ENZYMATIC UTILIZATION OF GLUCOSE BY A BASIDIOMYCETE

Abstract

Meloche, H. P., Jr . (Northern Regional Research Laboratory, Peoria, Ill.). Enzymatic utilization of glucose by a basidiomycete. J. Bacteriol. 83: 766–774. 1962.—Cell-free extracts of acetone-dried Lactarius torminosus NRRL 2900 were prepared. These extracts contained hexokinase. They also contained triphosphopyridine nucleotide (TPN)-specific glucose-6-phosphate dehydrogenase and catalyzed the reduction of TPN in the presence of d -fructose-6-phosphate, 6-phospho- d -gluconic acid (6PG), and d -ribose-5-phosphate (R5P). Aged preparations oxidized d -glucose-6-phosphate (G6P) to 6PG, whereas fresh preparations oxidized G6P to a pentose with the uptake of 1 μmole of O 2 and the evolution of 1 μmole of CO 2 per μmole of G6P. Evidence for the action of transketolase in the metabolism of R5P by cell-free extracts was obtained. Cell-free preparations lacked hexosediphosphate enzymes. Triosephosphate isomerase and F6P kinase could not be demonstrated; however, aldolase activity was present. Evidence is presented for the conversion of d -glyceraldehyde-3-phosphate to pyruvate. In addition, phosphohexoisomerase was demonstrated. It appears that a hexosemonophosphate pathway operates in L. torminosus extracts and may be the major mechanism of glucose dissimilation in this organism.