Fleming, Alexander

Scottish bacteriologist who was awarded a Nobel Prize for Physiology or Medicine in 1945 for his discovery of the bactericidal effect of penicillin in 1928. In 1922 he had discovered lysozyme, an antibacterial enzyme present in saliva, nasal secretions, and tears. While studying this, he found an unusual mould growing on a culture dish, which he isolated and grew into a pure culture. This led to his discovery of penicillin, which came into use in 1941. He shared the award with Howard W Florey and Ernst B Chain, whose research had brought widespread realization of the value of penicillin with its isolation and its development as an antibiotic drug.