title: The uptake of 2-ketogluconate by Pseudomonas putida.
abstract: The uptake of 2-ketogluconate is inducible in Pseudomonas putida: 2-ketogluconate, glucose, gluconate, glycerol and glycerate were each good nutritional inducers of this ability. 2-Ketogluconate uptake obeyed saturation kinetics (apparent Km in 2-ketogluconate-grown cells was 0.4 mM). 2-Ketogluconate was transported against a concentration gradient, apparently in an unchanged state, and the process required metabolic energy, all of which indicate an active transport system. A number of independently isolated mutants with deranged activity of a common glucose-gluconate uptake system were found to be also defective in 2-ketogluconate transport. Strains unable to transport 2-ketogluconate which grew readily on glucose and gluconate were also isolated. These results suggest that 2-ketogluconate transport is governed by at least two genetic elements: one which is also required to take up glucose and gluconate and another which appears to be specific for 2-ketogluconate transport. Similarly, glucose and gluconate transport appears to require at least one factor which is not necessary for 2-ketogluconate transport, as suggested by the lack of induction of the common glucose-gluconate uptake system by glycerol and glycerate, substrates which are good inducers of 2-ketogluconate uptake.
mesh_terms: D001693:Biological Transport, Active; D005942:Gluconates / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism; D007651:Keto Acids / Q000378:metabolism; D009154:Mutation; D011549:Pseudomonas / Q000378:metabolism*
chemical_list: D005942:Gluconates; D007651:Keto Acids; C008229:2-ketogluconate; D005947:Glucose