1991 Volume 17 Issue 4 Pages 873-881
The determination of gas-liquid and liquid-solid oxygen transfer coefficients, kLa and kS, from measurement of the steady-state dissolved oxygen concentration, CO, S, was examined by using oxidation of glucose with air catalyzed by glucose oxidase, GO. Free GO and immobilized GO gel beads were employed respectively for determination of kLa and kS. The contactors used were a small-scale aerated stirred cell and a bubble column with draft tube. The kinetic parameters for free GO were almost identical to those in the literature. The difference in the values of kLa between the enzymatic and physical methods was found to be attributable to foaming in the enzyme reaction medium. The determination of kLa could be applied to the cultivation broths. On the other hand, the rate equation for the immobilized GO gel beads was described in the same form as in the case of the free enzyme except that the utilization efficiency of GO loaded for immobilization, α, was introduced into the equation. The kLa values in the presence of gel beads were practically equal to those for the gas-liquid system. The values of kS calculated from CO, S, kLa, α, the kinetic parameters and the GO gel. beads loading agreed satisfactorily with those obtained in physical dissolution.