Transport of L-glucose by Rhodotorula glutinis.

Abstract The kinetics of l -glucose transport by Rhodotorula glutinis were studied over a 720-fold range of sugar concentrations. Analysis of the saturation isotherm revealed the presence of a one-carrier system for l -glucose in the plasma membrane of Rhodotorula glutinis . This carrier exhibited a k m of 3.7 ± 0.3 mM. d -Ribose was found to be a competitive inhibitor with a K i of 19 ± 1 mM. The results suggest that l -glucose is transported by the high- K m , d -ribose carrier. l -Glucose was transported against a concentration gradient and the transport was inhibited by the proton conductor 2,4-dinitrophenol.