Performance of continuous enzyme reactor system

Abstract

As a basic research for the continuous glucose isomerization reactor kinetics, batch kinetics have been studied primarily. Glucose-isomerase in the form of whole-cell-enzyme has been prepared using a strain of $\mbox{\underline{Streptomyces}$ $\mbox{\underline{phaeochromogenes}$. The stability of the enzyme during storage in 0.05M phosphate buffer solution (PH 7.02) at 5℃ was investigated. The activity decay constant of the enzyme was found to be 0.0017 $hr^{-1}$ under the given storage conditions. It was proved that the glucose isomerization reaction follows the Reversible One Substrate Enzyme Reaction Kinetics. The Michaelis-Menten constants were found to be 0.238M for forward reaction and 0.490M for reverse reaction. The maximum reaction rates of forward and reverse reaction were 8.75 and 13.2m mole/ 1/min respectively when the enzyme loading was 2,760IU per liter of reaction solution. The equilibrium constant of the reaction was found to be 1.36 and the reaction conditions used were 70±0.5℃ and PH 6.8±0.2 throughout the work. The kinetic constants were compared with those of other workers$^{20,22}$ and the specific activity of the enzyme were also compared. For the purpose of comparing the data on the specific activity, we have adopted the International Unit system. The specific activity of this enzyme, i. e. 0.23 unit/mg of dey cell weight, was found to be good and it was generally accepted that the affinity of this enzyme to substrate is greater than that to product at a relatively high reaction temperature, i. e. 60℃ or more. Using the kinetic model it was possible to estimate the reaction time required to achieve 99.9% of equilibrium conversion for each reaction under arbitrary substrate concentration and enzyme loading. The kinetic property of the model was compared with the general Michaelis-Menten type equation. Based upon the batch kinetics, a continuous tubular-type reactor was designed and a mathematical model for the continuous enzyme reactor was...