Illustration of how penicillin is made;

How did they make penicillin?

For many years, scientists knew that certain molds killed some bacteria. However, researchers needed to understand how to harness this antibacterial microbe and to manufacture enough of the substance before they could make a useful medicine.

1. Penicillium mold naturally produces the antibiotic penicillin.

2. Scientists learned to grow Penicillium mold in deep fermentation tanks by adding a kind of sugar and other ingredients. This process increased the growth of Penicillium.

3. Then, scientists separated the penicillin product from the mold.

4. Finally, penicillin is purified for use as an antibiotic medicine.