DEATH RATE IN A SMALL AIRLIFT-LOOP REACTOR OF VERO CELLS GROWN ON SOLID MICROCARRIERS AND IN MACROPOROUS MICROCARRIERS

The death rate of Vero cells grown on Cytodex-3 microcarriers was stud ied as a function of the gas flow rate in a small ah-lift loop reactor . The death rate may be described by first-order death-rate kinetics. The first-order death-rate constant as calculated from the decrease in viable cells, the increase in dead cells and the increase in LDH acti vity is linear proportional to the gas flow rate, with a specific hypo thetical killing volume in which all cells are killed of about 2 . 10( -3) m(3) liquid per m(3) of air bubbles. In addition, an experiment wa s conducted in the same air-lift reactor with Vero cells grown inside porous Asahi microcarriers. The specific hypothetical killing volume c alculated from this experiment has a value of 3 . 10(-4) m(3) liquid p er m(3) of air bubbles, which shows that the porous microcarriers were at least in part able to protect the cells against the detrimental hy drodynamic forces generated by the bubbles.