Microscopic visualization of insect cell-bubble interactions. II: The bubble film and bubble rupture.

In this paper, the second in the series, the use of a microscopic, high-speed video system to study the interactions of two suspended insect cells strains, Trichoplusia ni (TN-368) and Spodoptera frugiperda (SF-9), with rupturing bubbles is reported. Events such as the adsorption of cells onto the bubble film and the mechanism of bubble rupture were observed. On the basis of these observations and the experimental and theoretical work of other researchers on bubble rupture and cell death as a result of sparging, it is proposed that cells are killed by the rapid acceleration of the bubble film after rupture and the high levels of shear stress in the boundary layer flow associated with bubble jet formation.