Chemist and microbiologist, born in Dôle, E France. He studied at Besançon and Paris universities, and held academic posts at Strasbourg, Lille, and Paris, where in 1867 he became professor of chemistry at the Sorbonne. He established that putrefaction and fermentation were caused by micro-organisms, thus providing an impetus to microbiology and leading to his pasteurization process for milk. In a famous experiment in 1881, he showed that sheep and cows vaccinated with the attenuated bacilli of anthrax received protection against the disease. In 1888 the Institut Pasteur was founded at Paris for the treatment of rabies, and he worked there until his death.
| French microbiologist and chemist | |
| Born |
December 27, 1822 Dole, Jura, France |
| Died |
September 28, 1895 Saint-Cloud, Hauts-de-Seine, Dole |
Louis Pasteur (December 27, 1822 – September 28, 1895) was a French microbiologist and chemist.
Biography
Louis J. Pasteur was born in Dole in the Jura region of France and grew up in the town of Arbois. Throughout his whole life, Louis Pasteur remained an ardent Catholic. (Brittany is a rural region in France renowned for the Catholic piety of its inhabitants.)
Work on chirality and the polarization of light
In Pasteur's early works as a chemist, he resolved a problem concerning the nature of tartaric acid (1849).
Upon examination of the minuscule crystals of tartaric acid, Pasteur noticed that the crystals came in two asymmetric forms that were mirror images of one another. Pasteur correctly deduced the tartaric acid molecule was asymmetric and could exist in two different forms that resemble one another as would left- and right-hand gloves, and that the organic form of the compound consisted purely of the one type. As the first demonstration of chiral molecules, it was quite an achievement, but Pasteur then went on to his more famous work in the field of biology/medicine.
Pasteur's doctoral thesis on crystallography garnered him a position of professor of chemistry at the Faculté (College) of Strasbourg.
Germ theory
Louis Pasteur demonstrated that the fermentation process is caused by the growth of microorganisms, and that the growth of microorganisms in nutrient broths is not due to spontaneous generation.
He exposed boiled broths to air in vessels that contained a filter to prevent all particles from passing through to the growth medium, and even in vessels with no filter at all, with air being admitted via a long tortuous tube that would not allow dust particles to pass. Thus, Pasteur dealt the death blow to the theory of spontaneous generation and supported germ theory.
While Pasteur was not the first to propose germ theory (Girolamo Fracastoro, Agostino Bassi, Friedrich Henle and others had suggested it earlier), he developed it and conducted experiments that clearly indicated its correctness and managed to convince most of Europe it was true.
Pasteur's research also showed that some microorganisms contaminated fermenting beverages.
Beverage contamination led Pasteur to conclude that microorganisms infected animals and humans as well.
In 1865, two parasitic diseases called pébrine and flacherie were killing great numbers of silkworms at Alès. Pasteur worked several years proving it was a microbe attacking silkworm eggs which caused the disease, and that eliminating this microbe within silkworm nurseries would eradicate the disease.
Pasteur also discovered anaerobiosis, whereby some microorganisms can develop and live without air or oxygen.
Immunology and Vaccination
Pasteur's later work on diseases included work on chicken cholera. Upon reusing these healthy chickens, Pasteur discovered that he could not infect them, even with fresh bacteria; His assistant Charles Chamberland (of french origin) had been instructed to inoculate the chickens after Pasteur went on holiday. Chamberland assumed an error had been made, and wanted to discard the apparently faulty culture when Pasteur stopped him. Pasteur guessed the recovered animals now might be immune to the disease, as were the animals at Eure-et-Loir that had recovered from anthrax.
In the 1870s, he applied this immunization method to anthrax, which affected cattle, and aroused interest in combating other diseases.
Pasteur publicly claimed he had made the anthrax vaccine by exposing the bacillus to oxygen. His laboratory notebooks, now in the Bibliotheque Nationale in Paris, in fact show Pasteur used the method of rival Jean-Joseph-Henri Toussaint, a Toulouse veterinary surgeon, to create the anthrax vaccine. Pasteur's oxygen method did eventually produce a vaccine but only after he had been awarded a patent on the production of an anthrax vaccine.
The notion of a weak form of a disease causing immunity to the virulent version was not new; Edward Jenner had also discovered vaccination, using cowpox to give cross-immunity to smallpox (in 1796), and by Pasteur's time this had generally replaced the use of actual smallpox material in inoculation. The difference between smallpox vaccination and cholera and anthrax vaccination was that the weakened form of the latter two disease organisms had been generated artificially, and so a naturally weak form of the disease organism did not need to be found.
This discovery revolutionized work in infectious diseases, and Pasteur gave these artificially weakened diseases the generic name of vaccines, to honour Jenner's discovery. Pasteur produced the first vaccine for rabies by growing the virus in rabbits, and then weakening it by drying the affected nerve tissue.
The rabies vaccine was initially created by Emile Roux, a French doctor and a colleague of Pasteur who had been working with a killed vaccine produced by desiccating the spinal cords of infected rabbits.
This vaccine was first used on 9-year old Joseph Meister, on July 6, 1885, after the boy was badly mauled by a rabid dog. This was done at some personal risk for Pasteur, since he was not a licensed physician and could have faced prosecution for treating the boy. After consulting with colleagues, Pasteur decided to go ahead with the treatment.
Honors and final days
Pasteur won the Leeuwenhoek medal, microbiology's highest honor, in 1895. He was buried in the Cathedral of Notre Dame, but his remains were soon placed in a crypt in the Institut Pasteur, Paris, and will be remembered for his life saving works. A historical review of Pasteur's work Tiner, John Hudson : "Louis Pasteur: Founder of Modern Medicine". Lie of Louis Pasteur (originally Pasteur, Plagiarist, Imposter), 1940 Dr M.R.
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