There are mainly two methods for the production of edible fungus strains: solid strains and liquid strains. For a long time, the strains used in the production of most edible fungus varieties are solid strains, mainly because the requirements for equipment are low, and they are easy to transport. However, there are also disadvantages such as long production cycle, high cost of strain production, inconsistent bacterial age, and irregular fruiting.
With the joint efforts of the vast number of scientific and technological workers and production enterprises, the liquid strain technology developed by innovation has gradually matured. It has the advantages of short production cycle, low labor cost, strong mycelium vitality, consistent bacterial age, neat fruiting, and shortened cultivation time. It provides good provenance conditions for the development of edible fungi industrialization, and is widely used in various varieties of edible fungi. In particular, liquid strains have been widely used in some large shiitake mushroom and black fungus packaging factories, which has greatly promoted the development and growth of the industry, and the technical quality has been greatly improved.
Edible mushroom liquid strains have the following characteristics:
1. The speed of liquid strain seed production is fast and the fermentation time is short, which greatly improves work efficiency and saves labor.
The mycelium of the liquid strain in the fermenter is always under the most suitable temperature, nutrition, oxygen, pH and other conditions, and the mycelium grows geometrically. It divides in a short period of time and proliferates a large number of mycelia. Generally, it takes 5 to 7 days to complete a growth cycle. Using liquid strains to inoculate the culture medium, the strains are evenly distributed and cover the entire material surface, which promotes rapid growth of bacteria, shortens the cycle, and greatly reduces the costs of labor, energy consumption, and space for cultivation.
2. Reduce the contamination of bacteria after inoculation.
The fluidity of the liquid bacteria is good, and the use of reasonable inoculation equipment can make the liquid bacteria spray on the entire material surface of the medium. Rapid germination at multiple points in a short period of time (general varieties can be observed with the naked eye within 24 hours) makes the entire material surface covered with hyphae, which greatly reduces the erosion of the medium by miscellaneous bacteria, thereby reducing the pollution rate.
3. The bacterial age is consistent and the vitality is good.
The liquid bacteria can get sufficient nutrition in the fermenter, and the growth environment does not fluctuate. The mycelium grows in the tank with sufficient oxygen, so that the liquid bacteria are always in the most vigorous growth state, and the fermentation time is short, so the mycelium has strong vitality and the age of the bacteria is consistent.
4. The cost of liquid bacteria is low.
The cost of liquid strains is low, and it greatly saves labor for seed production and inoculation. Taking the inoculation of 40,000 bags as an example, the working time is 8 hours, and the solid strains require about 12 to 16 people. The liquid strain can be easily completed by only 6 people, and only 2 people can be completed if an automatic inoculation machine is used.
5. The storage time is short.
The liquid strains should be used in time after the fermentation is completed, and should not be stored for a long time, even if stored at 2-5°C, it should not exceed one week. The mycelium divides fast, and the time in the tank is too long, which will easily cause excessive mycelium and insufficient nutrition, accelerate the aging of the bacteria, stratify, form a thicker bacteria skin, and block the bacteria-exiting valve.