The figure of this scientist brought us relevant advances in the field of biology.
The possibility that one could get sick from small beings that were not visible to the human eye and that, moreover, were tiny, was not considered. How was it possible for someone to get sick from something so small and seemingly weak?
In addition to this lack of knowledge about the spread of diseases, at the time the idea that there were annoying animals, such as flies and rats, that arose magically and without any being that generated them, was widely shared.
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Brief biography of Louis Pasteur
However, Louis Pasteur managed to refute these ideas, carrying out a very exhaustive investigation that not only allowed him to acquire world fame but also saved thousands of lives with his findings.
Let’s see who this French chemist and bacteriologist was and what contributions he made to the world of science.
early years
Louis Pasteur was born in a French municipality called Dôle on December 27, 1822 . He spent his childhood mostly in the town of Arbois, in Franche-Comté.
Although he is known today for being one of the most important chemists and microbiologists in history, the truth is that the young Louis was not very given to the natural sciences.
During his childhood, he showed pictorial aptitudes, in fact, his first great ambition was to become an art teacher. Chemistry was not his strong point, getting fairly mediocre grades and not showing enough interest, according to his first teachers.
His father, Jean-Joseph Pasteur, who was a tanner, forced the young Louis to study at the Lycée de Besançon, where he obtained a bachelor’s degree in letters (1840) and science (1842).
Professional life
Having completed his baccalaureate studies, he was admitted to the École Normale Supérieure in Paris , where he received poor grades the first year. After a year he returned and it was from then on that he began to show interest in chemistry, thus beginning his most remarkable scientific and professional career.
In 1847 he received his doctorate in physics and chemistry, later becoming a professor of physics at the Lycée de Dijon and then in Strasbourg. It was there that he met his wife, Marie Laurent, with whom he had five children, two of whom reached adulthood.
In 1854 he obtained the position of dean in the faculty of sciences at the University of Lille. From 1857 he would hold the position of director of scientific studies at the École Normale and ten years later he would be in charge of the laboratory of that same institution.
In 1888 the Pasteur Institute was founded, which Louis Pasteur himself would direct until the date of his death. Louis Pasteur died of cardiorespiratory arrest on September 28, 1895 at the age of 72.
scientific work
Although as a child she wanted to be an artist, when she was a little older she showed herself to be a great scientist in the area of chemistry and microbiology , offering the world great discoveries that have contributed to the reduction of diseases and their consequences.
1. Optical isomerism
A year after having received his doctorate in chemistry, at the age of 26, Louis Pasteur was able to solve one of the great mysteries of the time . At that time it was already known that tartaric acid came in two forms, of identical composition but with different physical properties.
The substance is synthesized by living beings, but it can also be produced under laboratory conditions, except that the one produced by living beings was capable of polarizing light while the synthetic one was not.
The young Pasteur looked at both versions of the substance and saw that, under the microscope, synthetic tartaric acid had crystals of two types, which were mirror images of each other.
Thus, the chemical composition of these crystals was the same, but their structure was different. This caused some crystals to polarize light to the right and others to the left.
Observing the tartaric acid produced by living beings, he observed that there was only one type of crystal, the one that made light polarize to the right.
2. Pasteurization
At the time, it was thought that fermentation, with which dairy products and alcoholic beverages are obtained, was a chemical process in which there was no action of any living organism.
However, Pasteur refuted this theory, since he discovered that living beings were involved in the process, specifically two types of yeast, one producing alcohol and the other lactic acid.
After observing this, he developed a method with which he heated the wine up to 44º C for a short time in order to kill those organisms that could spoil the drink.
This process was what would later be called pasteurization , a method by which Pasteur is widely known as well as being what allows guaranteeing the safe consumption of hundreds of food products today.
3. The twilight of spontaneous generation
Before the appearance of Pasteur, it was held that there were some living beings, such as flies, worms or even rats, that were generated suddenly, without the need for a parent to have conceived them.
Although this idea may sound somewhat crazy, at that time experiments were carried out that claimed to have shown that the theory was true, despite the fact that they had not been carried out in the most rigorous way. However, Louis Pasteur was able to refute these ideas.
His experiment consisted of introducing boiled broth into flasks. Some flasks had a filter that prevented the entry of air, while others had no filter, although the neck was very long and curved, making it difficult for air to enter but not preventing it.
After a while, he observed that in none of the flasks, both those with filters and those without, nothing had grown, showing that if something grows in a place it must necessarily come from outside, in the form of spores or contaminated dust.
Thus, Pasteur showed that organisms do not arise spontaneously inside an isolated environment , but had to come from outside. This was what definitively ended the theory of spontaneous generation.
In addition, based on his findings, he formulated the principle ‘omne vivum ex ovum’, which means that every living being comes from a previous living being.
Thanks to this, he laid the foundations for the formulation of the germ theory of diseases, in addition to the cell theory and modern microbiology.
4. Germ theory and vaccination
In 1865 the south of France was experiencing serious economic problems because silk production was declining. The cause of this seemed to be diseases in the silkworms, causing large losses.
After four years of research, Pasteur was able to observe that there were not one but two diseases that affected silkworms. One produced by parasites that attacked the worms in their initial stage, and the other produced by parasites in the leaves on which they fed.
The best option to end the disease was to eliminate the worms and plants that were contaminated, making sure that those that were healthy did not get infected.
Following these discoveries, he delved deeper into the origin of contagious diseases .
The idea that there were diseases that could be spread by large animals and other people was accepted, especially taking into account historical precedents such as the Black Death.
However, the scientific community at the time was reluctant to accept that microorganisms could be the cause of diseases manifested in living beings much larger than themselves.
From here, Pasteur developed the germ theory of contagious diseases, according to which these diseases have their origin in a microscopic living being, which can spread between people and generate chemical processes such as fermentation and decomposition.
This refuted the general idea of the time, which was that all disease was the product of an imbalance in the humors within the body, according to the most classical view of medicine.
Although the theory was not initially popular, it motivated many health professionals to take measures to sterilize surgical components, which increased the survival of patients in the postoperative period.
Based on what was observed about contagious diseases, Pasteur accidentally discovered how to improve resistance to this type of medical condition.
While he was researching the mechanism of transmission of bacteria in chickens, his research team carelessly misplaced the bacteria they wanted to inoculate the birds with. After some time had passed, they decided to see what would happen if the bacterium, which was weakened, was inoculated, seeing that the birds survived despite showing some symptoms.
Although the idea that inoculating a weakened disease could produce immunity to it was reported by Edward Jenner in 1796, inoculating it into cows, it did not seem that the subject had been investigated very thoroughly until Pasteur’s time. In honor of Jenner, Pasteur named this technique vaccination.
Pasteur’s opportunity to test this new technique on humans came in 1885. That year, a boy named Joseph Meister had had the very bad luck of being bitten fourteen times by a dog with rabies.
The child’s fate seemed to be sealed, since at the time the disease had no known cure and was synonymous with death in a matter of days.
Pasteur tried to see what would happen if he inoculated the pathogenic agent of rabies. Despite the legal risks, since Pasteur was not a doctor, he was successful and the child was saved .
Bibliographic references
- Debre , P. and Forster , E. (2000). Louis Pastor. Johns Hopkins University Press.
- Martinez-Baez, M. (1972). Pasteur: Life and work. Mexico: Economic Culture Fund.
- Tiner, J. H. (1990). Louis Pasteur: Founder of Modern Medicine. Mott Media.
- Vallery Radot, R. (1937). Life of Pasteur. flammarion
To the classic question “what do you do?” I always answer “basically I am a psychologist”. In fact, my academic training has revolved around the psychology of development, education and community, a field of study influenced my volunteer activities, as well as my first work experiences in personal services.