Exponential growth of Escherichia coli B/r during its division cycle is demonstrated by the size distribution in liquid culture

The Collins and Richmond equation was used to analyze the growth of individual bacterial cells. Birth size was derived from the size of deeply constricted cells in the sample. The analysis was applied to normalized and pooled data from electron micrographs of Escherichia coli showing that cellular length, surface, and volume do not grow linearly as reported before. We present evidence that bacteria grow exponentially during the division cycle which is consistent with previous proposals. Our results confirm previous incorporation studies that demonstrate basically exponential growth patterns for cell mass during the division cycle.