Succinate-mediated catabolite repression control on the production of glycine betaine catabolic enzymes in Pseudomonas aeruginosa PAO1 under low and elevated salinities.
Glycine betaine (GB) and its immediate precursors choline and carnitine, dimethylsulfonioacetate, dimethylsulfoniopropionate, ectoine and proline were effective osmoprotectants for Pseudomonas aeruginosa, but pipecolate, trehalose and sucrose had no osmoprotective effect. GB was accumulated stably or transiently when succinate or glucose, respectively, was used as a carbon and energy source. The catabolite repression mediated by succinate occurred at both low and high salinities, and it did not involve the global regulators Vfr and Crc. A proteomic analysis showed that at least 21 proteins were induced when GB was used as a carbon and energy source, and provided evidence that succinate repressed the synthesis of all these proteins. Many of the proteins induced by GB (sarcosine oxidase, serine hydroxymethyltransferase and serine dehydratase) are involved in GB catabolism. In addition, GB uptake was stimulated at high medium osmolalities but it was insensitive to catabolite repression by succinate. Despite its ability to inhibit betaine catabolism, succinate did not allow any better growth of P. aeruginosa cells under hyperosmotic constraint. Conversely, as observed for cells supplied with glucose, a transient accumulation of GB was sufficient to provide a significant cell osmoprotection.
Diab
Farès
F
Departement Osmorégulation chez les Bactéries, UMR-CNRS 6026, Université de Rennes 1, Campus de Beaulieu, Av. du Général Leclerc, 35042 Rennes, France.
Bernard
Théophile
T
Departement Osmorégulation chez les Bactéries, UMR-CNRS 6026, Université de Rennes 1, Campus de Beaulieu, Av. du Général Leclerc, 35042 Rennes, France.
Bazire
Alexis
A
Laboratoire de Biotechnologie et Chimie Marines, EA 3884, Université de Bretagne Sud, Lorient, France.
Haras
Dominique
D
Laboratoire de Biotechnologie et Chimie Marines, EA 3884, Université de Bretagne Sud, Lorient, France.
Blanco
Carlos
C
Departement Osmorégulation chez les Bactéries, UMR-CNRS 6026, Université de Rennes 1, Campus de Beaulieu, Av. du Général Leclerc, 35042 Rennes, France.
Jebbar
Mohamed
M
Departement Osmorégulation chez les Bactéries, UMR-CNRS 6026, Université de Rennes 1, Campus de Beaulieu, Av. du Général Leclerc, 35042 Rennes, France.
D000222:Adaptation, Physiological; D001426:Bacterial Proteins / Q000032:analysis / Q000302:isolation & purification; D001622:Betaine / Q000378:metabolism*; D015180:Electrophoresis, Gel, Two-Dimensional; D004794:Enzyme Repression; D004798:Enzymes / Q000096:biosynthesis*; D015964:Gene Expression Regulation, Bacterial; D005947:Glucose / Q000378:metabolism; D009994:Osmolar Concentration; D020543:Proteome / Q000032:analysis / Q000302:isolation & purification; D011550:Pseudomonas aeruginosa / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D012965:Sodium Chloride / Q000494:pharmacology; D019802:Succinic Acid / Q000378:metabolism*
D001426:Bacterial Proteins; D004798:Enzymes; D020543:Proteome; D001622:Betaine; D012965:Sodium Chloride; D019802:Succinic Acid; D005947:Glucose