Alexander Fleming (6th August 1881 - 11th March 1955) was a Scottish biologist and pharmacologist. Fleming published many articles on bacteriology, immunology and chemotherapy. His best-known achievements are the discovery of the enzyme lysozyme in 1923 and the antibiotic substance penicillin from the fungus Penicillium notatum in 1928, for which he shared the Nobel Prize in Physiology or Medicine in 1945 with Howard Walter Florey and Ernst Boris Chain. Fleming's discovery and isolation of penicillin in September 1928 marks the start of modern antibiotics. In 1955, Fleming died at his home in London of a heart attack. He was cremated and his ashes interred in St Paul's Cathedral a week later. Fleming was knighted in 1944. Fleming received the Nobel Prize in Medicine in 1945.