Bacterial Growth: Not So Simple

Summary Bacterial growth is used as a simple example of exponential growth, but a population often grows much faster than the average time-to-division suggests. We examine the effect of randomness in the time-to-division of individual bacteria and the aggregate population growth, revealing intricacies that are often overlooked. Specifically, the average time-to-division of individual bacteria does not by itself determine the aggregate population growth. Exponential population growth occurs in realistic scenarios, but the aggregate growth factor depends in nonobvious ways on the underlying splitting distribution.