Siderophore activity of pyoverdin for Pseudomonas aeruginosa

Abstract

Pseudomonas aeruginosa produces an extracellular compound with yellowish green fluorescence, called pyoverdin, which functions as a siderophore. The production of pyoverdin, formerly called fluorescein, is concomitant with the production of another siderophore, pyochelin. Pyoverdin is produced by P. aeruginosa in several forms, some of which were separated on gel filtration columns and on reverse-phase, high-pressure liquid chromatography columns. An active form of iron-free pyoverdin was purified to homogeneity. The elution of pyoverdin from the columns was monitored for absorbance, fluorescence, and siderophore activities. These activities, iron binding, and the stimulation of bacterial iron transport indicated that pyoverdin can function as a siderophore for P. aeruginosa. The siderophore function of pyoverdin may be related to the pathogenicity of this bacterium because pyoverdin stimulated growth not only in iron-deficient culture medium, but also in defined medium containing transferrin and in human serum or plasma.

Dynamic social behaviour in a bacterium:Pseudomonas aeruginosapartially compensates for siderophore loss to cheats

“…Pyoverdine production of bacterial cultures was assayed by a pyoverdine-specific excitation-emission assay: the relative fluorescence of 100 lL of culture at 460 nm following excitation at 400 nm was measured using a SpectraMax M2 spectrophotometer (Ankenbauer et al, 1985;Cox & Adams, 1985;Jiricny et al, 2010).…”

Iron uptake mechanisms of pathogenic bacteria

“…Pseudomonas aeruginosa strains produce two siderophores, pyoverdin and pyochelin [185], the former a large molecule comprising a hexapeptide backbone, a dihydroxyquinoline moiety and two N-hydroxyornithine residues [186], and the latter a salicylic acid substituted cysteinyl peptide [187]. A 14-kDa outer membrane protein, which is synthesised concomitantly with pyochelin and which binds ferripyochelin, may function as the receptor for this siderophore [188], and mutant strains not expressing this protein were avirulent [189].…”

PchR‐box recognition by the AraC‐type regulator PchR of Pseudomonas aeruginosa requires the siderophore pyochelin as an effector

“…In the Gram-negative bacterium Pseudomonas aeruginosa iron is acquired with two endogenous siderophores, pyoverdine (Meyer and Abdallah, 1978;Cox and Adams, 1985) and pyochelin (Cox, 1980;Rinehart et al ., 1995), which both contribute to the virulence of this opportunistic human pathogen (Cox, 1982;Meyer et al ., 1996;Takase et al ., 2000). The biosynthesis of these siderophores and their cognate receptors FpvA (for pyoverdine; Poole et al ., 1993) and FptA (for pyochelin; Ankenbauer and Quan, 1994) is controlled by negative and positive regulation.…”