BUBBLE-FREE OXYGENATION BY MEANS OF HYDROPHOBIC POROUS MEMBRANES

Bubble-free aeration is applied in animal cell culture processes for o xygenation to avoid shear stress and foaming associated with direct sp arging into the culture. Oxygen mass transfer across PTFE-membranes wa s determined in three different reactor systems that may be applied to animal cell cultures. Oxygen was supplied on the aeration side of the membrane by air- or oxygen-saturated aqueous liquids, or directly usi ng air or pure oxygen, By using liquids, the bubble-free aeration may be combined with an ammonia removal system, using the same membranes a nd described in an earlier publication. By providing oxygen directly i n gaseous form, the use of PTFE-tubing enabled a reduction in the mass transfer surface by a factor of two or three, in comparison to aerati on with silicone tubing. PTFE-membranes were successfully used to cont rol dissolved oxygen concentrations in cultures of different animal ce ll lines.