Alexander Fleming
Alexander Fleming, born 6th August 1881 was a doctor and medical researcher who discovered the antibiotic penicillin. In 1928 when conducting research on influenza he accidentally grew a collection of mould. When he observed the mould it appeared to kill any bacteria that surrounded it, he then isolated the active substance producing the anti-biotic effect, naming it penicillin. http://www.bbc.co.uk/history/historic_figures/fleming_alexander.shtml