1Stainless steel biological fermentation tankCleaning and Disinfection: Building a Foundation for Aseptic Operations

Preliminary cleaning and rinsing

Use soft brushes or mechanical cleaning equipment to remove residual culture medium, impurities, and biofilms from tanks and pipelines.

Rinse with clean water until there are no visible residues, ensuring that the subsequent disinfectant can fully contact the surface.

Chemical cleaning and disinfection

Alkali washing: 1% -2% sodium hydroxide solution is circulated for cleaning, dissolving organic matter (such as proteins and polysaccharides) at a temperature of 60-80 ℃ for 30-60 minutes.

Acid washing: Neutralize alkaline residues and remove inorganic salts with 0.5% -1% dilute hydrochloric acid for 20-30 minutes.

High pressure water gun flushing: using a rotating nozzle (pressure>50 bar) to impact dead corners, the efficiency is increased by 50% compared to traditional brushing.

Chemical disinfection: Soak or spray hydrogen peroxide compound disinfectant (such as Novofon, 3% -5%) for 30 minutes to kill 99.999% of bacteria, spores, and bacteriophages.

Final processing and validation

Rinse with sterile water until there are no disinfectant residues, and dry the tank with sterile air.

Regularly monitor microbial load (such as cotton swab sampling) to ensure a reduction of over 90% in bacterial infection rate.

2、 Sterilization: Ensure a sterile environment

Actual consumption operation (taking 121 ℃ and 30 minutes as an example)

Pre heating stage:

Close all valves, open the steam outlet and exhaust valve to release cold air.

Slowly open the jacket steam valve and wait for the temperature to rise to 50 ℃ to detect the steam reaching its position.

Adjust the condensate drain valve to "fine adjustment" and start stirring to evenly heat the culture medium.

Rapid heating stage:

When the temperature reaches 90 ℃, reduce the opening of the jacket inlet valve and open the condensate drain valve next to the inlet air valve.

When the temperature reaches 121 ℃ and the pressure is 0.1MPa, loosen the inoculation cap until 4 small holes emit steam, and hold for 30 minutes.

Insulation and cooling:

Close the bottom valve of the tank, adjust the inlet air valve and exhaust valve to maintain pressure.

Cool to fermentation temperature with air (filter pressure 0.12-0.15MPa) and circulating water (open the inlet air valve when the temperature drops to 105 ℃).

critical control point

Ensure that steam fully contacts all parts and avoids disinfection blind spots.

Maintain positive pressure inside the tank during cooling to prevent negative pressure from inhaling unclean air.

3、 Vaccination: Strict aseptic operation

Preparation before vaccination

Reduce the tank pressure to ≤ 0.02MPa, loosen the inoculation port cover and place a flame ring (with cotton added to assist combustion).

Pre shake the seed solution until it reaches the logarithmic growth stage, with an inoculation amount of 5% -10% (adjusted according to the strain).

Aseptic inoculation process

Ignite the flame ring, open the inoculation cap, quickly pour in the seed solution, and then tighten the cap.

Immediately increase the tank pressure to 0.05-0.1MPa to prevent backflow of miscellaneous bacteria.

environmental control

Close workshop doors, windows, and exhaust fans to reduce air flow.

Operators should wear sterile clothing, gloves, and masks to avoid direct contact with the vaccination site.

4、 Fermentation control: precise regulation of parameters

Parameter setting and monitoring

Temperature: Maintain the set value (such as 37 ℃± 0.5 ℃) through a jacket cooling/heating system.

PH: Automatically add acid (dilute hydrochloric acid) or base (sodium hydroxide) dropwise to adjust to the target value (such as pH 7.0).

Dissolved oxygen (DO): Adjust the stirring speed (100-600 rpm) and ventilation rate (0.5-2 VVM) to maintain DO ≥ 30% saturation.

Pressure: Maintain a tank pressure of 0.05-0.1MPa to increase oxygen solubility and prevent bacterial contamination.

Process sampling and recording

Record parameters such as pH, DO, temperature, and tank pressure every hour.

Take samples and send them for inspection according to the process requirements, and simultaneously conduct microscopic examination to observe the morphology of the bacterial cells.

exception handling

Too much foam: automatically add defoamer (such as polyether).

Equipment failure: Immediately activate the backup system, record the time of failure and parameter changes.

5、 Material release and cleaning: ensuring equipment reusability

Fermentation ends and material is released

Close the mixing and ventilation system, open the bottom valve of the tank and release the material smoothly.

The fermentation broth is transported to downstream processing equipment such as centrifuges and filters.

Tank cleaning and maintenance

Rinse the residual fermentation broth with clean water, remove organic matter with alkaline washing (1% NaOH), and neutralize alkaline residue with acid washing (0.5% HCl).

Check the wear and tear of components such as agitator blades, valves, sensors, etc., and replace damaged parts in a timely manner.

After the tank is dried, it should be stored in a ventilated environment to avoid rusting.

VIStainless steel biological fermentation tankThe core value of standardized operations

Reduce the risk of bacterial infection: By constructing a triple barrier through chemical cleaning, high-pressure rinsing, and hydrogen peroxide disinfection, the bacterial infection rate is reduced by over 90%.

Improve fermentation efficiency: Accurately regulate temperature, pH, DO and other parameters to shorten the fermentation cycle by 5% -15%.

Extend equipment lifespan: Regular maintenance and standardized operation reduce corrosion and wear, and lower maintenance costs by over 30%.