Contributions of Louis Pasteur & Selman A.Waksman
If you can do, you shall do; If you can’t do, you must do
Louis Pasteur(1822-1895)Chemistry professor in France
Disproved the spontaneous generation theory
Discovered that fermentation of fruits & grains resulting alcohol ,was by microbes
Sorted different microbes giving different taste of wines
Selected a particular strain (yeast) for high quality wine
Louis Pasteur
Pasteur Institute, Paris
Louis Pasteur
Developed a method to remove the undesired microbes from juice without affecting its quality.
Heating the juice at 62.80 C for 30 minutes killed microbes (71.7-15 seconds).
This technique is known as pasteurization, widely used in milk industries
Discovered the parasites (Protozoa) causing pebrine disease of silk worm.
Louis Pasteur
Suggested that disease free caterpillars can eliminate the disease
Isolated the anthrax causing bacilli from bloods of cattle, sheep and human beings
Demonstrated the virulence(ability to cause disease) of bacteria
Demonstrated the principle of immunization & he called the attenuated cultures as vaccines (a term derived from Latin Vacca meaning cow)
Developed vaccine( a killed or attenuated microbe to induce immunity) against rabbits from the brain and spinal cord of rabbit
Germ theory of disease
Bacteria are the cause of disease –reported before Pasteur-but not proved
Verona reported that disease is due to some invisible organisms
Pasteur work on –Pebrine disease of silk worm
Robert Koch work on Anthrax disease of cattle
Pasteur’s demonstration on immunization
During 1880, he isolated the bacterium causing chicken cholera and arranged for a public demonstration.
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 and inoculated with fresh cultures.
The chicken in second groups got sick and died and the first group remained hale and healthy.
Vaccine for chicken cholera
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
Development of rabies vaccine
Rabies (hydrophobia),a disease transmitted to people by bites of dogs, Cats and other animals
A boy Joseph Meister was bitten by a mad wolf He produced this disease in rabbits by inoculating the
saliva from mad dogs
He removed the brain and spinal cord from the infected rabbits, dried, pulverized and mixed with glycerin
Injecting this mixture into dogs protected them against rabies
Joseph Meister was injected with same mix and he was saved after several weeks
Rabies vaccine
Selman A.Waksman
American microbiologist
Isolated of Thiobacillus thiooxidans (Waksman and Joffe, 1922) as his most important scientific discovery before the antibiotics
1927 - Principles of soil Microbiology
In 1939 Waksman and his colleagues undertook a systematic effort to identify soil organisms producing soluble substances that might be useful in the control of infectious diseases, what are now known as antibiotics
Within a decade ten antibiotics were isolated and characterized.
Three of them with important clinical applications actinomycin in 1940, streptomycin in 1944, and neomycin in 1949.
Eighteen antibiotics were discovered under his general direction.
BYR.ABARNABTH-12-001
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