1. Louis Pasteur, his investigations and discoveries
South Kazakhstan State Pharmaceutical Academy Department of foreign languages .
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Louis Pasteur, his investigations and discoveries
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2. Plan Introduction Scholar and scientist Germ theory of fermentation
Pasteur effect
Pasteurization
Spontaneous generation
Developing cures for agricultural diseases
Vaccine development
Implications of Pasteur’s work
Conclusion
Internet resource

3. Introduction
"Imagination should give wings to our thoughts, but we always need decisive experimental proof.”
These are the famous words of Louis Pasteur who was one of the greatest scientists of the nineteenth century.
Pasteur is known as the father of microbiology and immunology; surprisingly, however, he began his career by studying the shapes of organic crystals

4. Scholar and scientist
Louis Pasteur was born on Dec. 27, 1822, in D le, France. His father was a tanner. In 1827 the family moved to nearby Arbois, where Louis went to school. He was a hard-working pupil but not an especially brilliant one.
When he was 17 he received a degree of bachelor of letters at the Collage Royal de Besan on. For the next three years he tutored younger students. As part of his studies he investigated the crystallographic, chemical, and optical properties of various forms of tartaric acid. His work laid the foundations for later study of the geometry of chemical bonds. Pasteur's investigations soon brought him recognition and also an appointment as assistant to a professor of chemistry.

5. Pasteur received a doctor of science degree in 1847 and was appointed professor of chemistry at the University of Strasbourg. Here he met Marie Laurent, daughter of the rector of the university. They were married in Pasteur's wife shared his love for science. They had five children; three died in childhood.

6. Germ theory of fermentation
In 1854 Pasteur was appointed professor of chemistry and dean of the science faculty at the University of Lille. While working at Lille, he was asked to help solve problems related to alcohol production at a local distillery, and thus he began a series of studies on alcoholic fermentation. His work on these problems led to his involvement in tackling a variety of other practical and economic problems involving fermentation. His efforts proved successful in unraveling most of these problems, and new theoretical implications emerged from his work. Pasteur investigated a broad range of aspects of fermentation, including the production of compounds such as lactic acid that are responsible for the souring of milk. He also studied butyric acid fermentation.
In 1857 Pasteur left Lille and returned to Paris, having been appointed manager and director of scientific studies at the École Normale Supérieure. That same year he presented experimental evidence for the participation of living organisms in all fermentative processes and showed that a specific organism was associated with each particular fermentation. This evidence gave rise to the germ theory of fermentation.

7. Pasteur effect
The realization that specific organisms were involved in fermentation was further supported by Pasteur’s studies of butyric acid fermentation. These studies led Pasteur to the unexpected discovery that the fermentation process could be arrested by passing air (that is, oxygen) through the fermenting fluid, a process known today as the Pasteur effect. He concluded that this was due to the presence of a life-form that could function only in the absence of oxygen. This led to his introduction of the terms aerobic and anaerobic to designate organisms that live in the presence or absence of oxygen, respectively. He further proposed that the phenomena occurring during putrefaction were due to specific germs that function under anaerobic conditions.

8. Pasteurization
Pasteur readily applied his knowledge of microbes and fermentation to the wine and beer industries in France, effectively saving the industries from collapse due to problems associated with production and with contamination that occurred during export. In 1863, at the request of the emperor of France, Napoleon III, Pasteur studied wine contamination and showed it to be caused by microbes. To prevent contamination, Pasteur used a simple procedure: he heated the wine to 50–60 °C (120–140 °F), a process now known universally as pasteurization. Today pasteurization is seldom used for wines that benefit from aging, since it kills the organisms that contribute to the aging process, but it is applied to many foods and beverages, particularly milk.

9. Following Pasteur’s success with wine, he focused his studies on beer
Following Pasteur’s success with wine, he focused his studies on beer. By developing practical techniques for the control of beer fermentation, he was able to provide a rational methodology for the brewing industry. He also devised a method for the manufacturing of beer that prevented deterioration of the product during long periods of transport on ships.

10. Spontaneous generation
Fermentation and putrefaction were often perceived as being spontaneous phenomena, a perception stemming from the ancient belief that life could generate spontaneously. During the 18th century the debate was pursued by the English naturalist and Roman Catholic divine John Turberville Needham and the French naturalist Georges-Louis Leclerc, count de Buffon. While both supported the idea of spontaneous generation, Italian abbot and physiologist Lazzaro Spallanzani maintained that life could never spontaneously generate from dead matter. In 1859, the year English naturalist Charles Darwin published his On the Origin of Species, Pasteur decided to settle this dispute. He was convinced that his germ theory could not be firmly substantiated as long as belief in spontaneous generation persisted. Pasteur attacked the problem by using a simple experimental procedure. He showed that beef broth could be sterilized by boiling it in a “swan-neck” flask, which has a long bending neck that traps dust particles and other contaminants before they reach the body of the flask. However, if the broth was boiled and the neck of the flask was broken off following boiling, the broth, being reexposed to air, eventually became cloudy, indicating microbial contamination. These experiments proved that there was no spontaneous generation, since the boiled broth, if never reexposed to air, remained sterile. This not only settled the philosophical problem of the origin of life at the time but also placed on solid ground the new science of bacteriology, which relied on proven techniques of sterilization and aseptic manipulation.

12. Developing cures for agricultural diseases
In 1865 Pasteur was asked to help the French silk industry, which was near ruin as a result of a mysterious disease that attacked the silkworms. After intensive research, he discovered that two diseases were involved, both caused by bacteria on the mulberry leaves that provided food for the worms. The diseases were transmitted through the eggs to the next generation of worms. Pasteur showed the silkworm breeders how to identify healthy eggs under the microscope, how to destroy diseased eggs and worms, and how to prevent formation of disease bacteria on the mulberry leaves.

13. Vaccine development
Pasteur’s first important discovery in the study of vaccination came in 1879 and concerned a disease called chicken cholera. (Today the bacteria that cause the disease are classified in the genus Pasteurella.) Pasteur said, “Chance only favours the prepared mind,” and it was chance observation through which he discovered that cultures of chicken cholera lost their pathogenicity and retained “attenuated” pathogenic characteristics over the course of many generations. He inoculated chickens with the attenuated form and demonstrated that the chickens were resistant to the fully virulent strain. From then on, Pasteur directed all his experimental work toward the problem of immunization and applied this principle to many other diseases.

14. In 1877 Pasteur began to seek a cure for anthrax, a disease that killed cattle, sheep, and other farm animals. He drew on research he was conducting on another animal disease, chicken cholera. When he inoculated healthy chickens with weakened cultures of the cholera microbes, the chickens suffered only a mild sickness and were thereafter immune to the disease. Pasteur successfully applied this technique of immunization to the prevention of anthrax.
Many scientists challenged Pasteur's anthrax prevention claims, and Pasteur agreed to a dramatic test. Forty-eight sheep and a few cows and goats were gathered in a pasture near the town of Melun. Half the animals were first immunized with cultures of weakened anthrax microbes; then all were injected with strong cultures.
Within a few days, the untreated animals were dead; but the immunized animals showed no effect of the disease. The test verified Pasteur's results beyond all doubt. Later he proposed that all inoculation cultures be called vaccines and the inoculating technique, vaccination .

15. Treatment for rabies
Human beings contract rabies when they are bitten by a dog or another animal that is suffering from the disease. Rabies slowly destroys the central nervous system by attacking the spinal cord.
Pasteur reasoned that it might be possible to immunize people after they had been bitten but before destruction of the spinal cord began. He took spinal cord tissues of animals that had died of rabies and dried them for varying periods of time. He then made inoculations of the tissues and injected them into another stricken animal. The first inoculation was from the driest, weakest culture, and each successive inoculation was stronger. After repeated failures, he finally succeeded in halting the development of rabies in an infected dog. The treatment required 14 inoculations.
Pasteur hesitated to try the remedy on humans. The decision was forced on him in 1885 when the mother of 9-year-old Joseph Meister begged Pasteur to save her son. The boy had been bitten 14 times by a rabid dog. Pasteur treated the child. The wounds healed and no trace of rabies appeared. Thus Joseph became the first person saved by Pasteur's treatment. Вакцина была настолько успешной, что принесла непосредственную славу и известность Пастера. Сотни других жертв укуса по всему миру были впоследствии спасены Пастера вакцин, и эпоха профилактической медицине начался. Международная кампания по сбору средств была начата строить в Институте Пастера в Париже, открытие которого состоялось 14 ноября 1888.

16. Implications of Pasteur’s work
The theoretical implications and practical importance of Pasteur’s work were immense. Pasteur once said, “There are no such things as pure and applied science; there are only science and the application of science.” Thus, once he established the theoretical basis of a given process, he investigated ways to further develop industrial applications.
At 45 Pasteur was struck by paralysis. For a time recovery was uncertain, and he was confined to bed for months. The attack left its mark; for the rest of his life, one foot dragged a little as he walked.
After Pasteur’s 70th birthday, which was acknowledged by a large but solemn celebration at the Sorbonne that was attended by several prominent scientists, including British surgeon Joseph Lister, Pasteur’s health continued to deteriorate. His paralysis worsened, and he died on September 28, He was buried in the cathedral of Notre-Dame de Paris, but his remains were transferred to a Neo-Byzantine crypt at the Pasteur Institute in 1896.
During Pasteur’s career, he touched on many problems, but a simple description of his achievements does not do justice to the intensity and fullness of his life. He never accepted defeat, and he always tried to convince skeptics, though his impatience and intolerance were notorious when he believed that truth was on his side. Throughout his life he was an immensely effective observer and readily integrated relevant observations into conceptual schemes.

17. Conclusion
The French chemist Louis Pasteur devoted his life to solving practical problems of industry, agriculture, and medicine. His discoveries have saved countless lives and created new wealth for the world. Among his discoveries are the pasteurization process and ways of preventing silkworm diseases, anthrax, chicken cholera, and rabies. He pioneered the study of molecular asymmetry; discovered that microorganisms cause fermentation and disease; originated the process of pasteurization; saved the beer, wine, and silk industries in France; and developed vaccines against anthrax and rabies.
Pasteur’s academic positions were numerous, and his scientific accomplishments earned him France’s highest decoration, the Legion of Honour, as well as election to the Académie des Sciences and many other distinctions. Today there are some 30 institutes and an impressive number of hospitals, schools, buildings, and streets that bear his name—a set of honours bestowed on few scientists.

18. Internet resource