TY - JOUR
T1 - A diffusion model and optimal cell loading for immobilized cell biocatalysts
AU - Zhao, Yujun
AU - Delancey, George B.
PY - 2000/9/20
Y1 - 2000/9/20
N2 - A diffusion model based on the random pore model is derived for immobilized cell biocatalysts and verified with 19 sets experimental diffusion data. The predicted effective diffusivity relative to that for the support matrix reflects a quadratic dependence on the cell loading and contains a single parameter that depends on the intracellular diffusivity and the chemical partitioning coefficient. The model is used to predict optimal cell loadings that maximize the total reaction rate in an immobilized cell biocatalyst. A rule of thumb based on the diffusion model is obtained to the effect that the cell loading should beat least 1/3 for single reactions regardless of the kinetics and diffusional resistances. A means of calculating improved lower bounds is provided for cases where the cellular diffusional resistance is known but the kinetics are not. The optimal cell loadings for reversible first-order and for Michaelis-Menten kinetics are presented and demonstrated to be within the range of conditions of practical interest. (C) 2000 John Wiley and Sons, Inc.
AB - A diffusion model based on the random pore model is derived for immobilized cell biocatalysts and verified with 19 sets experimental diffusion data. The predicted effective diffusivity relative to that for the support matrix reflects a quadratic dependence on the cell loading and contains a single parameter that depends on the intracellular diffusivity and the chemical partitioning coefficient. The model is used to predict optimal cell loadings that maximize the total reaction rate in an immobilized cell biocatalyst. A rule of thumb based on the diffusion model is obtained to the effect that the cell loading should beat least 1/3 for single reactions regardless of the kinetics and diffusional resistances. A means of calculating improved lower bounds is provided for cases where the cellular diffusional resistance is known but the kinetics are not. The optimal cell loadings for reversible first-order and for Michaelis-Menten kinetics are presented and demonstrated to be within the range of conditions of practical interest. (C) 2000 John Wiley and Sons, Inc.
KW - Biocatalyst capacity
KW - Diffusion model
KW - Effective diffusivity
KW - Immobilized cells
KW - Optimal cell loading
KW - Reaction rate
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U2 - 10.1002/1097-0290(20000920)69:6<639::AID-BIT8>3.0.CO;2-V
DO - 10.1002/1097-0290(20000920)69:6<639::AID-BIT8>3.0.CO;2-V
M3 - Article
C2 - 10918139
AN - SCOPUS:0034692621
SN - 0006-3592
VL - 69
SP - 639
EP - 647
JO - Biotechnology and Bioengineering
JF - Biotechnology and Bioengineering
IS - 6
ER -