Better understand how bacteria multiply

About the episode

Bacteria reproduce by cell growth and division. During each cycle of growth and division, called the cell cycle, the cell must copy all cellular components exactly once. How the cell manages to do this without error is a question that has occupied the scientific field for a long time.

AMOLF researchers have now developed a mathematical model that provides an explanation for this. Because how does a bacterium “know” when it is time to copy its DNA? And what about different growth rates? Recent advances in single-cell microscopy allow researchers to examine individual cells and observe them as they grow and divide.

And it brings new information. First, the bacterium grows by constantly increasing its volume. When the bacterium reaches a certain size, a new cycle of DNA replication begins. To set this in motion, an activator protein must bind to the starting point of the chromosome – with the DNA on it – and then open it up. Replication can then begin.

This activator protein only goes through several other processes before making this bead. What experiments have now shown is that this activator protein can switch between an active and an inactive form during these stages. This keeps the cell cycle stable at different growth rates and eventually gets to that starting point at the right time.

Why do they want to know this in such detail? Because all of this is important information when developing better antibiotics – where you want to stop these bacteria from multiplying – and because there’s a lot of work going on to make an artificial working cell. Because if we can do that – make one that can replicate – we can do a lot more important research with it.

Read more: New reproduction model of E. coli bacteria.