Louis Pasteur contribution in microbiology | History of microbiology
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Louis Pasteur is known as
Louis Pasteur is known as the father of microbiology; surprisingly, however, he began his career by studying the shapes of organic crystals.
The term “Microbiology”, as the study of living organisms of microscopic size , was coined by Pasteur.
Contributions:
Fermentation
Pasteurization
Spontaneous Generation
Germ theory of disease
Vaccine development (Fowl Cholera, Anthrax and Rabies)
(1)Fermentation:
In 1854, he started his studies on fermentation.
He found that each type of fermentation is carried out by a living microorganism.
He concluded and was able to prove that living cells, the yeast, were responsible for forming alcohol from sugar .
However, before his discovery, people had a misconception about fermentation that it was generated by a series of chemical reactions in which enzymes are produced.
Upon this breakthrough, Pasteur then set out to find some of the specific microorganisms responsible for normal and abnormal fermentations in such things as wine, beer, and vinegar.
He used his research in fermentation to fight against the diseases of wine in 1865.
(2) Pasteurization:
He demonstrated that, when a different microorganism contaminated the wine, lactic acid was produced, making the wine sour.
He concluded that if these substances were heated to a moderately high temperature (62.8 °C for 30 minutes or 71.7 °C for 15 seconds),this would kill the living microorganisms and thereby sterilize(pasteurize) the substances and prevent them from spoiling. The method is called pasteurization.
(3)Spontaneous Generation:
During Pasteur’s time, there was great controversy over the theory of “spontaneous generation”.
Many people believed that things such as beetles, eels, maggots and microbes arise spontaneously from decomposing matter.
Pasteur conducted a series of clever experiments that destroyed every argument supporting spontaneous generation. It was through these experiments that Pasteur proved that all living organisms could develop only from preexisting living thing.
(4)Germ theory of disease:
Taking the theory of fermentation forward, Pasteur helped save the silk industry in 1865.
He and a minority of other scientists believed that diseases arose from the activities of microorganisms—germ theory.
Opponents believed that diseases, particularly major killer diseases, arose in the first instance from a weakness or imbalance in the internal state and quality of the afflicted individual
However, Pasteur proved that microbes were attacking healthy silkworm eggs, causing an unknown disease and that the disease would be eliminated if the microbes were eliminated.
(5)Vaccine Development:
Vaccine for chicken cholera (Attenuated vaccine):
He isolated the bacterium causing chicken cholera. Inoculated healthy chicks with his pure cultures. The chickens failed to get sick and die.
He found that the cultures he used was several weeks old.
Some weeks later he repeated the experiments. He used two groups of chickens – first group which are previously inoculated with old cultures and survived and second group which were not previously inoculated.
Both groups were inoculated with fresh cultures.
The chicken in second groups got sick and died and the first group remained healthy.
He found that the bacteria could loose their ability to produce disease i.e., virulence. But this attenuated bacteria still retained their capacity for stimulating the host to produce substances i.e., antibodies, that protect against subsequent exposure to virulent organisms.
Vaccine for Anthrax:
Anthrax is an infectious disease that affects cattle, sheep, and other livestock that can be transmitted to man.
During this time, anthrax was responsible for killing large populations of sheep in France, and this was detrimental to the economy.
Pasteur supposed that if it were possible to give an animal a mild attack (live but attenuated), this might be sufficient to prevent the animal from getting the disease later on.
Pasteur’s hypothesis was correct. He eventually succeeded in producing a mild, weakened, harmless culture of anthrax bacteria. He then took this culture and vaccinated hundreds of livestock, and they were then immune to the disease.
Vaccine for Rabies:
Rabies (hydrophobia) is a highly contagious, infectious disease that attacks the central nervous system.
Many people have the misconception that those who have rabies act like a wild dog, barking and howling. Rabies enters the body through the bite of an infected animal or infected saliva.
On July 6 ,1885, Pasteur tested his new rabies vaccine on man for the first time.
Joseph Meister was a young man who had been bitten by a rabid dog.
Urged to treat him with his new method, Pasteur gave Meister the rabies vaccine and saved his life.
Rabies was the last achievement for the astonishing scientist.
The term “Microbiology”, as the study of living organisms of microscopic size , was coined by Pasteur.
Contributions:
Fermentation
Pasteurization
Spontaneous Generation
Germ theory of disease
Vaccine development (Fowl Cholera, Anthrax and Rabies)
(1)Fermentation:
In 1854, he started his studies on fermentation.
He found that each type of fermentation is carried out by a living microorganism.
He concluded and was able to prove that living cells, the yeast, were responsible for forming alcohol from sugar .
However, before his discovery, people had a misconception about fermentation that it was generated by a series of chemical reactions in which enzymes are produced.
Upon this breakthrough, Pasteur then set out to find some of the specific microorganisms responsible for normal and abnormal fermentations in such things as wine, beer, and vinegar.
He used his research in fermentation to fight against the diseases of wine in 1865.
(2) Pasteurization:
He demonstrated that, when a different microorganism contaminated the wine, lactic acid was produced, making the wine sour.
He concluded that if these substances were heated to a moderately high temperature (62.8 °C for 30 minutes or 71.7 °C for 15 seconds),this would kill the living microorganisms and thereby sterilize(pasteurize) the substances and prevent them from spoiling. The method is called pasteurization.
(3)Spontaneous Generation:
During Pasteur’s time, there was great controversy over the theory of “spontaneous generation”.
Many people believed that things such as beetles, eels, maggots and microbes arise spontaneously from decomposing matter.
Pasteur conducted a series of clever experiments that destroyed every argument supporting spontaneous generation. It was through these experiments that Pasteur proved that all living organisms could develop only from preexisting living thing.
(4)Germ theory of disease:
Taking the theory of fermentation forward, Pasteur helped save the silk industry in 1865.
He and a minority of other scientists believed that diseases arose from the activities of microorganisms—germ theory.
Opponents believed that diseases, particularly major killer diseases, arose in the first instance from a weakness or imbalance in the internal state and quality of the afflicted individual
However, Pasteur proved that microbes were attacking healthy silkworm eggs, causing an unknown disease and that the disease would be eliminated if the microbes were eliminated.
(5)Vaccine Development:
Vaccine for chicken cholera (Attenuated vaccine):
He isolated the bacterium causing chicken cholera. Inoculated healthy chicks with his pure cultures. The chickens failed to get sick and die.
He found that the cultures he used was several weeks old.
Some weeks later he repeated the experiments. He used two groups of chickens – first group which are previously inoculated with old cultures and survived and second group which were not previously inoculated.
Both groups were inoculated with fresh cultures.
The chicken in second groups got sick and died and the first group remained healthy.
He found that the bacteria could loose their ability to produce disease i.e., virulence. But this attenuated bacteria still retained their capacity for stimulating the host to produce substances i.e., antibodies, that protect against subsequent exposure to virulent organisms.
Vaccine for Anthrax:
Anthrax is an infectious disease that affects cattle, sheep, and other livestock that can be transmitted to man.
During this time, anthrax was responsible for killing large populations of sheep in France, and this was detrimental to the economy.
Pasteur supposed that if it were possible to give an animal a mild attack (live but attenuated), this might be sufficient to prevent the animal from getting the disease later on.
Pasteur’s hypothesis was correct. He eventually succeeded in producing a mild, weakened, harmless culture of anthrax bacteria. He then took this culture and vaccinated hundreds of livestock, and they were then immune to the disease.
Vaccine for Rabies:
Rabies (hydrophobia) is a highly contagious, infectious disease that attacks the central nervous system.
Many people have the misconception that those who have rabies act like a wild dog, barking and howling. Rabies enters the body through the bite of an infected animal or infected saliva.
On July 6 ,1885, Pasteur tested his new rabies vaccine on man for the first time.
Joseph Meister was a young man who had been bitten by a rabid dog.
Urged to treat him with his new method, Pasteur gave Meister the rabies vaccine and saved his life.
Rabies was the last achievement for the astonishing scientist.
4 سال پیش
در تاریخ 1399/02/03 منتشر شده
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