/kloc-in the 0/9th century, due to the needs of capitalist development and production, scientific and technological research in physics, chemistry and biology flourished, and bacteriology also made rapid progress. /kloc-in the second half of the 0/9th century, some important issues, such as the origin of microorganisms, the essence of fermentation, the cause of infectious diseases and immune control, were basically clarified. Therefore, the19th century can be regarded as the basis of microbiology.
Bankrupt microorganisms originated from spontaneous occurrence theory, and the debate between spontaneous occurrence theory and unnatural occurrence theory has a long history. It was not until 1836 that Schoultze (Schulze, F.1815 ~1873) noticed the existence of microorganisms in the air, and designed experiments to prove that the corruption of animal or plant organic solutions was caused by the entry of microorganisms in the air. Later, Wang Shi (Shi Wan, T.18/kloc-0 ~1882) and Schroeder (Schroeder, H.G.F. 18 10) wrote in1850. T. von 1824 ~ 1890), 1860 Hoffman (H.1819 ~1891), etc. On the basis of Schultz's experiments, their designs are constantly improved to prove this property. 186 1 year, Pasteur (L. 1822 ~ 1895) made a famous U-shaped flask experiment, which proved that microorganisms exist widely in the air with irrefutable facts. Only when these microorganisms enter the gravy will the organic matter in the gravy decompose and rot. If the air is isolated or purified, the sterilized gravy will not rot. In this regard, in 1864, Pasteur published a research report at the French scientific conference, which confirmed that microorganisms in gravy did not "naturally occur", thus overthrowing the long-standing theory of spontaneous occurrence.
4 Clarify the essence of fermented fermented vinegar, which has been known for a long time. But what is its essence? Before Pasteur did a lot of work, he was not completely sure.
1837, Wang Shi discovered yeast, and claimed that the formation of alcohol was the result of yeast decomposing sugar in fruit juice. At the same time, however, scholars, led by German chemist Justus von Liebig (J.F. von 1803 ~ 1873), argue that yeast only plays a role in ventilation in juice, emphasizing that the production of alcohol is purely a chemical change.
During the period of 1848, Pasteur made a preliminary study on tartaric acid formed at the bottom of wine vat, and found that microorganisms had a selective effect on the utilization of dextrorotatory and levorotatory tartaric acid. During the period of 1857 ~ 1862, he proved that yeast was the cause of wine and beer fermentation. As for the wild yeast that causes alcohol to ferment into vinegar, it can be killed by heating at 60 ~ 65℃ for 30 minutes. Now the pasteurization of alcohol and milk begins here. Later, he clarified that the corruption of other substances was also caused by the decomposition of some microorganisms, and found that some microorganisms could only proliferate in an oxygen-free environment. These studies of Pasteur made microbiology enter the physiological era from the morphological stage, and he became the founder of bacteriology.
The fermentation principle expounded by Pasteur not only has great significance and economic benefits in the brewing industry, but also has a far-reaching impact on the fields of medicine and health. An example is the antiseptic operation established by British surgeon Liszt (J.1827 ~1912) in 1852.
The establishment of microbial pathogen theory and the discovery of special pathogens in the early stage, the understanding of the pathogens of diseases was very vague, some of which were attributed to filthy gas, and some were attributed to ghosts and gods. 1546 fracas storrow (g.1478 ~1553) thinks that the cause of infectious diseases is a disease bud, and in his book, he explains in detail that the infection of diseases is caused by direct contact, indirect contact with infectious substances or air transmission. 1720, Ma Teng (date of birth and death unknown) expounded the law of tuberculosis transmission. 1762 plenciz (m.a.von1705 ~1786) means that special organisms cause special diseases. 1840, Henle (J. 1809 ~ 1885) elaborated the infectious theory of diseases, pointed out the specificity of pathogens, and proposed that patients were related to infectious substances or infectious substances according to his microbial pathogen theory. Pathogens must be isolated; Three arguments that diseases will occur when pathogens are inoculated into healthy people. Henry's theory was formally confirmed by Koch (R.1843 ~1910) and other studies.
The fact that some bacteria can cause diseases was first confirmed by Koch (1876). 1863 ~ 1868 Fan Dan (Davaine, C.J.1812 ~1882) found that there were rod-shaped bodies in the blood and organs of animals who died of anthrax, and these bodies were also inoculated into healthy animals. Koch cultured it in serum or aqueous humor, which can be propagated from generation to generation. Therefore, he thinks these corpuscles are living bacteria. Moreover, although the experimental animals were inoculated many times, they still died of anthrax with typical symptoms, and there were also special bacilli in blood and organs. This confirms that Bacillus anthracis is the pathogen of anthrax. Therefore, Koch put forward the following assumptions: ① there should be special microorganisms in the body of a certain disease, but not in the healthy body; ② This special microorganism can be isolated and cultured to obtain purebred; ③ Inoculating this pure culture to susceptible animals can cause the same diseases; ④ Pure culture can still be obtained by artificially infecting experimental animals. Koch hypothesis does have important guiding significance in identifying pathogens, but some exceptions should be paid attention to. For example, obviously healthy people can be carriers of bacteria or drugs, some pathogens have not been artificially cultured in vitro so far, and there are also suitable susceptible animals.
Koch's hypothesis, accompanied by his solid culture medium, separation and culture techniques and staining methods, has made a large number of scholars deeply study the pathogens of various infectious diseases. In the last two decades of the19th century, the pathogens of most infectious diseases were identified and successfully isolated and cultured.
6 Progress in Microbiology Techniques and Methods1The rapid development of bacteriology in the 9th century is inseparable from the improvement and creation of its techniques and methods. Among them, the important ones are:
6. 1 Improvement of bacterial culture method ① In 1854, Schleder and Duchy used cotton plugs to prevent airborne bacteria from entering the sterilized culture; ② In 1872, Schleder used potato oblique slices as culture medium, and found colonies with different pigments on its surface, which proved that each colony only contained one type of bacteria; ③ 1873 klebers (e.1834 ~1913), 1877 pasteur, 1878 Liszt, 1879 Nigeria. Gree, C. Feng1817 ~1891), etc. Used to separate and cultivate pure bacteria; ④ Roberds (Roberts, W. 1830 ~ 1899) and Cohen (Cohn, F. 1828 ~ 1898) initiated the heating separation culture method in 1876. ⑤ 1877, Pasteur first sterilized the culture medium at high temperature or in stages (founded by [Tyndall, j. 1893]), killed the original miscellaneous bacteria and spores in it, and then used it for culture, which can avoid the culture results. ⑥ 188 1 year, Koch made a semi-solid nutrient medium from animal gelatin, or coated mixed bacteria on its surface, or mixed the bacteria with gelatin that was still liquid after cooling to a certain temperature for pouring culture, thus dispersing and purifying the bacteria. However, due to the low melting point of gelatin, the culture temperature should not exceed 20℃; Some bacteria grow slowly at 20℃; Some can decompose gelatin and remix dispersed bacteria, which is their shortcoming; ⑦ 1882 and Koch's student Hess (W.1846 ~191) were inspired by his wife to change agar to gelatin. Agar is liquid near 100℃, and solidified when it is cooled below 42℃. Most pathogens cannot decompose agar. Therefore, it is extremely simple to separate pure bacteria with 1.5 ~ 2.0% agar solid medium, which is still one of the widely used techniques in bacteriological experiments. ⑧ Another student of Koch created a matching board (Petri, R.J.1852 ~1921) to replace the ordinary glass plate created by Koch. When the distribution board is opened, it is easy to operate and ventilate, and it can keep aseptic state.
6.2 Invention of bacterial staining ①1871~1875 and Veigert (c. 1845 ~ 1904) were the first to use industrial cyanine dyes for cell staining. 1877 Koch switched to yaniline dye for bacterial dyeing. Later (1879) and ehrlich shared the methods of wound smear, flame fixation and specimen staining. ② In1882, Koch discovered Mycobacterium tuberculosis by acid-fast staining; ③ 1884 Gram (C. 1853 ~ 1938) invented the differential staining method, which can divide all bacteria into two categories: Gram-positive (purple) and Gram-negative (red). This method has been widely used as the first step to identify unknown bacteria.
6.3 Improvement of Microscope Since 1866, Abbé (E.K.1840 ~1905) and others have actively improved the manufacture of microscopes. Add a light collector to the microscope to make the field of vision bright and clear. Later, it was made into an oil-immersed lens, and achromatic glass lenses were used to identify smaller objects. By 1880, the optical microscope has been very fine, basically the same as today. About 1880, Koch successfully studied microphotography. For example, the spores of Bacillus anthracis are as clear as their propagules, which is beneficial to the preservation and comparative study of bacterial morphological data.
7 bud of artificial immune prevention