Continuous production of glucoamylase by immobilized growing cells ofAureobasidium pullulans

Abstract

Yeast-like cells ofAureobasidium pullulans were immobilized in Ca-alginate gel beads and employed for continuous production of glucoamylase in a fluidized-bed reactor (250 ml working volume). After an activation time of 48 h, to allow the “in situ” germination of the fungal blastospores, the reactor was operated continuously for over 150 h. A steady state enzyme concentration of 1.2–1.3 U ml−1 of glucoamylase activity and an enzyme volumetric productivity of ca. 130 U ml−1 h−1 were obtained at a medium flow rate of 26 ml h−1. Enzyme activity and volumetric productivity were influenced by fermentation conditions such as inoculum size and airflow rate.