore the effects of aging on bacterial fitness. The disposable soma theory of aging was developed to explain how differences in lifespans and aging rates could be linked to life history trade-offs. Although generally applied for multicellular organisms, it is also useful for exploring life history strategies of single celled organisms such as bacteria. Starting from the Euler-Lotka equation, we propose a mathematical model to explore how a finite lifespan effects fitness of bacteria. We find that that there is surprisingly little loss of fitness when the bacterium has limited opportunities to reproduce. Instead, the fitness gained each time the bacteria reproduces decreases rapidly, and investing resources to survive to reproduce the first few times is likely more advantageous than investing additional resources to try to maintain cell integrity longer.