Catabolism of D-glucose by Pseudomonas putida U occurs via extracellular transformation into D-gluconic acid and induction of a specific gluconate transport system.
Pseudomonas putida U does not degrade D-glucose through the glycolytic pathway but requires (i) its oxidation to D-gluconic acid by a peripherally located constitutive glucose dehydrogenase (insensitive to osmotic shock), (ii) accumulation of D-gluconic acid in the extracellular medium, and (iii) the induction of a specific energy-dependent transport system responsible for the uptake of D-gluconic acid. This uptake system showed maximal rates of transport at 30 degrees C in 50 mM potassium phosphate buffer, pH 7.0. Under these conditions the K(m) calculated for D-gluconic acid was 6.7 microM. Furthermore, a different transport system, specific for the uptake of glucose, was also identified. It is active and shows maximal uptake rates at 35 degrees C in 50 mM potassium phosphate buffer, pH 6.0, with a K(m) value of 8.3 microM.
Schleissner
Carmen
C
Departamento de Bioquímica y Biología Molecular, Facultad de Veterinaria, Universidad de León, 24007 León, Spain.
Reglero
Angel
A
Departamento de Bioquímica y Biología Molecular, Facultad de Veterinaria, Universidad de León, 24007 León, Spain.
Luengo
José M
JM
Departamento de Bioquímica y Biología Molecular, Facultad de Veterinaria, Universidad de León, 24007 León, Spain.
D000332:Aerobiosis; D001426:Bacterial Proteins / Q000378:metabolism; D001693:Biological Transport, Active; D004734:Energy Metabolism / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005110:Extracellular Space / Q000201:enzymology; D005942:Gluconates / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism*; D042843:Glucose 1-Dehydrogenase; D005948:Glucose Dehydrogenases / Q000378:metabolism; D007700:Kinetics; D009004:Monosaccharide Transport Proteins / Q000378:metabolism*; D009997:Osmotic Pressure; D016958:Pseudomonas putida / Q000187:drug effects / Q000378:metabolism*
D001426:Bacterial Proteins; D004791:Enzyme Inhibitors; D005942:Gluconates; D009004:Monosaccharide Transport Proteins; D005948:Glucose Dehydrogenases; D042843:Glucose 1-Dehydrogenase; D005947:Glucose; C030691:gluconic acid