BioVita G Bioreactor Operating Procedure

Scope: This procedure applies to the daily operation, sterilization, and inoculation processes of bioreactors.

1. Pre-Operation Inspection

Before starting the system, carefully check the following equipment and connections:

Chiller

Air compressor

Bioreactor

Inlet and outlet water pipes and gas pipes

2. Startup Procedure

Turn on the switches on each unit in sequence.

Finally, turn on the main switch at the back of the unit.

3. Shutdown Procedure

On the controller, set all unit parameters to OFF.

Open the air inlet switch, then shut down the system.

Turn off the equipment in the following order:

First, turn off the switch behind the controller.

Then, turn off the switches on other units.

4. Sterilization Procedure

4.1 Equipment Preparation

Remove the motor, place it flat on the table, and cover the top of the bioreactor with a protective cap.

pH Electrode:

Disconnect the cable and cover it with a red protective cap.

Insert the pH electrode fully and tighten the upper and lower fixing nuts.

Calibrate before sterilization (see section 4.2 pH Electrode Calibration).

DO Electrode:

Disconnect the DO cable, wrap the connector with aluminum foil, and cover it with a black protective cap.

Insert the DO electrode fully and tighten the upper and lower fixing nuts.

Calibrate after sterilization (see section 6.2 DO Electrode Calibration).

Antifoam or Liquid Level Electrode:

Disconnect the cable and insert it fully.

After sterilization, position it at the required height (antifoam electrode should be 1.5 cm above the liquid surface).

Piping Disassembly:

Disconnect the inlet and outlet water pipes from the fermenter and condenser, and clamp the connectors to prevent water leakage.

Clamp both ends of the filter and wrap the outlet with aluminum foil.

After fermentation, check if the filter is wet. If liquid remains, use a suction bulb to remove it.

Harvest Tube:

Clamp the silicone tube to prevent liquid leakage during sterilization.

Stirrer Blade Adjustment Before Sterilization:

Bottom blade should be close to the air distributor.

Upper blade should be adjusted to the middle of the fermentation liquid.

Sampler:

Position it in the middle, away from the baffle.

Before sterilization, remove the suction bulb and ensure the silicone tube does not touch the autoclave wall.

Before Sterilization:

Loosen six fixing nuts for venting, keeping other nuts tightened.

Immediately tighten the nuts after sterilization, using gloves to prevent burns.

4.2 pH Electrode Calibration

After connecting the cable, loosen the first fixing nut of the electrode.

Remove the pH electrode, rinse with deionized water, and gently blot dry with tissue.

Calibrate using standard solutions in sequence:

4.01 solution → Once the controller reading stabilizes, enter 4.01 in the Set Zero field.

7.00 solution → Once the controller reading stabilizes, enter 7.00 in the Set Span field.

Do not turn off the controller after calibration.

5. Post-Sterilization Recovery

Tighten the loosened fixing nuts and seal the acid/base bottles.

Remove the aluminum foil from the filter and release the silicone tube clamp.

Reinstall the motor, applying a small amount of petroleum jelly if the lubricant has dried.

Reconnect the DO electrode and perform DO electrode calibration.

When the temperature drops to the set value, reconnect all water pipes, pH cables, and antifoam cables.

Insert the temperature probe, ensuring it is fully inserted.

Check the output pressure of the air compressor, which should be 0.7–1.0 kg/cm³.

6. Inoculation Procedure

Move the tubing near the inoculation port aside and use a metal shield around the inoculation area.

Spray alcohol around the inoculation port and ignite it.

Process inoculation tools as follows:

Inoculation loop: Dip in alcohol, ignite, and place over the inoculation port.

Wrench or pliers: Dip in alcohol, open the nut, and immediately immerse in 95% ethanol solution.

Add the inoculum and quickly tighten the nut, ensuring sterile operation.

7. Dissolved Oxygen (DO) Setting

Dissolved oxygen control modes (Cascade settings):

None Mode: DO is controlled solely by airflow and fixed stirring speed.

Agit Mode:

When DO decreases, the stirring speed increases automatically.

Once the maximum stirring speed is reached, no further adjustments are made.

O₂ Mode:

Adjusts DO by modifying the oxygen-to-air ratio.

Agit/O₂ Mode:

Increases stirring speed first, and once the maximum is reached, oxygen flow increases.

Note: In Agit or Agit/O₂ mode, if the DO level is far below the setpoint, avoid setting an excessively high stirring speed to prevent high shear force and excessive foaming.