Figure 15.5 Schematic drawing of the
bubble burst process. Arrows on the
left connecting b and e show the origin
of the liquid present in the jet. Shaded
areas represent the regions of high
shear.
rupture of the film. Earlier Tramper et al. (1988) measured the effect of film rupture by
repeated blowing of a bubble from a pipette and found that about 6% of the cells were
killed upon rupture. Cherry and Hulle (1992) using a metal wire loop have also studied
the effect of rupture of a single film. After spontaneous rupture they found that about
20% of the cells were killed. The cell death upon rupture found by Tramper et al. (1988)
and Cherry and Hulle (1992) is thus significantly less than the value found by Trinh et al.
(1994). This may be explained by the fact that protective additives were present in the
media used by Cherry and Hulle (1992) (3% FBS) and Tramper et al. (10% FBS with
0.1% methyl-cellulose).
Multiphase bioreactor design 474