Sorption characteristic in biological material systems

In supplying oxygen to the aerobic microorganisms it must be taken into consideration that the cells may affect the oxygen transfer rates from air to the medium in three ways a) by their own breathing activity, b) in their property as solid particles and c) by changing the physical properties of the medium. These three possible effects were investigated in [242] with baker s yeast as biomaterial in a stirred tank 

The provision of a mammal or plant cell culture with aerobic oxygen is as a rule made more difficult by the fact, that, on the one hand, these cells can tolerate hardly any mechanical shear stress (see Section 1.3.5) and, on the other hand, the G/L interface has a cell-damaging effect (damaging of the fold-structure of the proteins). 

For this reason a so-called bubble-free provision of oxygen is carried out when the occasion arises, for which there are two possibilities  

1) The oxygen is fed under pressure though silicone helical coil dipped into the liquid. The gas diffuses through the wall of the tubing to its surface, where it 

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