Kinetics of Sucrose Hydrolysis by Immobilized Recombinant Pichia pastoris Cells in a Batch reactors

Abstract

Sucrose hydrolysis was carried out in a constant-volume batch reactor, using recombinant Pichia pastoris BfrA4X whole cells expressing Thermotoga maritima invertase, entrapped in calcium alginate beads. The kinetics of the enzymatic hydrolysis of sucrose by the biocatalyst was examined at substrate concentrations ranging between 0.03 M and 2.04 M. The reaction rate increases until 0.31 M after which the reaction velocity was constant until 1.16 M, above this concentration, the reaction rate decreases with increasing sucrose concentration. The experimental data obtained with two weight of the biocatalyst were incorporated into two kinetic models to predict the reaction time needed for sucrose hydrolysis. One model was applied for sucrose concentrations bellow 1.16 M while a second one could be used at inhibitory range between 1.46 and 2.04 M with a k value as function of initial sucrose concentration and biocatalyst weight.