For thousands of years, the working people of our country have made many major inventions and creations in understanding and utilizing microorganisms; in the treasure house of civilization of the Chinese nation, they are like crystal pearls, radiating the wisdom of the Chinese people The brilliance of ingenuity.
Here, we intend to talk about some of the major achievements in microbiology related to industry and agriculture in ancient my country.
Unique koji making and brewing
According to historical records, the history of brewing in my country is at least four to five thousand years. Among the oracle bone inscriptions of the Shang Dynasty unearthed from the Yin Ruins, there are characters that are similar in shape to modern Chinese characters. The remains of a brewing workshop discovered in the Yin Ruins prove that my country's brewing industry was already quite developed as early as more than 3,000 years ago.
Making wine from grains requires two main processes: decomposing starch into glucose (saccharification), and then converting glucose into alcohol and carbon dioxide (alcoholic fermentation). In the books describing the history of the Yin and Shang Dynasties, there are words such as "If you make alcoholic aldehyde, you are only a qu tiller" ("Shang Shu Shuo Ming Xia"), indicating that grains with microorganisms (qu) and germinated grains (qu) were used in brewing at that time. tiller). However, before the Han Dynasty, only koji was used to make wine. At that time, due to certain favorable conditions being used when making koji, the koji should contain a large amount of mixed growing molds and yeasts, which played the roles of saccharification and alcoholic fermentation respectively. Using this kind of koji to make wine, the two processes of saccharification and alcohol fermentation can be carried out continuously and crosswise. Today this method is called compound fermentation. This is a great invention made by the working people of our country in the brewing industry. The world-famous rice wine "Shanniang" and the liquor "Moutai" produced in my country, which have unique flavors, are both famous wines produced by the continuous development of the compound fermentation method. In ancient times, wheatgrass was used to brew beer in the West. To this day, the main grain wines in Western countries are still made by saccharifying malt and adding yeast for alcoholic fermentation (such as whiskey, vodka, etc.). At the end of the 19th century, Europeans learned about this unique method in my country after studying our country's distiller's yeast, and called it "starch fermentation method".
In "Book of Rites·Yuejin·Midwinter Chapter", six wine-making requirements are proposed. The general idea is: the grains used must be prepared, the production of Qu Ni must be timely, the rice soaked and steamed must be clean, The water must be clear and odorless, the pottery must be fine, and the temperature must be properly controlled. In Volume 5 of "Zhou Li", "Tiangong Jiazai Xia", there are also records of wine names such as "Wu Qi" and "Three Wines". We can think that "Wuqi" refers to the five stages in the wine-making process, and "Three Wines" refer to several different types of wines produced by fermentation. This fully shows that as early as 3,000 years ago, people had already carefully observed the brewing of Quzhi, had a certain understanding of the growth and development rules of microorganisms in Quzhong, and the brewing technology has been quite advanced.
At the end of the Eastern Han Dynasty, Cao Cao (155-220) once proposed to Emperor Shangshu a "Nine Brewing Method", which is a method of continuous feeding. This can prevent excessive sugar from inhibiting fermentation, and the resulting wine will naturally be more mellow. To this day, rice wine in Jiangsu and Zhejiang areas of my country is still made using this method. It should be pointed out that this method summarized two thousand years ago is based on the same principle as the method of continuous feeding or adding raw materials multiple times during the fermentation process (that is, fed-batch) in today's fermentation industry.
It can also be seen from ancient Chinese books about koji making and wine making that our country already had many fermentation technology creations a long time ago, such as using physalis to regulate fermentation, and heating and sterilizing to prevent the wine from aging. Deterioration, add wax or oil to eliminate foam, etc.
In terms of making koji and brewing wine, red koji should be mentioned in particular. This is a major invention of the working people of our country. According to historical records, the emergence of red yeast rice was not later than the tenth century AD. A poet from the Song Dynasty once wrote a poem that said, "Fujian wine is as red as red when you pour it at night." This shows that wine made from red yeast rice was quite common in the Song Dynasty. In long-term production practice, people have learned to treat rice with alum to maintain acidity, add water in stages to adjust aeration, and adjust temperature with time, so that it has acid resistance, heat resistance, hypoxia resistance, and both saccharification and Monascus with alcohol fermentation ability can grow through the inside and outside of rice grains, which fully demonstrates the superb technology of cultivating microorganisms at that time. Red yeast rice is a specialty of my country. It can not only make wine, but is also a harmless food dye and can be used for medicinal purposes.
The use of Qu to treat diseases has been recorded as early as the Spring and Autumn Period. As recorded in "Zuo Zhuan", in the twelfth year of Lu Xuangong (597 BC), Shen Shuzhan asked Huan (xuán) Wushe: "Is there any wheat music? He said no." Shuzhan said: "The river fish has a belly disease, what can I do?" But specifically Records of the production of medicinal koji were first seen in the book "Spring and Autumn Wei" of the Liang Dynasty (502 to 557 AD) during the Southern and Northern Dynasties. The book said: "Wheat yin is also the same as millet yang. First soak the koji and then add the millet. When yang and yin are combined, it boils. In later generations, qu was used as medicine, so it was used to treat diseases." In the Ming Dynasty, medicinal qu was called "divine song". Today, Shenqu is still a commonly used folk medicine for digestion, promoting qi, strengthening the spleen and nourishing the stomach.
In the long process of development of koji-making technology, various types of koji have been developed specifically for making vinegar, making sauce and pickling food.
Vinegar making is the further oxidation of alcohol into acetic acid. In the West, it is made by acetic acid fermentation using wine as raw material. There is a record of "醯人" in Volume 6 of "Zhou Li". "醯" was the vinegar at that time, which shows that our country knew how to make cold wine at least 2,500 years ago.
By the late Northern and Southern Dynasties (sixth century AD), solid fermentation of vinegar using grains as raw material had begun to sprout. Later, vinegar was brewed directly from grains. The use of grain solid fermentation to make vinegar is a characteristic of my country's vinegar-making method. Due to the variety of microorganisms in the koji, in addition to acetic acid, the vinegar also contains organic acids such as lactic acid and gluconic acid, so the vinegar has a better flavor.
Making sauce uses the protease produced by microorganisms in koji to decompose the protein contained in a large amount in foods such as beans and meat into hydrolyzates such as amino acids. This is the first of its kind in our country. According to the record in Volume 4 of "The Rites of Zhou", "The food and drink of the king of the dining room is shameful... there are hundreds and twenty jars of sauce." It can be seen that sauce also appeared roughly 2,500 years ago. "Practical Soy Sauce Brewing Method" written by Kinoshita Asakichi of Japan says: "In the sixth year of Tianhu Shengbao, Tang Monk Jianzhen came to the court and introduced the miso making method." "Miso" means sauce. The sixth year of Tianping Shengbao was 755 AD. Jianzhen (688-763) traveled to Japan in the twelfth year of Tianbao of Tang Dynasty (753 AD). It can be seen that the Japanese sauce-making method was passed from my country to China at that time.
With the development of koji-making technology, people have a deeper and deeper understanding of microbial activities and their observations have become more careful.
There have been many records of observing microbial activities in ancient my country, and some methods are similar to those used in modern microbiology. Therefore, the quality of koji continues to improve, the types increase, and the uses become increasingly specific.
For example, as early as the Zhou Dynasty, the yellow dress worn by the queen was called Quyi. This shows that Aspergillus flavus had a significant advantage in the Quyi at that time, giving the Quyi a beautiful yellow color. ——In the Eastern Han Dynasty, in some brewing methods, the amount of koji used has been reduced from tens of percent to a few percent, which shows that the use of koji has changed from a saccharification starter to a strain that reproduces the required microorganisms. . If the microorganisms in the koji are not quite pure, it will be difficult to ensure the success of brewing.
In the Jin Dynasty, there are already records of adding Chinese herbal medicine to koji. For example, Zhihan's "Southern Grass and Trees" records the koji-making methods of Guangdong and Guangxi: "Pestlet powder is mixed with many grass leaves to treat kudzu juice. It is as big as an egg, placed in basil, and made after menstruation. The user combines the glutinous rice into wine. "Because Chinese herbal medicine contains certain vitamins that help microorganisms grow, the microorganisms in the song can grow better and brew." Wine also has a special flavor.
In the Northern Wei Dynasty, the form of music was almost all "cake music". This kind of koji is conducive to the growth of Aspergillus on the outside, but conducive to the reproduction of Rhizopus and yeast on the inside. By the Song Dynasty, the so-called "passing coolness" method of applying excellent old songs to the surface of the raw music before cultivation was known. This is similar to today's vaccination operation, and the quality of the song is easier to ensure.
It is through thousands of years of selective breeding that there are many strains of bacteria with extremely strong production capabilities in our country. For example, Rhizopus in Xiaoqu has a rare strong saccharification ability.
The book "Essentials of Qi Min" written by Jia Sixie of the Northern Wei Dynasty is an outstanding ancient agricultural science work that has been completely preserved. In terms of microbiology, this book is also rich in content. It records many important historical facts about the application of microbial knowledge in agriculture and rural handicrafts in my country at that time, and some of them have been upgraded to a more systematic understanding of laws. It is an important classic in the history of microbiology. For example, it is proposed in the book that the standard for the maturity of koji should be that the koji is covered with various bacteria, the so-called "five-color clothing"; the formation of acetic acid is linked to the membrane (coat) formed by the acid bacteria, and he realizes that "Clothing" is a living substance. The book also points out that white fermentation (probably a membrane formed by rough-film yeast) is harmful to vinegar making. Jia Sixie used vivid language such as "fish-eye soup is boiling" to describe the phenomenon of carbon dioxide release during alcohol fermentation. It should also be pointed out that the koji made from wheat grains (huangyi), flour koji (yellow steamed) and sprouted grains (tillers) used in making sauce are discussed together in one chapter, which shows that At that time, the intrinsic connection between the three was realized. Now it seems that these are all related to hydrolytic enzymes that hydrolyze protein and starch. It can be said that the author already has an awareness similar to today's "enzyme preparations".
Finally, it should be pointed out that the use of starchy raw materials to make koji created by the working people of our country thousands of years ago is a good way to use solid cultures to preserve microorganisms. Because under dry conditions, microorganisms are in a dormant state and their activity tends to remain unchanged. The principles underlying this approach are still applied today.
Using fertilizers and nourishing soil - using microorganisms to improve soil fertility. As early as the Spring and Autumn Period and the Warring States Period, people already knew that rotten weeds in the fields could make crops grow lush, and they also knew how to use rotten weeds and dung for crops. Fertilizer. We know that decay is the result of microbial activity, so in fact, microorganisms were already being used to improve soil fertility.
Rhizobium bacteria on the roots of leguminous plants have the ability to fix nitrogen in the atmosphere. Therefore, leguminous plants play an important role in improving soil fertility. In the "Book of Si Sheng" written in the late Pre-Han Dynasty (first century BC), the method of intercropping melons and adzuki beans was mentioned. In the book "Guangzhi" written by Guo Yigong of the Western Jin Dynasty at the end of the third century AD, there are already records of cultivating milkvetch as green manure in rice fields. The book says: "Ming, the color of the grass is green and yellow, with purple flowers. It is planted under the rice in December. It spreads in the prosperous Yin Dynasty. It can make the fields beautiful and the leaves are edible."
"The "sweet potato" mentioned here is milkvetch, also called red flower grass. By the sixth century AD, the book "Qi Min Yao Shu" of the Northern Wei Dynasty had already compared different crop rotation methods, with special emphasis on using beans to protect the grain. The book says: “In all grain fields, the bottom of mung beans and adzuki beans is at the top.” “In all millet fields, the bottom is newly opened land, followed by soybeans and beans at the bottom. . "This shows that there was already a cereal farming system that rotated or intercropped with legume crops. It was not until the 1830s that Britain had a crop rotation system, and other European countries such as Germany and Russia planted green manure on a large scale.
For a long time, Chinese farmers have known to move the soil where leguminous plants have been planted for many years to the fields where new beans are planted to ensure the good growth of newly planted beans. People call this method ". It now appears that this is actually the inoculation of rhizobia. This is the germination of the use of bacterial fertilizers in modern times. Farmers in the Chengdu Plain of my country have long adopted a method of inoculating rhizobia, which is to inoculate the soybeans after harvesting them. , mash the soybean roots together with the root nodules and soil, mix them with a small amount of plant ash, knead them into small balls, and wrap them with straw to prepare the soybeans for seed dressing the next year. This is a further development of the "Ketu method" and is actually the original one. Bacterial fertilizer.
Ancient China’s achievements in understanding and utilizing microorganisms were huge.
In addition, there were also valuable creations and inventions in ancient China regarding the treatment of rabies and the use of vaccination.