Pasteur There Is Perhaps No

Pasteur

There is perhaps no other individual whose influence is experienced worldwide every day. When one considers that milk and wine can be used and stored for days without fear of spoilage, the word pasteurization comes to mind. This is the process of removing bacteria from the beverage (one way would be by heating and rapid cooling) such that it prevents fermentation. This process was identified and perfected for daily use by one Louis Pasteur. In the pantheon of the 100 most influential people ever, this French chemist and microbiologist stands 11th. (Hart, 1992)

Louis Pasteur was born in Dole in France on December 27, 1822. His school work was not spectacular but he showed an (abbreviated) interest in art (and was a promising artist) and chemistry. Though Pasteur is famous for a slew of inventions and discoveries (described later in this essay) that health specialists take for granted today, few know that he started his scientific career as a chemist. If the biography of Pasteur's life examined in briefly, his achievements seem eclectic. But there is a logical progression of scientific work that allowed him to make the assumptions and connections that are only obvious to the truly great and yet seem obvious in hindsight to the rest of us. This essay will highlight Pasteur's accomplishments and his contribution to chemistry, biochemistry and health sciences through these connections. (Debre & Forster, 1998)

Few know that Pasteur's scientific career began as a crystallographer. This science purports to distill every element and compound to its three dimensional shape and arrangement in its solid form. While studying tartarate crystals that can be found in the sediments of wine, Pasteur discovered that similar looking and behaving crystals were essentially different: they rotated plane polarized light in different directions. Naturally created products were more specific in their behavior than the same product manufactured in laboratories. This gave rise to the notion of stereochemistry and chirality (a carbon atom in an organic molecule that is attached to different atoms and groups). (Morris & Abel, 2002) Here is an example of how chirality is critical. D-Glucose containing certain chiral carbon atoms is responsible for metabolic activities in the body. Artificially manufactured L-Glucose though physically similar if introduced in the body, not only does not perform the function of its D-alternate, but has a debilitating effect on the body.

Pasteur discovered that the tartarate in wine that was contaminated with mould showed different chirality. He deduced that some factor in wine induced chemical changes in it. He showed first that yeast was responsible for fermentation of sugar into alcohol and that this yeast resided in the skin of grapes. He did this by showing that grape juice extracted from under the skin under sterile conditions did not produce wine neither did grapes whose skin had been protected from outside influences. He realized that certain bacteria were responsible for the spoilage of wine (creating of acetic acid vinegar) or the spoilage of vinegar through the creation of lactic acid. Similar effects were observed in milk. By heating the wine and the milk, thereby killing the harmful bacteria, Pasteur could ensure the quality of almost all beverages.

Pasteur showed that fermentation and spoilage was due to outside influences. This helped support the notion of germ theory that had been advanced by other scientists. Germ theory postulated that bacteria and other harmful influences resulted in the disease. Pasteur showed that only broths that were exposed to air could result in fermentation and spoilage. The process of Pasteurization proved this.

This had consequences that went beyond health. Pasteurs work was one of the earliest that supported evolution and dispel the ideas of spontaneous generation, e.g., maggots in rotting matter.

Pasteur believed that germs, just as those that caused fermentation, could also be causing disease. With the support of other scientists and collaborators, he was able to isolate several disease causing bacteria, cholera (with Robert Koch) and small pox (work originally done by Edward Jenner), among several others. While working with cholera in chicken, Pasteur helped set the foundation for the idea of vaccinations; this had been proposed by others earlier. That a mild form of the virus or bacteria induces the creation of antibodies in the host. When infected by a virulent form of the virus or bacteria, the antibodies created in the system can destroy the infecting agents thereby protecting the host. Pasteur's work influenced the creation of vaccinations.

After successfully using it in the cure of cholera, small pox and several other diseases, Pasteur used this idea in identifying a cure for rabies. After several attempts at isolating the rabies virus, Pasteur discovered (from how the disease manifested) that the virus targeted the neurological system including the spinal chord. He injected hosts with the crushed spinal matter of rabbits which he used to incubate the virus extracted from the neural systems of dogs. Pasteur was also known for taking risks. He injected a little boy who had suffered a dog bite and was showing the early signs of the fatal disease. The boy survived. Since Pasteur had no medical license to practice, he almost set himself up for jail time.

Though there is some controversy as to the exact contribution of Louis Pasteur in the isolation of the anthrax virus and the development of a vaccine that salvaged the sheep industry, there is no doubt that he was a major player in this.

Louis Pasteur, pursing the idea the causative agents of disease came from without and not within realized that medical practitioners might be carriers and spreaders of germs. He became a strong advocate of sterile conditions, especially during surgery. He believed that all instruments had to be clean and heated to more than a thousand degrees before use. Along with Joseph Lister, another advocate of clean conditions, several thousand lives with might have been lost despite successful surgery (due to unhygienic conditions) were saved.