Iron-Dependent Production of Hydroxamate by Sodium-Dependent Azotobacter chroococcum
AUTOR(ES)
Page, William J.
RESUMO
The sodium-dependent strain 184 of Azotobacter chroococcum was unable to grow significantly in iron-limited medium, but did produce iron-repressible outer membrane proteins. Siderophores were not produced under these conditions. Citric acid was excreted, but not in response to iron limitation. This strain, however, was able to grow in insoluble mineral iron sources, and under these conditions the cells produced a hydroxamate. Growth on minerals and hydroxamate production was dependent on a low level of freely exchangeable iron. Optimal hydroxamate production was observed with 0.75 μM ferric citrate, and hydroxamate production was repressed by >5 μM iron. Despite this iron requirement, hyroxamate was only formed during internal iron limitation of the cells. Iron-containing cells were able to grow in iron-limited medium but only produced hydroxamate when their iron-per-cellular-protein content was low. These results, the spectral changes observed upon Fe3+ addition, and iron-uptake coincident with hydroxamate production suggested that the hydroxamate was a siderophore.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=203886Documentos Relacionados
- Sodium-Dependent Growth of Azotobacter chroococcum
- Sodium-Dependent Azotobacter chroococcum Strains Are Aeroadaptive, Microaerophilic, Nitrogen-Fixing Bacteria
- Sodium-dependent magnesium uptake by ferret red cells.
- Regulation of sodium-dependent phosphate transport in osteoclasts.
- Ferrous Iron-Dependent Volatilization of Mercury by the Plasma Membrane of Thiobacillus ferrooxidans