DESIGN OF A BUBBLE-SWARM BIOREACTOR FOR ANIMAL-CELL CULTURE

A stationary bubble-swarm has been used to aerate a mammalian cell cul ture bioreactor with an extremely low gas flow rate. Prolonging the re sidence time of the gas bubbles within the medium improved the efficie ncy of the gas transfer into the liquid phase and suppressed foam form ation. An appropriate field of speed gradients prevented the bubbles f rom rising to the surface. This aeration method achieves an almost 90% transfer of oxygen supplied by the bubbles. Consequently, it is able to supply cells with oxygen even at high cell densities, while spargin g with a gas flow of only 0.22 10(-3) -1.45.10(-3) vvm (30-200 ml/h). The reactor design, the oxygen transfer rates and the high efficiency of the system are presented. Two repeated batch cultures of a rat-mous e hybridoma cell line are compared with a surface-aerated spinner cult ure. The used cell culture medium was serum-free, either with or witho ut BSA and did not contain surfactants or other cell protecting agents . One batch is discussed in detail for oxygen supply, amino acid consu mption and specific antibody production.