Asymmetric Response of Carbon Metabolism at High and Low Salt Stress in Vibrio sp. DSM14379

• Published in: Microbial ecology 2011-07, Vol.62 (1), p.198-204
• Main Authors: Danevčič, Tjaša, Stopar, David
• Format: Article
• Language: English
• Subjects: ATP; Bacteria; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Biochemical pathways; Biological and medical sciences; Biomedical and Life Sciences; Brackish; Carbon; Carbon - metabolism; Carrying capacity; Cell growth; Dehydrogenase; Dehydrogenases; Ecology; Estuarine environments; Fundamental and applied biological sciences. Psychology; Geoecology/Natural Processes; Life Sciences; Metabolic Networks and Pathways; Microbial Ecology; Microbiology; Nature Conservation; Peptones; Phosphates; PHYSIOLOGY AND BIOTECHNOLOGY; Respiration; Salinity; Salts; Seawater - microbiology; Sodium chloride; Sodium Chloride - metabolism; Steepest descent method; Survival; Table salt; Vibrio; Vibrio - genetics; Vibrio - isolation & purification; Vibrio - metabolism; Water Quality/Water Pollution; Yeasts
• ISSN: 0095-3628; 1432-184X
• DOI: 10.1007/s00248-011-9870-3

Energy redistribution between growth and maintenance in salt-stressed cells is especially important for bacteria living in estuarine environments. In this study, Gram-negative bacterium Vibrio sp. DSM 14379, isolated from the estuarine waters of the northern Adriatic Sea, was grown aerobically in a peptone-yeast extract medium with different salt concentrations (ranging from 0.3% to 10% (w/v) NaCl). Carbon flux through the central metabolic pathways was determined at low and high salt concentrations. At low salt concentrations, total endogenous respiration, dehydrogenase activity, and net intracellular adenosine triphosphate (ATP) concentration significantly increased, the phosphofructokinase and pyruvate kinase activity decreased, whereas glucose-6-phosphate dehydrogenase activity remained unchanged. The carrying capacity of bacterial culture decreased dramatically, indicating a severe metabolic imbalance at low salt concentrations. At high salt concentrations, carrying capacity decreased gradually. There was a large increase in glucose-6-phosphate dehydrogenase activity, which correlated with a 10-fold increase in concentration of osmoprotectant L-proline. There was no significant change of net intracellular ATP concentration, phosphofructokinase, or pyruvate kinase activity. The results indicate that Vibrio sp. DSM 14379 central metabolic pathways respond to low and high salt concentrations asymmetrically; cells are better adapted to high salt concentrations. In addition, cells in the stationary phase can tolerate induced salt stress without a significant change in dehydrogenase activity or endogenous respiration for at least 1 h, but need to alter their macromolecular composition and carbon flux distribution for long-term survival.