title: Gluconate regulation of glucose catabolism in Pseudomonas fluorescens.
abstract: Induction of Entner-Doudoroff pathway enzymes in Pseudomonas fluorescens was investigated to study the role of gluconate as a possible inducer. Glucose oxidase-deficient mutants were isolated and characterized. One of these mutants, gox-7, was deficient in particulate glucose oxidase; another mutant, gox-17, was deficient in particulate glucose and gluconate oxidase activities. Gluconate, but not glucose, induced synthesis of gluconokinase and 6-phosphogluconate dehydratase in both mutants. High constitutive levels of 2-keto-3-deoxy-6-phosphogluconate aldolase were found when both mutants were grown on glucose. Growth of parent and both mutant strains on glycerol also resulted in high levels of Entner-Doudoroff pathway enzymes. It was concluded that glucose cannot serve as an inducer molecule for derepression of Entner-Doudoroff pathway enzymes in P. fluorescens. Evidence presented provides good support for gluconate being the true inducer of this pathway in P. fluorescens. A relationship is presented for explaining distribution of the Entner-Doudoroff pathway in certain groups of bacteria.
mesh_terms: D000429:Alcohol Oxidoreductases / Q000096:biosynthesis; D000446:Aldehyde-Lyases / Q000096:biosynthesis; D002474:Cell-Free System; D003470:Culture Media; D004790:Enzyme Induction; D005827:Genetics, Microbial; D005941:Glucokinase / Q000096:biosynthesis; D005942:Gluconates / Q000378:metabolism / Q000494:pharmacology*; D005947:Glucose / Q000378:metabolism*; D005949:Glucose Oxidase / Q000096:biosynthesis; D005954:Glucosephosphate Dehydrogenase / Q000096:biosynthesis; D005990:Glycerol / Q000378:metabolism; D006836:Hydro-Lyases / Q000096:biosynthesis; D009153:Mutagens; D009154:Mutation; D009604:Nitrosoguanidines; D010734:Phosphogluconate Dehydrogenase / Q000096:biosynthesis; D010770:Phosphotransferases / Q000096:biosynthesis; D011549:Pseudomonas / Q000378:metabolism*; D011551:Pseudomonas fluorescens / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism
chemical_list: D003470:Culture Media; D005942:Gluconates; D009153:Mutagens; D009604:Nitrosoguanidines; D000429:Alcohol Oxidoreductases; D010734:Phosphogluconate Dehydrogenase; D005954:Glucosephosphate Dehydrogenase; D005949:Glucose Oxidase; D010770:Phosphotransferases; D005941:Glucokinase; D000446:Aldehyde-Lyases; D006836:Hydro-Lyases; D005947:Glucose; D005990:Glycerol