After exploration and verification by many production companies, the production process of liquid strains in fermentation tanks is preparation of culture materials-sterilization-cooling-inoculation-fermentation tank culture-inoculation into cultivation bottles. The key technical control points for liquid strain production include the following five points:
1. Preparation of liquid culture medium. The raw materials selected when configuring the culture medium must be rich in nutrients, low in price, stable in quality, and easy to obtain. The particle size of the raw materials should be below 100 mesh, the pH should be appropriate, and a defoaming agent should be added to avoid foam formation.
2. Liquid strain production equipment. Biological fermentation tanks are containers for bacterial growth. Factories generally use airlift fermentation tanks within 1000L. They must not only have a reasonable structure and meet the requirements for mycelial growth, but also be easy to operate, safe to use, and thoroughly sterilized.
3. Culture temperature control. Temperature is a key factor for the normal growth of mycelium. The growth of mycelium is catalyzed by various enzymes. Temperature is an important condition to ensure enzyme activity. During production, the culture medium is controlled by controlling the temperature of the fermentation tank room and sterile air.
4. Ventilation control. At present, airlift fermentation tanks not only provide sufficient oxygen for mycelium during the cultivation process, but also control the size of the mycelial balls and the viscosity of the bacterial liquid through gas stirring. Fermentation tanks of different sizes have slightly different ventilation volumes.
5. Control of miscellaneous bacteria. One tank of liquid culture can generally inoculate tens of thousands of cultivation bottles. Once contaminated, the losses will be heavy. The way to eliminate contamination is to thoroughly sterilize culture materials and fermentation tanks to ensure that there is no bacterial contamination throughout the entire process of liquid strain production. The clean air introduced during the cultivation phase is strictly guaranteed to be water-free, oil-free, and sterile.