METABOLISM OF CARBOHYDRATES BY PSEUDOMONAS SACCHAROPHILA II

Abstract

Fructose-adapted mutant strains of P. saccharophila contain a "mannose isomerase" which interconverts fructose and mannose. Fructose is phosphorylated with adenosine triphosphate (ATP) to fructose-6-phosphate. The kinase is specific and distinct from the kinase (s) involved in the phosphorylation of glucose and mannose. Fructose-1-phosphate is not the initial product of phosphorylation and neither adenosine diphosphate (ADP) nor glucose have a significant inhibitory effect on the reaction. Mannose can be phosphorylated slowly by fructose-adapted strains. The wild-type strain grown on maltose, which contains neither mannose isomerase nor fructokinase, phosphorylates mannose to mannose-6-phosphate. Both glucose 6-phosphate and fructose accumulate in intact cells of a fructose-adapted culture during oxidation of fructose.