The uptake of 2-ketogluconate by Pseudomonas putida |
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Authors: | G De Torrontegui R Díaz J L Cánovas |
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Institution: | (1) Instituto der Biología Celular, C.S.I.C., Velázquez, 144, Madrid-6, Spain;(2) Present address: Department of Genetics, University of Leicester, University Road, LE1 7RH Leicester, England |
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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 K
min 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.Abbreviations CCCP
carbonyl-cyanide-m-chlorophenyl-hydrazone
- cpm
radioactivity counts per minute
- GGU
glucose-gluconate uptake
- PFU
plaque forming units
- U.V.
ultraviolet
Dedicated to Prof. Roger Y. Stainer on the occasion of his 60th birthday |
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Keywords: | 2-Ketogluconate uptake Bacterial transport Transport mutants Pseudomonas putida |
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