title: A broad mercury resistant strain of Pseudomonas putida secretes pyoverdine under limited iron conditions and high mercury concentrations.
abstract: The Pseudomonas putida FB1, known as a broad-spectrum mercury resistant strain, becomes yellow-green due to the secretion of pyoverdine (PVDs) under limited iron conditions and high mercury concentrations. Different modified Nelson's media were obtained by adding mercury, iron, and the complexing agent nitrilotriacetic acid to demonstrate that the strain produces only the highest concentrations of PVDs due to the induction with 25 µM Hg2+. An amount of 250 mg PVDs was purified from the supernatant of 1 litre culture. The various forms of PVDs were characterized using different techniques such as fluorescence spectroscopy, high performance liquid chromatography coupled with high resolution mass spectrometry, and scanning electron microscope equipped with energy dispersive X-ray analyser. A set of "in vivo" experiments demonstrated that additions of Hg2+to the cultures from 10 to 25 µM Hg2+stimulate an over secretion of PVDs suggesting that the toxic cation strongly reduces the availability of apo-PVDs, because the complex mercuric-pyoverdine is very stable at neutral pH, and hinder the formation of PVDs-Fe(III).
authors.affiliation: Dipartimento di Scienze Molecolari e Nanosistemi, Cà Foscari University, Via Torino 155, 30172, Mestre, Venezia, Italy. baldi@unive.it.
authors.forename: Franco
authors.identifier: 0000-0003-3190-9009
authors.initials: F
authors.lastname: Baldi
authors.affiliation: Dipartimento di Scienze Molecolari e Nanosistemi, Cà Foscari University, Via Torino 155, 30172, Mestre, Venezia, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Gallo
authors.affiliation: Dipartimento di Scienze Ambientali, Informatica e Statistica, Cà Foscari University, Via Torino 155, 30172, Mestre, Venezia, Italy.|Institute for the Dynamics of Environmental Processes, IDPA/CNR, Via Torino 155, 30172, Mestre, Venezia, Italy.
authors.forename: Dario
authors.initials: D
authors.lastname: Battistel
authors.affiliation: Dipartimento di Scienze Ambientali, Informatica e Statistica, Cà Foscari University, Via Torino 155, 30172, Mestre, Venezia, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Barbaro
authors.affiliation: Dipartimento di Scienze Ambientali, Informatica e Statistica, Cà Foscari University, Via Torino 155, 30172, Mestre, Venezia, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Gambaro
authors.affiliation: Dipartimento di Scienze Molecolari e Nanosistemi, Cà Foscari University, Via Torino 155, 30172, Mestre, Venezia, Italy.
authors.forename: Salvatore
authors.initials: S
authors.lastname: Daniele
mesh_terms: D004305:Dose-Response Relationship, Drug; D024881:Drug Resistance, Bacterial; D005612:Freeze Drying; D008658:Inactivation, Metabolic; D007501:Iron / Q000494:pharmacology*; D008628:Mercury / Q000493:pharmacokinetics / Q000494:pharmacology*; D009842:Oligopeptides / Q000378:metabolism*; D016958:Pseudomonas putida / Q000737:chemistry / Q000187:drug effects* / Q000378:metabolism*
chemical_list: D009842:Oligopeptides; C042453:pyoverdin; D007501:Iron; D008628:Mercury
keywords: Cyclic voltammetry; Gaseous Hg(0); HPLC-HRMS method; Mercuric-pyoverdine; Pyoverdine; “In vivo” experiment