Laboratory fermentation tanks can be divided into ventilated fermentation tanks and anaerobic fermentation tanks according to different needs and anaerobic conditions. Common liquid ventilated fermentation tanks can be divided into mechanical stirring type, air-lift circulation type, bubbling type and self-priming type according to the ventilation mode.

Batch fermentation: This method refers to the fermentation method of adding culture liquid in the laboratory fermentation tank at one time and discharging it at one time after fermentation. After draining, repeat the feeding, sterilization, inoculation and fermentation process. In this process, the growth of bacteria can be divided into four periods: adjustment period, logarithmic period, stable period and decline period.

Fed-batch fermentation: this method refers to the fermentation method of batch fermentation with intermittent or continuous addition of fresh medium. Auxiliary raw materials can be all materials, such as nitrogen source, carbon source, etc. This will prolong the synthesis time of metabolites and so on. This method increased the production efficiency of penicillin by 20%.

Continuous fermentation: This method is related to a fermentation method, which is to continuously discharge the old culture medium and continuously add the culture medium into the laboratory fermentation tank. It has the advantages of high equipment utilization, stable product quality and easy automatic control. Its disadvantage is that it is easy to pollute other bacteria. This technology has been used to produce yeast cells, ethanol, lactic acid, butanol, petroleum dewaxing, sewage treatment, etc.

The laboratory fermentation tank is easy to be disturbed by external conditions during the fermentation process, and it is difficult to carry out sterilization operation during the fermentation process to ensure the health and safety of fermentation products. In the liquid fermentation project, firstly, the sterilizer should be inspected and operated in strict accordance with the relevant sterilization requirements.

1. Check the electrode after installation. First, check all interfaces, external circuits, steam pipes and main valves. The device is completely shut down.

2. At least two people should be present during the sterilization process, one is responsible for the operation of various valves, and the other is responsible for the inspection and reporting of various parameters.

3. After confirming that all valves of the fermentation tank in the laboratory are closed, open the steam generator inlet valve and start the steam generator. First, the steam generator will automatically feed water. At this time, open the drain valve at the bottom. Try to remove the rust on the steam generator. Then close the drain valve. Pay attention to the water level of steam generator to prevent turbulence. At this time, fully open the jacket outlet valve, slowly open the steam generator main valve, slowly open the jacket inlet valve, and start to flow steam into the jacket. At the beginning, the steam pressure is unstable, and the pointer of the pressure gauge may shake violently. Before opening the sampling valve and steam outlet, sampling valve and steam inlet, the jacket inlet valve can be properly closed. The sampling valve and the lower valve are disinfected, and the water vapor with unstable pressure is discharged at the same time.