Fermentative Phosphorylation of Galactose by Yeast

Abstract

A reaction system for galactose 1-phosphate (Gal l-P) production was established in the presence of a high concentration of inorganic phosphate ion in which yeast fermentation was conjugated with the galactokinase activity.
Dried cells of Torulopsis candida IFO 0768, grown on lactose, were used as the galacto-kinase source. The Gal 1-P formed by fermenting the conjugated system of 100mg per ml of T. candida with 50mg per ml of baker's yeast was 45mM during 4 hr of incubation. An addition of 5 or 10mM of adenosine derivatives accelerated Gal 1-P formation more than 1.5 times. The formation of Gal 1-P in this reaction system was significantly affected by the amount of fructose 1, 6-bisphosphate (FBP) accumulated in the reaction medium.