What is the difference between solid and liquid strains of edible fungi? What are the advantages and disadvantages of liquid strains?
First, how to classify the strains of edible fungi?
In production, we generally divide edible fungi into three grades, namely, primary species, secondary species and tertiary species. The first kind is also called mother seed, the second kind is called original seed, and the third kind is called cultivated seed. Details are as follows.
1. Main species-mother species
In addition to the mother species, the first-class species can also be called slant strains and test-tube strains. It refers to the pure culture and subculture of fruiting body mycelium obtained by different methods, and glass test tubes are usually used as culture containers and use units. According to different production purposes, the original seed can be divided into preservation seed, propagation seed and production seed.
Under normal circumstances, the pure hyphae of the mother species are fertile, but due to the limited number of mother species obtained, we will transfer the hyphae to a new slant culture machine to obtain more mother species. This kind of mother seed is called regenerative mother seed, and usually one mother seed can be transformed into 10 regenerative mother seed.
What is the difference between solid and liquid strains of edible fungi? What are the advantages and disadvantages of liquid strains?
2. Secondary Species-Primitive Species
The so-called secondary species refers to the pure culture of mycelium propagated on the basis of the mother species. Generally speaking, the culture medium mainly includes natural solids, such as grains, sawdust and dung. In principle, secondary species can be used for direct cultivation or for secondary cultivation of tertiary species. In the production process, it is generally based on actual needs.
The culture containers and users of secondary strains can directly use glass bottles, plastic strain bottles or polypropylene plastic bags. However, the specifications of each container are not exactly the same. For example, if a glass bottle is used, it is best to use 650~750 ml. If a plastic strain bottle is used, it is generally 850 ml. If a plastic bag is used, its specification is 15×28 cm.
What is the difference between solid and liquid strains of edible fungi? What are the advantages and disadvantages of liquid strains?
3. Third-level species-cultivated species
The third kind is the last kind of edible fungi, which is also directly used for production and cultivation, so it is also called cultivated species. Usually, it is propagated by original seeds on natural solid medium, which includes grains, sawdust and grass. General cultivated species can only be used for production and cultivation, and can not further expand the propagation of finished products. The culture container and using unit for cultivating seeds are generally transparent glass bottles, plastic bags or plastic bottles. In the actual production process, you can choose freely according to the cost and demand.
What is the difference between solid and liquid strains of edible fungi? What are the advantages and disadvantages of liquid strains?
2. What are the kinds of edible fungus strains?
Generally speaking, there are two kinds of cultivated edible fungi, one is solid strain and the other is liquid strain. In production, there are many kinds of solid strains and their applications are wide. Compared with fixed strains, liquid strains have their own advantages. Next, we will introduce these two strains in detail.
1. solid strain
Usually, as long as it is an edible fungus strain growing on a solid medium, it can be called a solid strain. Solid strains can be divided into the following types in production: PDA test-tube strains, grain strains, cottonseed hull strains, sawdust strains, compound strains and so on. The advantages and disadvantages of different types are not exactly the same. In the production process, you can choose the appropriate strain type according to your actual needs and local conditions.
What is the difference between solid and liquid strains of edible fungi? What are the advantages and disadvantages of liquid strains?
Grain strain is a strain with the seeds of wheat, corn, sorghum and other crops as the culture medium. Its advantages are vigorous growth of mycelium, strong vitality, rapid growth of bacteria and rapid expansion in the matrix. Agaricus bisporus basically uses grain strains. However, there are also some shortcomings, that is, the storage time of strains should not be too long, otherwise it is easy to age.
Cottonseed hulls are rich in nutrients and dispersed in particles, so the biggest advantage of the produced strains is their strong anti-pollution ability and high temperature resistance. The main characteristics of sawdust strain production are simple production process, low cost, wide source of raw materials and convenient packaging and transportation.
As for PDA test-tube strain, it is a pure culture obtained by spore separation or tissue separation, and it is a pure mycelium strain obtained by transplanting it into test-tube slant culture medium. Compound strain is an edible fungus strain made of two or more main raw materials as culture medium. Its advantages are rich and comprehensive nutrition, good mycelium growth and strong adaptability after inoculation.
What is the difference between solid and liquid strains of edible fungi? What are the advantages and disadvantages of liquid strains?
2. Liquid strain
Liquid strain is a kind of liquid edible fungus strain produced by survival culture technology in biological fermentor with liquid culture medium. This kind of strain adopts biological fermentation engineering technology, which was not available in the traditional strain production field in the past. The emergence of liquid strains was in the 1950s. It can be said that liquid strain is more like the product of modern science and technology than traditional solid strain. Liquid is a physical state of culture medium, just like solid strain, because solid is also a physical state.
The earliest time to study and cultivate liquid strains in China can be traced back to 1960. 1979, relevant experts began to cultivate liquid strains such as Lentinus edodes and Flammulina velutipes, and achieved certain success. However, the time to really popularize liquid strains and make a breakthrough began at the beginning of 2 1 century. In production, liquid strains are not divided into three grades like solid strains, and can be used as mother strains to produce original strains or directly cultured as cultured strains.
What is the difference between solid and liquid strains of edible fungi? What are the advantages and disadvantages of liquid strains?
3. What are the advantages and disadvantages of liquid strains compared with solid strains?
1. Advantages of liquid strains
The traditional production technology of solid edible fungus strains is complex, long in production cycle and high in cost. More importantly, the traditional edible fungus production is almost entirely controlled by experience, and the success of edible fungus strain production is closely related to the experience of technicians. But it has obvious advantages in liquid strain production.
First, the production cycle is short. The bacterial cells in the liquid culture tank are in the most suitable conditions, which can be properly controlled, and the culture cycle is short, which usually takes only 2~4 days to complete. It takes at least 1~2 months for the solid strain from the original strain to the cultured strain. It can be said that the seed production time of liquid strain is only about110 of solid strain.
Second, the production cost is low. To a large extent, liquid strains rely on mechanical equipment to realize automatic seed production, while solid movement is mainly controlled by manual work, and in many cases it is manual workshop production at home. As we all know, the labor cost is very expensive now. According to the actual calculation, the seed production cost of liquid strain is only 1/30 of that of solid strain.
What is the difference between solid and liquid strains of edible fungi? What are the advantages and disadvantages of liquid strains?
Third, it has strong vitality and high purity. Liquid strains can adjust the environment such as nutrition, temperature, oxygen and pH, and can meet the growth needs of bacteria to the greatest extent. Moreover, the mother species used by liquid strains need to be screened and optimized, with high provenance purity and strong mycelium vitality. The highest purity of liquid strain can reach 99.99%, which is higher than that of solid strain. Moreover, the accumulation of metabolites in solid bacteria cells can easily lead to poor overall quality and weak vitality.
Fourth, automation has less pollution. Liquid strains are automatically produced by fermentation engineering technology and special seed production equipment, and there is almost no need for manual participation in too many technical links, and the degree of automation is very high. However, the production of solid strains depends entirely on manual experience, with low degree of automation and low utilization rate of mechanical equipment. In addition, due to the short germination time and high speed of liquid strains, they can germinate in the shortest 6 hours after inoculation, so the chance of mixed bacteria infection is very small. Solid strains germinate for a long time and slowly, usually taking at least 5~7 days, so they are easily infected by miscellaneous bacteria.
What is the difference between solid and liquid strains of edible fungi? What are the advantages and disadvantages of liquid strains?
Fifth, the cultivation period is short. Compared with solid strains, the spawning speed of liquid strains is at least twice as fast, and the fungus bags are uniform up and down, and the mushrooms are concentrated, which can reduce the number of tides and the overall culture cycle is relatively short. When liquid strains are used for culture, all planting costs will be greatly reduced, no matter in labor, energy consumption or site. More importantly, due to the short cultivation time, we can better grasp the market and obtain more economic benefits.
What is the difference between solid and liquid strains of edible fungi? What are the advantages and disadvantages of liquid strains?