title: rpoS gene expression in carbon-starved cultures of the Polyhydroxyalkanoate-accumulating species Pseudomonas oleovorans.
abstract: The expression of the rpoS gene during PHA depolymerization was monitored in Pseudomonas oleovorans GPo1 and its mutant defective in PHA degradation by analyzing the tolerance to oxidative and thermal stresses and the RpoS intracellular content. An increase in the tolerance to H2O2 and heat shock was observed coincidentally with PHA degradation. Western blotting experiments performed in carbon-starved cultures showed that the RpoS levels were higher in the wild type than in the mutant strain. Complementation of the phaZ mutation restores the wild-type RpoS levels. These results suggest a probable association between PHA depolymerization and the stress tolerance phenotype controlled by RpoS.
authors.affiliation: Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pabellón 2, 1428, Buenos Aires, Argentina.
authors.forename: Jimena A
authors.initials: JA
authors.lastname: Ruiz
authors.forename: Nancy I
authors.initials: NI
authors.lastname: López
authors.forename: Beatriz S
authors.initials: BS
authors.lastname: Méndez
mesh_terms: D001426:Bacterial Proteins / Q000032:analysis / Q000235:genetics*; D015153:Blotting, Western; D002244:Carbon / Q000378:metabolism; D002265:Carboxylic Ester Hydrolases / Q000235:genetics / Q000378:metabolism; D015169:Colony Count, Microbial; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D005816:Genetic Complementation Test; D018869:Heat-Shock Response / Q000235:genetics; D006861:Hydrogen Peroxide / Q000494:pharmacology; D016254:Mutagenesis, Insertional; D009154:Mutation; D016877:Oxidants / Q000494:pharmacology; D018384:Oxidative Stress / Q000235:genetics; D011091:Polyesters / Q000378:metabolism*; D044204:Pseudomonas oleovorans / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D012808:Sigma Factor / Q000032:analysis / Q000235:genetics*; D013696:Temperature
chemical_list: D001426:Bacterial Proteins; D016877:Oxidants; D011091:Polyesters; D012808:Sigma Factor; C069567:sigma factor KatF protein, Bacteria; D002244:Carbon; D006861:Hydrogen Peroxide; D002265:Carboxylic Ester Hydrolases; C077226:poly(3-hydroxyalkanoic acid) depolymerase