- Classification of fermenters by operation mode and analysis of advantages and disadvantages
1) After batch fermentation of medium, inoculate cells in one culture volume and add the method of not adding or replacing medium in the middle.
Advantages: The proportion of contaminating bacteria is small, the operation of the fermenter is flexible, and the production of different products can be carried out.
Disadvantages: low efficiency, difficult design and operation of non-steady-state processes (cell growth, product accumulation, and physical state of the medium often change over time during culture).2) Continuous fermentation During the culture process, fresh medium is continuously added to the reactor, and the culture medium is taken out from the system at the same flow rate, thereby maintaining the culture system in which the cell density, product concentration and physical state are relatively balanced.
Advantages:increase the yield of the target product (the cell culture period is prolonged, resulting in a prolonged accumulation time of the target product); it is convenient for the detection of the fermenter system (after the system enters a stable state, the cell density, matrix, product concentration, etc. tend to be constant).
Disadvantages: The device is more complicated and easy to contaminate miscellaneous bacteria.
- The basic conditions of the fermentation tank and the basic conditions of the fermentation tank are mechanically stirred. The fermentation tank uses the function of a mechanical agitator to fully mix the air and the fermentation liquid, and promote the dissolution of oxygen in the fermentation liquid to ensure the growth and reproduction of microorganisms. Oxygen required for fermentation, also known as universal fermenter. The basic requirements of the fermentation tank are as follows:
1) The structure is tight, can withstand repeated sterilization by steam, the inner wall is smooth, and the corrosion resistance is good, so as to facilitate complete sterilization and reduce the impact of metal ions on biological reactions;
2) It has good Gas-liquid-solid contact and mixing performance and efficient heat, mass and momentum transfer performance;
3) Under the premise of maintaining biological reaction requirements, reduce energy consumption of fermenters;
4) Have good heat exchange performance to maintain biological reactions Optimum temperature;
5) With feasible pipeline ratio and instrument control, it is suitable for sterilization operation and automatic control.