The Life Of LOUIS PASTEUR Essays - Food Preservation, Food Science

The Life Of LOUIS PASTEUR Essays - Food Preservation, Food Science The Life of LOUIS PASTEUR Louis Pasteur was born on December 27, 1822, in D?le, a small town in France. He grew in a humble family and his father was a tanner. He graduated in 1840 from the College of Arts at Besancon and entered the prestigious Ecole Namale Supervieure, Paris, to work for his doctorate degree. He chose for his studies the then obscure science of crystallography, which was to have a great influence on his career. Pasteur entered the scientific world as a professor of physics at the Lycee of Tournon and started his research on the optical properties of crystals of tartaric acid salts. He found the two forms of this acid which could rotate the plane of polarization of light, one to the right and the other to the left. This was his first important discovery in crystallography, the phenomenon of optical isomers. Paradoxically it incited him to abandon the field. But it won the acclaim of the French Academy and Britain's Royal Society. Thus Pasteur became famous at the age of 26. Pasteur soon began researching the complexities of bacteriology. The prevalent theory of life at the time was spontaneous generation which states that certain forms of life such as flies, worms, and mice can develop from non-living matter such as mud and decaying fish. Pasteur disproved this theory with a simple experiment. He showed that microorganisms would grow in sterilized broth only if the broth was first exposed to air containing spores, or reproductive cells. His findings led to the development of the cell theory of the origin of living matter which states that all life originates from preexisting living material. In 1849, Pasteur became professor of chemistry at the University of Strasbourg, where he began studying fermentation, a type of chemical breakdown of substances by microbes. He served the rest of his career as Dean of Sciences at the University of Lille. Soon after his arrival at Lille, Pasteur was asked to solve the problems of the local industries, vinegar and silk manufacture. A producer of vinegar from beet juice wanted to know why the product was sometimes spoilt. On examining the juice microscopically, Pasteur observed that the contaminant, amyl alcohol, was optically active. This gave clear evidence that it was produced by a living organism. Pasteur then proposed a biological interpretation of the process of fermentation. He demonstrated that when no contamination by living contagion took place, the process of fermentation or putrefaction did not take place. Thus the celebrated techniques of Pasteurization, came into being, it could not only preserve wine and milk but drastically cut inflation in the surgeon's operating table. Today pasteurization follows closely the early techniques of Louis Pasteur. In the case of milk pasteurization, the milk is heated to 161?F for 15 seconds followed by a rapid cooling to 50?F or lower. This process removes any unwanted bacteria, but also kills any beneficial bac! teria and reduces some of the nutritive property of milk. The Franco-Prussian War opened an avenue to press his microbial theory of infection, he got the grudging agreement of the military medical corps to sterilize instruments and steam bandages. As a result, thousands of lives were saved. In 1873, Pasteur was elected to the French Academy of Medicine, a spectacular achievement for a person without a medical degree. Pasteur was now ready to move from the simpler forms of life in the microbial world to the diseases of the higher animals. The opportunity came through a devastating outbreak of anthrax, a killer plague of sheep in 1876. Pasteur tried to produce pure cultures, his objective was to fight the disease and not just to describe it. Pasteur had accidentally forgotten in a corner of the laboratory a culture of fowl cholera and noticed that it had lost some of its virulence. Then he vaccinated some chicken which resisted the disease. The same technique, after improvement, was applied against bacillus anthracis: sheep inoculated with the vaccine survived and the non-vaccinated ones died. A scourge that had crippling economic effects was brought under control. Simultaneously, the principle of immunization or the protection of the body through vaccines was discovered. In 1865, the silk industry of France faced an economic ruin by an epidemic among silkworms.