Sir Alexander Fleming

Facts

Sir Alexander Fleming

Photo from the Nobel Foundation archive.

Sir Alexander Fleming
The Nobel Prize in Physiology or Medicine 1945

Born: 6 August 1881, Lochfield, Scotland

Died: 11 March 1955, London, United Kingdom

Affiliation at the time of the award: London University, London, United Kingdom

Prize motivation: “for the discovery of penicillin and its curative effect in various infectious diseases”

Prize share: 1/3

Work

Among microorganisms, life is a constant battle for survival. Alexander Fleming became interested in this. He used to leave bowls with bacteria cultures standing by his worktable. In 1928 he saw that in addition to bacteria, a mold fungus had begun to grow in a bowl and that the bacteria's growth had been impeded in the vicinity of the mold. He concluded that the mold contained a substance that was effective against bacteria. The substance was given the name penicillin and became the basis for medication to treat bacterial infections.

To cite this section
MLA style: Sir Alexander Fleming – Facts. NobelPrize.org. Nobel Prize Outreach AB 2023. Fri. 29 Sep 2023. <https://www.nobelprize.org/prizes/medicine/1945/fleming/facts/>

Back to top Back To Top Takes users back to the top of the page

Coming up

This year’s Nobel Prize announcements will take place 2–9 October. All announcements will be streamed live here on nobelprize.org.

See the full schedule
Announcement dates

Explore prizes and laureates

Look for popular awards and laureates in different fields, and discover the history of the Nobel Prize.