A national platform for budding microbiologists

Louis Pasteur was born on 27 December 1822 in Dole, in the Jura region of France, and trained as a chemist. His early research on the asymmetry of tartaric-acid crystals founded the science of molecular chirality — but it was his turn to the living world of microbes that reshaped medicine.

Studying fermentation, Pasteur showed that living micro-organisms, not spontaneous chemistry, turned sugar to alcohol and spoiled wine, beer and milk. His elegant swan-neck-flask experiments disproved the doctrine of spontaneous generation and gave the germ theory of disease its experimental footing. To protect perishable liquids he devised gentle heating — the process the world now calls pasteurization.

Extending Edward Jenner’s idea of inoculation, Pasteur developed vaccines from weakened (attenuated) microbes — for fowl cholera, then anthrax in a famous 1881 public trial at Pouilly-le-Fort, and in 1885 a rabies vaccine that saved the young Joseph Meister. In 1888 the Institut Pasteur opened in Paris as a centre for research, teaching and treatment. He died on 28 September 1895, honoured as one of the founders of modern microbiology and immunology.

Robert Koch was born on 11 December 1843 in Clausthal, in the Harz mountains of Germany, and worked as a country physician before his laboratory discoveries made him a founder of medical bacteriology. Where Pasteur illuminated how microbes behave, Koch proved which specific microbe caused which specific disease.

Working at first with a home microscope, Koch traced anthrax to the bacterium Bacillus anthracis in 1876 and worked out its spore-forming life cycle. He identified the tubercle bacillus (Mycobacterium tuberculosis) in 1882 and the cholera vibrio in 1883–84. From this work he framed Koch’s postulates — the logical criteria still used to link a micro-organism to a disease.

Koch was also a superb technician: he and his colleagues pioneered pure-culture methods on solid media, bacterial staining and photomicrography — techniques (the agar plate, the Petri dish) that made modern microbiology a repeatable laboratory science. He was awarded the Nobel Prize in Physiology or Medicine in 1905 for his investigations of tuberculosis, and died on 27 May 1910 in Baden-Baden.