title: Hydrogen peroxide stress provokes a metabolic reprogramming in Pseudomonas fluorescens: enhanced production of pyruvate.
abstract: Pseudomonas fluorescens invoked a metabolic reconfiguration that resulted in enhanced production of pyruvate under the challenge of hydrogen peroxide (H₂O₂). Although this stress led to a sharp reduction in the activities of numerous tricarboxylic acid (TCA) cycle enzymes, there was a marked increase in the activities of catalase and various NADPH-generating enzymes to counter the oxidative burden. The upregulation of phosphoenolpyruvate synthase (PEPS) and pyruvate kinase (PK) coupled with the reduction of pyruvate dehydrogenase (PDH) in the H₂O₂-challenged cells appear to be important contributors to the elevated levels of pyruvate found in these bacteria. Increased pyruvate synthesis was evident in the presence of a variety of carbon sources including d-glucose. Intact cells rapidly consumed d-glucose with the concomitant formation of this monocarboxylic acid. At least a 12-fold increase in pyruvate production within 1h was observed in the stressed cells. These findings may be exploited in the development of technologies aimed at the conversion of carbohydrates into pyruvate.
authors.affiliation: Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario P3E 2C6, Canada.
authors.forename: Adam
authors.initials: A
authors.lastname: Bignucolo
authors.forename: Varun P
authors.initials: VP
authors.lastname: Appanna
authors.forename: Sean C
authors.initials: SC
authors.lastname: Thomas
authors.forename: Christopher
authors.initials: C
authors.lastname: Auger
authors.forename: Sungwon
authors.initials: S
authors.lastname: Han
authors.forename: Abdelwahab
authors.initials: A
authors.lastname: Omri
authors.forename: Vasu D
authors.initials: VD
authors.lastname: Appanna
mesh_terms: D006861:Hydrogen Peroxide / Q000494:pharmacology*; D053858:Metabolic Networks and Pathways; D018384:Oxidative Stress / Q000187:drug effects*; D017866:Phosphotransferases (Paired Acceptors) / Q000378:metabolism; D011551:Pseudomonas fluorescens / Q000187:drug effects* / Q000378:metabolism; D011770:Pyruvate Kinase / Q000378:metabolism; D011773:Pyruvates / Q000378:metabolism*; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D011773:Pyruvates; D006861:Hydrogen Peroxide; D011770:Pyruvate Kinase; D017866:Phosphotransferases (Paired Acceptors); C022509:pyruvate, water dikinase
keywords: 6-phosphogluconate dehydrogenase; 6PGDH; BN-PAGE; BSA; Bioconversion; CFE; ETC; FUM; G6PDH; GDH; HPLC; ICDH; KGDH; Metabolic reconfiguration; NADPH-generating enzymes; PDH; PEPS; PK; Phosphoenolpyruvate synthase; Pyruvate production; TCA; alpha-ketoglutarate dehydrogenase; blue native polyacrylamide gel electrophoresis; bovine serum albumin; cell free extract; electron transport chain; fumarase; glucose-6-phosphate dehydrogenase; glutamate dehydrogenase; high performance liquid chromatography; isocitrate dehydrogenase; phosphoenolpyruvate synthase; pyruvate dehydrogenase; pyruvate kinase; tricarboxylic acid