Abstract:
:Physical damage of animal cells in suspension culture, due to stirring and sparging, is coupled with complex metabolic responses. Nylon microcapsules, therefore, were used as a physical model to study the mechanisms of damage in a stirred bioreactor and in a bubble column. Microcapsule breaskage folowed first-order kinetices in all experiments Entrainment of bubbles into the liquid phase in the stirred bioreactor gave more microcapsule breakage. In the bubble column, the bubble bursting zone at gas-liquid interface was primarily responsible for microcapsule breakage. The forces on the microcapsules were equivalent to an external pressure of approximately 4 x 10(4) N. m(-2), based on the critical microcapsule diameter for survival of 190 microm. A stable foam layer, however, was found to be effective in protecting microcapsules from damage. The microcapsule transport to the gas-liquid interface and entrainment into the foam phase was consistent with flotation by air bubbles. This result implies that additives and operation of bioreactors should be selected to minimize flotation of cells.
journal_name
Biotechnol Bioengjournal_title
Biotechnology and bioengineeringauthors
Lu GZ,Gray MR,Thompson BGdoi
10.1002/bit.260401018subject
Has Abstractpub_date
1992-12-05 00:00:00pages
1277-81issue
10eissn
0006-3592issn
1097-0290journal_volume
40pub_type
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