A KINETIC-MODEL FOR THE PECTIN HYDROLYSIS USING AN ENDO-ACTING PECTINASE FROM RHIZOPUS

Enzyme kinetics of pectin hydrolysis reaction catalysed by an endo-pol ygalacturonase from Rhizopus have been analysed experimentally in a st irred batch reactor at pH = 4.5 and T = 34 degrees C using a sodium sa lt of polygalacturonic acid as substrate. The reaction products, consi sting of oligomers of galitcturonic acid, were classified in four clas ses of oligomeric fractions employing three hollow fibre ultrafiltrati on units characterised by different molecular weight cut-off (MW(co)). On the basis of the time-concentration data, a kinetic model of the r eacting system has been proposed in terms of a series-side reaction pa ttern. Identification of kinetic parameters was carried out by a non-l inear regression optimization procedure based on the Powell's algorith m of conjugated directions. Finally, the kinetic model was used to pre dict the best reactor configuration able to control the product distri bution for a given enzyme/substrate concentration ratio.