42 Large-Scale Cell Culture
395
Results
Kloppinger et aI. (l990) cultured Sf-9 cells in a stirred tank with a 1.5-1
working volume connected to an external hollow fiber filtration module
(Fig. 5). Cell density in the tank increased from 1-2 x 10 5 to 2 X 10 6 cells/
ml over 3 days culture.
Comments
Refer to the Comments section in sub protocol 6.
Subprotocol 7
Air-Sparged Bioreactor Culture (Air-Lift Bioreactor Culture)
The air-lift bioreactor has some advantages over the stirred-tank
bioreactor. One of these advantages is that the air-lift bioreactor has no
shaft-bearing seals or a drive mechanism. This reduces the risk of microbial contamination of cell cultures. Oxygen is released as small bubbles
from an installed tube.
Materials
- Bioreactor with a low-shear axial-flow impeller
- Culture medium
Procedure
1. Harvest cells from a stock culture.
2. Place the cells into the tank.
3. Operate the culture system.
Results
Jem et aI. (l997) cultured insect cells in a 150-1 bioreactor in which a
normal ring sparger with holes of approximately 1.0 mm had been installed. The growth of the cells in the 150-1 bioreactor was comparable to
the growth of cells in a 5-1 bioreactor, but severe foaming problems and
shear damage to the cells because of the bursting of the air bubbles were
noticed in the larger tank. Cell damage occurs in particular during the
bursting of air bubbles at the suspension surface. The non-ionic surfactant Pluronic F-68 has protective effects against damage induced by the
bursting of the air bubbles. Pluronic F-68 and other polymers decrease
the speed at which air bubbles rise in the liquid. Additives that lower the
liquid-vapor interfacial tension of the culture medium also prevent the
adhesion of cells to the bubble surface (Chattopadhyaya et aI., 1995).
Equipment
Solutions
395
Results
Kloppinger et aI. (l990) cultured Sf-9 cells in a stirred tank with a 1.5-1
working volume connected to an external hollow fiber filtration module
(Fig. 5). Cell density in the tank increased from 1-2 x 10 5 to 2 X 10 6 cells/
ml over 3 days culture.
Comments
Refer to the Comments section in sub protocol 6.
Subprotocol 7
Air-Sparged Bioreactor Culture (Air-Lift Bioreactor Culture)
The air-lift bioreactor has some advantages over the stirred-tank
bioreactor. One of these advantages is that the air-lift bioreactor has no
shaft-bearing seals or a drive mechanism. This reduces the risk of microbial contamination of cell cultures. Oxygen is released as small bubbles
from an installed tube.
Materials
- Bioreactor with a low-shear axial-flow impeller
- Culture medium
Procedure
1. Harvest cells from a stock culture.
2. Place the cells into the tank.
3. Operate the culture system.
Results
Jem et aI. (l997) cultured insect cells in a 150-1 bioreactor in which a
normal ring sparger with holes of approximately 1.0 mm had been installed. The growth of the cells in the 150-1 bioreactor was comparable to
the growth of cells in a 5-1 bioreactor, but severe foaming problems and
shear damage to the cells because of the bursting of the air bubbles were
noticed in the larger tank. Cell damage occurs in particular during the
bursting of air bubbles at the suspension surface. The non-ionic surfactant Pluronic F-68 has protective effects against damage induced by the
bursting of the air bubbles. Pluronic F-68 and other polymers decrease
the speed at which air bubbles rise in the liquid. Additives that lower the
liquid-vapor interfacial tension of the culture medium also prevent the
adhesion of cells to the bubble surface (Chattopadhyaya et aI., 1995).
Equipment
Solutions