Article

The role of oxygen in the regulation of glucose metabolism, transport and the tricarboxylic acid cycle in Pseudomonas aeruginosa.

Journal of general microbiology 02/1982; 128(1):49-59. DOI: 10.1099/00221287-128-1-49
Source: PubMed

ABSTRACT The effect of dissolved oxygen concentration on the metabolism of glucose in Pseudomonas aeruginosa was studied with chemostat cultures using both single-step and gradual transitions from either ammonium or glucose limitation to oxygen limitation and studying transient and steady states. The pathway of glucose metabolism was regulated by the availability of oxygen. The organism responded to oxygen limitation by adjusting its metabolism of glucose from the extracellular direct oxidative pathway, which produces gluconate and 2-oxogluconate, to the intracellular phosphorylative route. This change was a consequence of decreased activities of glucose dehydrogenase and gluconate dehydrogenase and of the transport systems for gluconate and 2-oxogluconate, and an increased activity of glucose transport, while relatively high activities of hexokinase and glucose-6-phosphate dehydrogenase were maintained. Citrate synthase, isocitrate dehydrogenase and malate dehydrogenase activities responded to changes in dissolved oxygen concentration rather than to changes in the glucose or ammonium concentrations. The effect of oxygen limitation on the oxo-acid dehydrogenases and aconitase was probably due, wholly or in part, to repression by glucose consequent upon the increase in residual glucose concentration. Succinate dehydrogenase was repressed by an increase in ammonium concentration under an oxygen limitation.

0 Bookmarks
 · 
175 Views
  • Source
    Microbiology 09/1983; 129(9):2885-2891. · 2.84 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The optimum conditions for D-glucose dehydrogenase production from Bacil- lus thuringiensis M15 were investigated in flask cultures. Various concentrations of car- bon and nitrogen sources including the culture conditions were studied for the enzyme production. The highest enzyme yield was obtained from 100 ml of cultivation medium containing (w/v) 0.12% trehalose, 0.25% ammonium chloride, 0.1% KH2PO4, 0.1% K2HPO4, 0.01% MgSO4·7H2O and 0.02% yeast extract, pH 6.5. The suitable culture con- dition at 30 oC was shaking speed at 100 rev min-1 for 2 days. The highest enzyme activ- ity and specific activity in flask culture were 3 mU ml-1 and 6 mU mg-1, respectively. At the final optimization step, the enzyme total unit was higher than the beginning step about 4 times. The maximum enzyme activity in a jar fermentor which obtained from 21 h culti- vation was 1.27 mU ml-1.
    Annals of Microbiology 01/2004; 54:87-93. · 1.04 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Microbiological changes were studied in minced beef and minced dark, firm, dry (DFD) pork stored under different atmospheres (100% in carbon dioxide, nitrogen or air) at 3°C. The storage life (time for 100-fold increase in TVC) of samples flushed with carbon dioxide was increased by c. 3–4 days. Pseudomonads were the dominant organisms in samples stored in air, and lactic acid bacteria and Brochothrix thermosphacta in those stored under carbon dioxide. There was an alkaline drift in all samples, but at different rates (air > nitrogen > carbon dioxide). The rate of glucose assimilation in normal and DFD beef was slower in the samples stored under carbon dioxide than those under nitrogen or air. Lactate, gluconate, acetic acid, ethanol and diacetyl occurred in normal and DFD beef regardless of the storage atmospheres.
    International Journal of Food Science & Technology 06/2007; 25(4):389 - 398. · 1.35 Impact Factor

Preview

Download
0 Downloads
Available from