Kinetic Study on Hydrolysis of Various Pectins by Aspergillus niger Polygalacturonase

Abstract

Hydrolysis of pectins from various sources by a polygalacturonase (PG) enzyme was studied from a kinetic point of view. Pectin substrates – which are commercially not available – were extracted from sugar beet pulp, apple, red currant and black currant. Strong product inhibition was found in each pectin preparations that could be described by a competitive mechanism. The kinetic parameters (Michaelis-Menten constants, maximal reaction rates and inhibition constants) were determined and compared. Differences in the parameters imply distinctions in structure of the pectins studied.