It’s a Numbers Game
Learn how bacteria grow.
Parents are usually 20-40 years older than their children.
A typical generation time for hamsters 🐹 can be as short as 6 weeks, for mosquitoes 🦟 10 days.
For E. coli bacteria 🦠, this only takes 20 minutes!
Bacteria multiply by dividing into two identical ‘daughter cells’. This means when you start with 1 bacterial cell and provide all the goodies it needs to grow (sugar, salt, water, some special nutrients like amino acids), after 20 minutes you’ll have 2 bacteria.
After another 20 minutes you’ll have 4 bacteria, after 20 more minutes you’ll have 8 bacteria.
The number of E. coli cells doubles every 20 minutes, which means bacteria can increase in number very quickly… Take a look at the graph and see what this means over longer periods of time!
With time the tiny bacterium that you can’t see without a microscope grows into a lump of bacteria that form a visible spot, a ‘colony’, on an agar plate.
Each such bacterial colony originates from a single individual bacterium. This way you can quite easily count how many bacteria you had at the beginning of your experiment.
Now imagine you started an experiment and plated a single bacterium on an agar plate at 9:00 in the morning.
We already know now that at 10:00 you would have 8 bacteria. But how many would you have at 12:00, at 16:00, at 21:00? 🤔
How many would you have at 6:00 o’clock on the next morning, if the bacteria had sufficient space and nutrients to keep on dividing? ⏰
Try to see if you can answer the following questions correctly.
Click on the flags below to do a little Quiz:
➡️ Grow Your Own Microbes
Take a look at the bacteria that are on your skin and live in your mouth, ears and nose - and that sit on the dirty screen of your mobile phone.