1. International background
In the mid-20th century, microbial liquid deep culture (fermentation) technology developed rapidly, thus forming the modern medicine and food fermentation industries. In 1948, American scientists Humfeld and others successfully conducted liquid deep culture of mushrooms, which opened the door to human liquid culture and liquid strain research on edible fungi, and soon made mushroom production in Europe and the United States rapidly advance in the 1950s and 1960s. Entered the era of liquid strains and industrial cultivation.
At present, the world's biological fermentation industry is developing at an alarming rate. The SCP (single cell protein) production tank of British Imperial Chemical Company is 30 stories high, reaching 100m, and the tank capacity is nearly 3500m3. The British edible fungi liquid strain production also represents the strain production model in developed countries in Western Europe and North America. Mushroom strains in the UK use fully automated large tank fermentation to prepare liquid strains, and the national strains are only completed by two international strain companies, Sylvon and Amycel. Agaricus bisporus is an important crop in the UK. Its output value exceeds that of potatoes and tomatoes. It has entered the era of automation and electronic computers and has become a representative of modern agriculture. The strains from its two major strain factories are sold after passing the fruiting inspection.
In recent years, Japan, South Korea and other Asian countries have made in-depth research and application of liquid strains of shiitake mushrooms, enoki mushrooms, and oyster mushrooms. Many mushroom factories have begun to use small and medium-sized fermentation tanks to produce liquid strains for cultivation. .
The overall characteristics of liquid strains and equipment in Western countries are early, precise and large.
2. Domestic background
The earliest people in my country to engage in research on liquid submerged fermentation of edible fungi were Sun Meiyu and others from the Shanghai Institute of Plant Physiology, who conducted research on liquid culture of shiitake mushrooms in 1960. In 1979, Professor Yang Qingyao of Shanghai Normal University began to cultivate liquid strains of shiitake mushrooms, enoki mushrooms, etc. and conduct cultivation experiments. From the 1980s to the 20th century, experts and professors from many scientific research institutes in my country began to conduct repeated, in-depth and arduous research on deep fermentation of edible fungi, liquid strains and small and medium-sized fermentation equipment. It has provided valuable experience and laid a solid foundation for the social promotion and application of liquid strains in my country today, whether in fermentation equipment, process technology or cultivation applications. There are currently more than 50 varieties of edible fungi produced and used in liquid strains, including conventional varieties such as oyster mushrooms, shiitake mushrooms, black fungus, and bisporus mushrooms, and rare varieties such as white mushrooms, king oyster mushrooms, and shimeji mushrooms.
The overall characteristics of liquid strain research in my country are late, complete and small.
3. Gap and way out
Western Europe, the United States, and Japan all have large edible fungus production, advanced fermentation technology and production, and the advantages of their liquid strains are amazing. Incessantly. Why don’t we imitate and copy a set of models and build one or several county-level, provincial-level or national-level liquid culture plants to promote the development of our edible fungi industry? I think there are many reasons, mainly three:
The first is the large investment in foreign equipment and high technical requirements. A set of equipment costs tens of millions of yuan, and requires water, electricity, gas and steam. However, the price of edible fungi in my country is several times to more than ten times lower than the average in the international market. This kind of large, foreign and expensive equipment is not suitable for China's national conditions.
The second is that it is not coordinated with manual farmer production. Liquid strains themselves are industrialized production. While Western countries are developing liquid strains, their cultivation and production have also simultaneously realized mechanization and industrialization. The two complement each other and promote and develop each other. However, the production of edible fungi in my country is still traditional manual, It is difficult to integrate the workshop-style and small-scale farmer production of thousands of households. Moreover, liquid seed production can objectively produce strains year-round, but in actual cultivation, farmers can only cultivate mushrooms seasonally, which is even more inconsistent.
Thirdly, there are too many cultivated varieties in our country. Western countries have only achieved socialized and industrialized production of one or two varieties, and have refined liquid strains. However, there are dozens of varieties of edible fungi in commercial cultivation in my country. There are many difficulties in researching the technology and equipment, and it will take many years. Accumulate and gradually break through.
Exploring liquid strain production technology and equipment suitable for China’s national conditions is the dream of many people with lofty ideals in the edible fungi industry. In particular, the requirements are small scale, low investment, low operating cost, simple technical operation, suitable for multi-variety production, etc. Today we are taking the lead in researching and promoting the liquid strain incubator, which aims at and solves the above problems, and has been recognized by my country's edible fungi industry and practicing mushroom farmers.
1. Advantages of liquid strains
Liquid strains use biological culture (fermentation) equipment to produce edible fungus balls through liquid deep culture (fermentation) as seeds for edible fungus cultivation. The liquid strains are compared to the physical properties of solid strains (sawdust, cotton hulls, wheat bran, branches, etc.). Liquid strains have incomparable advantages over solid strains:
Firstly, the production of seeds is fast: the bacterial cells in the liquid strain culture tank are in optimal temperature, pH, oxygen, carbon-nitrogen ratio and other conditions. Under dynamic conditions, the mycelium divides rapidly and a large number of mycelium (balls) can be obtained in a short period of time. In solid bacterial culture, the mycelium grows uniformly from top to bottom at a natural number speed; while in liquid bacterial culture, the bacterial cells multiply at a geometric multiple. The production of liquid strains using the liquid strain incubator of Dalian Quanhe Fungus Industry Co., Ltd. usually takes 2 to 4 days to complete a culture cycle, while the solid strain needs more than a month to go from the original strain to the cultivated strain at each level. .
The second is strong vitality. Liquid bacteria not only meet the growth needs of the bacteria through controlled environments such as nutrition, temperature, oxygen, pH and alkalinity, but also the metabolic waste gas generated by respiration can be eliminated in time, the metabolism is strong, and the age of all bacteria and cocci is basically the same, so the bacteria Silk has strong vitality. However, the metabolites of solid bacterial cell cells accumulate and mix among the nutrients in the culture medium, which naturally affects the quality of the bacterial cells. Moreover, solid strains often have inconsistent ages on the top and bottom of the bottle (bag). The bottom part has just grown, but the top part may age and lose vitality.
The third is high purity. The mother species used in liquid strains generally need to be prepared through screening and purification, and the purity of the source is high. However, the purity of the slant mother strain used in solid strains has been reduced after unlimited subgeneration by some merchants. Liquid strain culture is operated in a sealed tank, and the air in the oxygen supply system is filtered. Taking the Quanhe Bacteria liquid strain culturer as an example, its purity reaches 99.999999%, thus ensuring that the liquid strain cultured is pure.
The fourth is pollution prevention. The liquid strain is fluid, easy to disperse after inoculation, has many germination points, and germinates quickly after the bacteria ball is inserted. Under suitable conditions, the mycelium will cover the inoculation surface about 24 hours after inoculation, so that cultivation pollution can be effectively controlled. When solid bacterial strains are inoculated, the bacteria are peeled and torn and fumigated with drugs. It usually takes 5 to 7 days from germination and feeding to sealing the inoculation surface. Therefore, there is a high chance of bacterial contamination.
The fifth is to shorten the cultivation cycle. Liquid strains double the speed of cultivation, concentrate fruiting, reduce the number of tides, shorten the cycle, and greatly reduce the costs of cultivation such as labor, energy consumption, and space. Some varieties (such as king oyster mushrooms and enoki mushrooms) take no more than 30 days from seed production to cultivation, harvesting and marketing, making it easier to catch the season and catch up with the market.
Sixth is low cost. Taking the 130-type Quanhe liquid seed production incubator as an example, the cost of each tank of strains is about 100 yuan, and if 4,000 to 5,000 bags are inoculated, the cost of the strains does not exceed 3 cents.
2. Disadvantages of liquid strains
Things are divided into two. Liquid strains currently also have some unsatisfactory qualities. For example, cultivation equipment needs a power supply, remote rural areas often have power outages, equipment requires investment (some mushroom farmers have not completed capital accumulation due to many reasons), and they need to relearn and master the seed production process. If equipment malfunctions, they will not repair it themselves; For large-scale production (1000-2000 bags), it is not cost-effective to purchase equipment, but equipment can be imported from household to household, etc. But these problems are exactly what our scientific research units are trying to solve, and some of them have already been solved. Take the problem of power outage, for example. Currently, the incubator of Quangram Bacteria can continue to run automatically for 10 to 20 hours after a power outage. You don’t have to worry about short-term power outages. Quangram Bacteria is not only responsible for training technology, but also provides door-to-door service when problems arise. This is what scientific research institutions should do. services.
3. Misunderstandings about liquid strains
Because the breakthrough in the research and promotion of liquid strains has been in recent years, and many people’s understanding is still limited to previous years, or even Influenced by the research level of liquid strains more than ten years ago, we are cautious, skeptical and even opposed to the success and application promotion of liquid strains. This is actually caused by our own misunderstandings. The most important ones are as follows:
One is the contamination of the liquid strain training device. Yes, the fermentation liquid is rich in nutrients and can produce bacteria faster than solid wood chips. However, the current internationally advanced membrane filtration materials have a filtration pore size of 0.01 microns, which is a few tenths of the smallest individual bacteria, thereby ensuring the purity of the supply and effectively controlling miscellaneous bacteria.
The second is that the technical requirements for liquid strains are high and difficult for farmers to master.
In fact, our current liquid culture incubators are all automatically controlled and operated by buttons, which is more than ten times easier than the previous production of seed bottles and bags. Farmers can learn it immediately.
Thirdly, it is difficult to store and transport liquid strains. In fact, it only takes 2-3 days to produce one jar of liquid bacterial culture culture. One jar costs 180 yuan, and you can receive several to tens of thousands of bags. It can be used now and used now. Why does it need to be stored and transported? ?
The fourth is the impact of liquid strains on mushroom production. Some people suspect that physical stirring of liquid bacteria causes mononucleation of the bacteria, and that nutrient liquid causes bacterial mutation and degradation, etc. In fact, these problems existed in liquid fermentation many years ago, and they are exactly the problems that our current technology has solved. Gas stirring replaces mechanical stirring, natural organic matter replaces chemical reagents, special mother seeds replace traditional mother seeds, and the shake flask process is eliminated, thereby ensuring the species nature of the strains and ensuring the yield and quality of edible fungi cultivation. continues to this day.
The fifth is the tendency to simplify understanding. This tendency is contrary to the above-mentioned skeptical attitude. It is believed that liquid strains are easy to use, anyone can make the equipment, and the technology is not much. They even confuse the fermentation of strain culture with the same thing. Some people say that a few bottles and plastic bags can be used to produce liquid strains. Some people say that units and individuals buy other people's tanks, dissect them and imitate them, and then tell the scientific research results. Some companies have been established. Within a few days, it was called "strong strength" and "the leader of the industry." Have these people produced or used liquid strains? It is a travesty of science to dare to promote it to the society. (Wang Delin) 1. The backward production method of strains has become a bottleneck affecting the progress of the industry
The traditional three-level and fourth-level transfer of solid strains takes half a year. During production, we are afraid of pollution, aging, smoke and fire, which is complicated. What is good today may not be good tomorrow, and what is good in the East may not be good in the West. It will be fine if you do less work, but problems will arise as soon as the scale increases. Due to the low purity of solid bacterial strains and slow germination, the pollution remains high, and there are countless areas with large-scale pollution. When it comes to fruiting, the mycelium is uneven from bag to bag. Even within the same bag, the age of the mycelium is also very different. The upper hyphae have aged, while the lower ones are not full, making it difficult to concentrate the mushrooms. , product quality is poor and management costs are high.
2. Industrial development requires innovation in bacterial production methods
There are three main trends in the future development of my country's edible fungi industry: one is standardization; the other is factoryization; and the third is annualization. . However, talking about standardization, factoryization, and year-round construction based on solid bacterial strains is tantamount to building castles in the air.
3. Market demand calls for innovation in production methods
According to the China Fungi Association, in recent years, the volume and output value of edible fungi in my country have been declining. Trade declined and RMB 5 billion was lost. According to the China Fungi Association, my country's edible fungi production reached 8.7 million tons in 2002, accounting for 65% of the world's total. So is there an oversupply of edible fungi in my country?
Only by realizing standardized, factory-based, and year-round production can our country develop from a large producer to a powerful producer. To fully realize standardized, factory-based, and year-round production, we must first solve the problems of mechanization and facility-based production. Liquid strains are the source of the entire edible fungi production, and the research and application of liquid strains technology and equipment is the entry ticket to a standardized mushroom factory. It is an undefeated and powerful weapon for the revitalization of my country's fungi industry and its establishment as a powerful country in the international fungi industry. 1. Equipment is becoming more and more sophisticated
First, there are more and more models. There are "family" tanks that produce tens of liters per tank and can inoculate one to two thousand bags, and there are tanks for mushroom and strain factories that produce several hundred liters per tank and can inoculate one to twenty thousand bags. The production and development of edible fungi in our country is in a period of rising. Large ordinary mushroom farmers and large and small mushroom factories (fields) coexist at the same time. Only with multiple equipment models can we adapt to the current development status of edible fungi in our country and suit the national conditions of edible fungi at this stage.
Second, the functions are getting better and better. At present, the Quanhe liquid strain culture machine not only solves the problem of automatic control, but also realizes remote integrated computer monitoring. It is not afraid of power outages. The machine will operate as usual within 20 hours of power outages; it can achieve quantitative inoculation with an error of less than +0.5 ml, and can be compared with fully automatic The liquid strain inoculation machine is connected, and the entire basket (12 bags) can be inoculated at one time and completed in 6 seconds.
2. The technology is becoming more and more advanced
At present, there are forty or fifty varieties of edible fungi that have been artificially cultivated. The medium formulas for the production of these varieties of liquid strains, The culture conditions, processes and equipment controls are different. At present, in addition to completing the seed production process of conventional varieties, the whole grass fungus industry has also made new breakthroughs in some more difficult varieties.
3. Promotion and popularization are in-depth
In the four years since liquid strains have been promoted and applied in my country, edible fungi producers have basically eliminated their suspicion and wait-and-see mentality, and have been recognized by the industry. . Not only has it been promoted and applied in all provinces, cities, and autonomous regions, it has also spread to other countries and regions. At present, Quanhe liquid culture culture equipment has been sold to 18 countries and regions, including Canada, France, Malaysia, South Korea and Taiwan, and has been praised by foreign peers. This is another contribution of my country to the world's edible fungi industry.
4. Liquid strains are moving towards standardization
The China Edible Fungi Association and relevant national departments are strengthening and promoting the standardization of edible fungi and formulating culture media for seed production. , strains at all levels, production processes, production equipment and a series of standards for edible fungi products. At present, the national standards and industry standards for edible fungi liquid strains have not yet been determined, and it is very important for scientific research institutions to formulate and implement enterprise standards. At present, Quanhe liquid strain equipment, technology, strains and inoculation equipment and technology have formulated six corporate standards, which have played an active and effective role in standardizing the promotion and application of liquid strains.