EFFECT OF CARBON SOURCES ON FORMATION OF α-AMYLASE AND GLUCOAMYLASE BY CLOSTRIDIUM ACETOBUTYLICUM

Abstract

As determined by enzyme levels and by differential rate of enzyme formation, the synthesis of α-amylase and glucoamylase by Clostridium acetobutylicum is under separate regulatory systems. Induction of α-amylase occurs when starch is the carbon source while induction of glucoamylase accompanies growth with glucose. Minimal production of both enzymes is associated with growth on fructose, and intermediate levels result from growth with maltose. While both α-amylase and glucoamylase are elaborated into the culture fluid during the logarithmic growth phase, 41-44% of total amylase and 22-33% of total glucoamylase remain associated with the bacterial cells. Studies involving cell fractionation, cell washing, and pH-dependent adsorptions indicate that cell-associated α-amylase and glucoamylase are localized primarily with the surface of the cells and only to a small extent with the intracellular region.