Alexander Fleming shared a Nobel Prize with Florey and Chain in 1945 for the isolation of the antibiotic substance penicillin from the fungus Penicillium notatum in 1928.

It was a discovery that would change the course of history. The active ingredient in that mold, which Fleming named penicillin, turned out to be an infection-fighting agent of enormous potency. When it was finally recognized for what it was — the most efficacious life-saving drug in the world — penicillin would alter forever the treatment of bacterial infections.