What is the difference in production between fermenters and shake flasks?
The fermentation scale and spatial environment differ, and the fermentation tank volume is relatively large, ranging from a few cubic meters to several hundred cubic meters. This large-scale fermentation can process a large amount of fermentation broth at once, achieving a high total yield.
For example, in the industrial production of antibiotics, large fermentation tanks can hold several tons of fermentation medium. By controlling the fermentation conditions reasonably, a large amount of antibiotic products can be harvested.
The environment inside the fermentation tank is relatively stable and can provide uniform conditions such as temperature, pH, and dissolved oxygen. It can precisely adjust these parameters through stirring devices, ventilation systems, etc., so that microorganisms are in a relatively suitable environment throughout the fermentation process, which is conducive to microbial growth and product synthesis.
For example, by adjusting the stirring speed and ventilation rate, it can ensure that microorganisms in various parts of the fermentation tank can obtain sufficient oxygen, thereby improving fermentation efficiency.
The shaking bottle has a small volume, usually ranging from tens of milliliters to several liters. This limits its fermentation scale, and the amount of product that can be obtained from each fermentation is relatively small.
For example, when conducting preliminary screening of microbial metabolites in the laboratory, shaking flasks of 250ml or 500ml are commonly used, and the resulting fermentation products may only be sufficient for preliminary component analysis and activity testing.
The uniformity of the environment inside the shaking bottle is relatively poor. During the shaking process of the shaker, although it can mix the culture medium and microorganisms evenly to a certain extent, compared with the fermentation tank, its control accuracy for temperature, dissolved oxygen and other conditions is lower.
For example, microorganisms near the bottle wall and center in a shaking bottle may grow differently due to differences in temperature and dissolved oxygen.
Fermentation tanks with different oxygen supply capabilities are usually equipped with efficient ventilation systems, such as air filters, distributors, etc. Air can enter the fermentation broth evenly through the distributor, and under the action of the stirrer, bubbles can be fully dispersed in the fermentation broth, allowing microorganisms to fully contact oxygen.
For example, in the process of aerobic microbial fermentation to produce amino acids, the fermentation tank can maintain the dissolved oxygen level within the optimal range required for microbial growth and product synthesis by precisely controlling the aeration rate and stirring speed, thereby increasing the yield of amino acids.
Some advanced fermentation tanks also use special oxygen supply technologies, such as pure oxygen aeration and oxygen enriched aeration, to further increase the dissolved oxygen concentration in the fermentation broth, thereby promoting microbial growth and product synthesis.
This efficient oxygen supply method can meet the oxygen demand of microorganisms in high concentration and high activity states, which helps to improve fermentation yield.
The shaking bottle mainly relies on the shaking of the shaker to allow air to enter the fermentation broth. When the shaking bottle swings on the shaker, the liquid forms a wavy motion inside the bottle, causing air to come into contact with the surface of the liquid, thereby achieving a certain degree of oxygen transfer.
However, this oxygen supply method is relatively limited. On the one hand, the bottle mouth of the shaking bottle is small, which limits the amount and speed of air entering; On the other hand, as the concentration of microorganisms in the fermentation broth increases and metabolic activity intensifies, the demand for oxygen rapidly increases. The oxygen supply method in shake flasks may not be able to meet the needs of microorganisms, thereby limiting the fermentation yield.
In practical applications, the yield of fermenter fermentation is usually much higher than that of shake flask fermentation, which may be several times, tens of times, or even higher. However, the specific yield differences still need to consider various factors such as microbial species, fermentation product types, and fermentation conditions.
In the laboratory research stage, shake flask fermentation is commonly used for strain screening and preliminary optimization of fermentation conditions due to its advantages of simple operation and low cost; In industrial production, fermenter fermentation is the main way to achieve large-scale and efficient production.
