Iron plays an important role in the pathogenesis and rhizosphere competence of the fluorescent group of pseudomonads and it is, thus, fitting that the characteristic fluorescence of these organisms is attributable to an iron-chelating molecule, pyoverdine. Pseudomonas aeruginosa is likely the best-studied member of this group, and while it synthesizes two siderophores, pyochelin and pyoverdine,...

The effect of growth at 42 degrees C on the different components of the siderophore-mediated iron transport that are induced by iron limitation in Azospirillum brasilense was examined. Biosynthesis of the siderophore spirilobactin was strongly inhibited (20-fold) by growth at 42 degrees C, whereas the transport of iron by the ferric-spirilobactin transport system and the induction of the iron-r...

It has been demonstrated that under iron-restricted conditions Bordetella pertussis can take up iron from human transferrin within 30 min of exposure. B. pertussis utilizes two mechanisms for acquiring iron from human transferrin, a direct contact method and a siderophore mediated system. Both systems are shown to result in bacterial internalization of iron from transferrin. However, direct con...

The effect of amphoteric siderophore deferoxamine on the crystallization behavior of calcium carbonate was investigated under bioinspired conditions. Amphoteric siderophore deferoxamine possesses selforganization ability, surface activity and ion-chelating properties. It induces in the present case the formation of unusual, highly organized aragonite mesocrystals during the precipitation of cal...

Siderophores are essential factors for iron (Fe) acquisition in bacteria during colonization and infection of eukaryotic hosts, which restrain iron access through iron-binding protein, such as lactoferrin and transferrin. The synthesis of siderophores by Escherichia coli is considered to be fully regulated at the transcriptional level by the Fe-responsive transcriptional repressor Fur. Here we ...

From our experimental evidence that iron lirnitation greatly increases the extracellular concentration of strong copper-complexing agents in cultures of Anabaena flos-aquae and Anabaena cyhdrica, and that the iron-algal exudate complex is much more stable than the copper complex, we conclude that strong copper-complexing agents released by filamentous blue-green algae are siderophores. Further ...

Iron deprivation activates the expression of components of the siderophore-mediated iron acquisition systems in Bacillus subtilis, including not only the synthesis and uptake of its siderophore bacillibactin but also expression of multiple ABC transporters for iron scavenging using xenosiderophores. The yclNOPQ operon is shown to encode the complete transporter for petrobactin (PB), a photoreac...

Iron is an essential nutrient required for a wide range of cellular processes. The opportunistic fungal pathogen Aspergillus fumigatus employs low-molecular mass iron-specific chelators, termed siderophores, for uptake, storage and intracellular iron distribution, which play a crucial role in the pathogenicity of this fungus. Siderophore biosynthesis (SB) depends on coordination with the supply...

A rhizobacterium isolated from groundnut rhizosphere and identified as Alcaligenes faecalis BCCM 2374 produced siderophore during 24 h submerged growth in modified succinic acid medium (SM) prepared in tap water without deferration. For the optimized production of siderophore in the presence of starch and sucrose, the optimum parameters found were as follows: slight acidic pH (5.5), 35C tempera...

Siderophore facilitates iron availability in soil, but its assistance in iron transportation to different plant parts is not reported till date. Therefore, it is worthwhile to study the effect of siderophore produced by Pseudomonas for iron acquisition in the presence and absence of iron. To study these effects, two siderophore-producing Pseudomonas aeruginosa strains RSP5 and RSP8 were selecte...