French chemist and microbiologist Louis Pasteur was born on December 27 1822 in Dôle. His early academic career was quiet, but within 10 years he had risen to the position of Professor of Chemistry at the University of Strasbourg. He would go on to hold significant positions at the University of Lille and the École Normale Supérieure.

Pasteur developed germ theory, which became central to our understanding of disease. Using experiments and microscopes, Pasteur found that liquids such as beer and milk went off because of the rapid multiplication of very small organisms - germs - in those liquids. He investigated further and found that many of these micro-organisms could be killed by heating the liquid: a preservation method now called ‘pasteurisation’.

Pasteur applied his explanation of decaying liquids to solid matter as well. He showed experimentally that the decay of meat was caused by microbes. The chemist argued that this could explain disease as well as decay, claiming that disease was caused by the multiplication of germs in the body. He investigated his theory using silkworms and went on to develop a new form of vaccination - by chance he discovered that germs which had been weakened by long exposure to the air caused immunity to cholera in chickens. Pasteur’s work made a significant contribution to the development of the first ‘magic bullets’, chemicals developed to attack specific germs.

Pasteur died on September 28 1895. His legacy includes the naming of the process of pasteurisation; the Pasteur Institute, a non-profit foundation dedicated to the study of biology, micro-organisms, diseases and vaccines; a museum; and over 2000 streets named after him in France.

Research interests by date:

1847-1857 crystallography, 1857-1865 fermentation and spontaneous generation, 1865-1870 silkworm diseases; 1871-1876 studies on beer and further debates over fermentation and spontaneous generation; 1877-1895 etiology and prophylaxis of infectious diseases.