Louis Pasteur Totally Explained

Everything about Pasteur totally explained

Louis Pasteur (December 27, 1822 – September 28, 1895) was a French chemist and microbiologist best known for his remarkable breakthroughs in the causes and prevention of disease. His experiments supported the germ theory of disease, also reducing mortality from puerperal fever (childbed), and he created the first vaccine for rabies. He was best known to the general public for inventing a method to stop milk and wine from causing sickness - this process came to be called pasteurization. He is regarded as one of the three main founders of microbiology, together with Ferdinand Cohn and Robert Koch. He also made many discoveries in the field of chemistry, most notably the asymmetry of crystals. There he later had his house and laboratory, which is a Pasteur museum today. His father, Jean Pasteur, was a poorly educated tanner where he met and courted Marie Laurent, daughter of the university's rector in 1849. They were married on May 29, 1849 and together they'd five children, only two of whom survived to adulthood. Throughout his life, Louis Pasteur remained an ardent Catholic. A well-known quotation illustrating this is attributed to him: "The more I know, the more nearly is my faith that of the Breton peasant. Could I but know all I'd have the faith of a Breton peasant's wife."

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). A solution of this compound derived from living things (specifically, wine lees) rotated the plane of polarization of light passing through it. The mystery was that tartaric acid derived by chemical synthesis had no such effect, even though its chemical reactions were identical and its elemental composition was the same.but rather to biogenesis (Omne vivum ex ovo). 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 wouldn't allow dust particles to pass. Nothing grew in the broths; therefore, the living organisms that grew in such broths came from outside, as spores on dust, rather than spontaneously generated within the broth. This was one of the last and most important experiments disproving the theory of spontaneous generation. The experiment also supported germ theory.
Pasteur's research also showed that some microorganisms contaminated fermenting beverages. With this established, he invented a process in which liquids such as milk were heated to kill most bacteria and molds already present within them.
Beverage contamination led Pasteur to conclude that microorganisms infected animals and humans as well. He proposed preventing the entry of microorganisms into the human body, leading Joseph Lister to develop antiseptic methods in surgery.

Immunology and vaccination

Pasteur's later work on diseases included work on chicken cholera. During this work, a culture of the responsible bacteria had spoiled and failed to induce the disease in some chickens he was infecting with the disease. Upon reusing these healthy chickens, Pasteur discovered that he couldn't infect them, even with fresh bacteria; the weakened bacteria had caused the chickens to become immune to the disease, even though they'd only caused mild symptoms.
   His assistant Charles Chamberland (of French origin) had been instructed to inoculate the chickens after Pasteur went on holiday. Chamberland failed to do this, but instead went on holiday himself. On his return, the month old cultures made the chickens unwell, but instead of the infection being fatal, as it usually was, the chickens recovered completely. 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 immunisation method to anthrax, which affected cattle, and aroused interest in combating other diseases.
   Pasteur publicly claimed he'd 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. This method used the oxidizing agent potassium dichromate. Pasteur's oxygen method did eventually produce a vaccine but only after he'd 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 wasn't new; this had been known for a long time for smallpox. Inoculation with smallpox was known to result in far less scarring, and greatly reduced mortality, in comparison to the naturally acquired disease. 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 didn't 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. The vaccine had only been tested on eleven dogs before its first human trial.
   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..

Honours and Final Days

Pasteur won the Leeuwenhoek medal, microbiology's highest honor, in 1895.

He was a Grand Croix of the Legion of Honor–one of only 75 in all of France.
He died in 1895, near Paris, from complications of a series of strokes that had started in 1868 He was buried in the Cathedral of Notre Dame, but his remains were reinterred in a crypt in the Institut Pasteur, Paris, where he's remembered for his life-saving work.

Statements

In his triumphal lecture at the Sorbonne in 1864, Pasteur said "Never will the doctrine of spontaneous generation recover from the mortal blow struck by this simple experiment" (referring to his swan-neck flask experiment wherein he proved that fermenting microorganisms wouldn't form in a flask containing fermentable juice until an entry path was created for them).

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