Alexander Fleming (1881-1955)
Alexander Fleming
  His work on immunology, bacteriology, and chemotherapy is considered groundbreaking and highly influential. His best-known discoveries are the enzyme 'lysozyme' in the year 1923 and the antibiotic substance penicillin from the mould Penicillium notatum in the year 1928, for which he shared the Nobel Prize in Physiology or Medicine in 1945 with Howard Florey and Ernst Boris Chain.