Fluorescent Pseudomonas mainly produce the dihydro form of pyoverdine at low specific growth rate.
OBJECTIVE
To analyse the influence of cell growth rate and iron concentration on the production of pyoverdines (PVDs) and of their reduced dihydro forms by three fluorescent Pseudomonas strains (P. putida BTP16, P. fluorescens BTP7 and P. aeruginosa 7NSK2).


METHODS
PVD and dihydropyoverdine (DHPVD) productions were determined by LC ESI-MS and spectrophotometry during batch and chemostat culture at different dilution rates.


CONCLUSIONS
The relatively high PVD-to-DHPVD ratio (0.57) observed in pH-controlled batch cultures suggested that a base-catalysed chemical oxidation of the dihydroform is not the prime mechanism involved in generating PVDs. Interestingly, in chemostat cultures the PVD-to-DHPVD ratio was significantly reduced at low specific growth rate. Our results suggest that the oxidation of DHPVD to PVD is catalysed by an iron-dependent enzymatic reaction rather than a chemical oxidation.
Jacques
P
P
Centre Wallon de Biologie Industrielle, Unité de Bioindustries, Faculté universitaire des Sciences agronomiques, B-5030 Gembloux, Belgium. jacques.p@fsagx.ac.be
Ongena
M
M
Bernard
F
F
Fuchs
R
R
Budzikiewicz
H
H
Thonart
P
P
D018533:Biomass; D005285:Fermentation; D005453:Fluorescence; D009842:Oligopeptides; D010860:Pigments, Biological / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism*; D011549:Pseudomonas / Q000737:chemistry / Q000254:growth & development* / Q000378:metabolism*; D011550:Pseudomonas aeruginosa / Q000254:growth & development / Q000378:metabolism; D011551:Pseudomonas fluorescens / Q000254:growth & development / Q000378:metabolism; D016958:Pseudomonas putida / Q000254:growth & development / Q000378:metabolism
D009842:Oligopeptides; D010860:Pigments, Biological; C042453:pyoverdin