Students who have studied biology in high school must be familiar with Pasteur. So today we will introduce the three major problems that Pasteur solved.
Every fermentation is due to the development of a microbe. The French chemist discovered that heating can kill those annoying microbes that make beer bitter. Soon, "pasteurization" was applied to a variety of foods and beverages.
Every infectious disease is the development of a microbe in an organism: Pasteur saved the French silk industry due to the discovery and eradication of a bacterium that attacked silkworm eggs.
Microbacteria of infectious diseases can be reduced in virulence under special cultivation so that they can be transformed from germs into vaccines for disease prevention. Realizing that many diseases are caused by microorganisms, he established the germ theory.
In 1882, Pasteur was elected as an academician of the French Academy. In the same year, he began to study rabies, proved that the pathogen exists in the saliva and nervous system of the animal, and made a live virus vaccine, which successfully helped people obtain immunity to the disease. In accordance with Pasteur's immunization method, medical scientists have created vaccines against several dangerous diseases, successfully eliminating the threat of diseases such as typhoid fever and polio.
When it comes to rabies, people naturally think of Pasteur's popular story. Pasteur did not know that rabies was a viral disease at a time when the bacteriological theory was dominant, but he knew from scientific practice that the repeated passage and drying of infectious substances would reduce their toxicity. He injected the medulla oblongata extract containing the pathogenic rabies multiple times into rabbits, and then injected these attenuated liquids into dogs, after which the dogs were able to resist the infection of normal strength rabies virus.
Later, in 1885, a 9-year-old boy who was bitten by a mad dog was sent to Pasteur for rescue. Pasteur hesitated for a while and injected the child with the above-mentioned extract with very low toxicity, and then gradually inject with a more toxic extract. Pasteur's idea was to make him resistant before the incubation period for rabies had passed. As a result, Pasteur succeeded, and the child was saved.
The French beer and the wine industry was famous in Europe at that time, but beer and wine often turned sour, and the whole barrel of beer turned into a sour mucus that could only be poured out, which made wine merchants very distressed. In 1856, the owner of a winery in Lille asked Pasteur to help find the cause and see if it could prevent the wine from turning sour. Pasteur agreed to study this problem. He observed under the microscope and found that the liquid of the unspoiled old wine contained a kind of spherical yeast cells. When the wine and beer became sour, there were thin sticks in the wine liquid. Lactobacillus, the "bad guy" that thrives in nutrient-rich wines, makes the wine sour.
After figuring out what causes the wine to sour, Pasteur set out to find a solution. He put the closed wine bottle in a wire basket, soaked it in water, and heated it to different temperatures, trying to kill the lactobacillus without boiling the wine. After repeated experiments, he finally found one Simple and effective method: As long as the wine is placed in an environment of fifty or sixty degrees Celsius for half an hour, the lactobacillus in the wine can be killed. This is the famous "Pasteur sterilization method" (also known as the low-temperature sterilization method). This method is still used today, and the sterilized milk sold on the market is sterilized by this method.