Glucoamylase Produced by Rhizopus and by a Recombinant Yeast Containing the Rhizopus Glucoamylase Gene

Abstract

Recombinant Rhizopus glucoamylase produced by a yeast containing the Rhizopus glucoamylase gene was purified, characterized, and compared with native Rhizopus glucoamylase. The recombinant glucoamylase was similar to Glue 1, one of three forms of Rhizopus native glucoamylase, but it degraded raw starch more efficiently than the native glucoamylase. Recombinant glucoamylase and Glue 1 adsorbed to gelatinized soluble starch as well as raw starch. These findings suggested that Rhizopus glucoamylase consists of two domains; one for causing adsorption to the starch and the other for catalyzing degradation of the starch molecule.