iron uptake assignment in microbiology
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Answer:This work describes the presence of high-affinity iron uptake systems in Vibrio anguillarum serotype O3 strains (subgroups A and B), isolated from diseased fish and environmental samples, as well as the presumptive effect of iron on their virulence. All strains demonstrated an ability to grow under iron-limiting conditions, production of catechol-type siderophores and synthesis of iron-regulated outer membrane proteins. However, clear differences were found depending on the isolation source, suggesting a more efficient iron uptake system in fish-isolated strains. Comparing the iron-regulated outer membrane protein profiles with those described for O1 and O2 serotypes, we found a protein which is specific for serotype O3, and another one that allows the differentiation of serotype O3 fish isolates from environmental strains. Moreover, only the strains showing this protein increased their virulence when iron was added to the inoculum in pathogenicity assays.
Explanation:
SUMMARY: Among several parameters affecting the rate and amount of iron uptake by Saccharomyces cerevisiae, the oxidation state of iron appeared to be determinant. Iron presented as Fe(II) was taken up faster than Fe(III) and the kinetic parameters were different. Iron was taken up by the cells from different ferric chelates, at rates that did not depend on their stability constants, and uptake was strongly inhibited by an iron(II)-trapping reagent like ferrozine. Iron was physiologically reduced by a transplasmamembrane redox system, which was induced in iron-deficient conditions. We propose that iron must be reduced to be taken up by the cells in the same way as other divalent cations.