Liquid strains are relative to solid strains. Liquid strain refers to the strain produced by the rapid growth and reproduction of edible fungus mycelium in a container filled with liquid culture medium under specific culture conditions. Simply put, it is a strain or mycelium that grows in a liquid medium, that is, it is named after the medium in which the mycelium lives. It is to cultivate strains in a fermentor or conical flask, and through continuous aeration, stirring or oscillation, mycelium can be propagated in deep liquid, and a large number of mycelium (balls) and metabolites can be obtained in a short time. The production process of liquid strains is called submerged culture or submerged fermentation in industry.

Advantages:

(1) The process is simple, and there is no classification of liquid strains, which can be used as mother and original seeds, and can also be directly inoculated into cultivation bags as original seeds or cultivated seeds, thus simplifying the production process. (2) Liquid strains with relatively pure strains are produced by modern biotechnology, and the culture of strains is closed and pure, which ensures the purity of strains. (3) The cycle is shorter, from the first-level test tube to the first-level shake flask to the second-level shake flask to the seed tank liquid strain to the bottle (bag) solid. Most varieties of cultivated species only need 1.5 ~ 2 months, which is 1 ~ 1.5 months shorter than general solid strains. (4) The cost of liquid strain is only 2-3 cents, and whether it is used to produce cultivated strain or bag material, it is 1/4- 1/5 of solid strain. (5) The liquid strain with less pollution germinates 6 hours after inoculation, and hyphae cover the surface of the culture material for 24 hours. The germination rate of mycelium exceeds the growth rate of miscellaneous bacteria, and there is no pollution of miscellaneous bacteria. (6) The whole production process of liquid strains is completed in one tank, sterilization and culture are key operations, and only 2 ~ 4 m2 of production space is needed, which not only reduces the production management cost by times, but also saves labor. (7) Liquid strains have a short time to market in order, two months earlier than solid strains. Moreover, the liquid strain culture bag is short, the mycelium is thick, the mushrooms are neat and consistent, and the product quality is good, which is suitable for export requirements. (8) Liquid strains are suitable for industrialized and standardized perennial production, with short culture time and concentrated mushroom production, which is the development direction of edible fungi industry.