title: The Siderophore Metabolome of Azotobacter vinelandii.
abstract: In this study, we performed a detailed characterization of the siderophore metabolome, or "chelome," of the agriculturally important and widely studied model organism Azotobacter vinelandii. Using a new high-resolution liquid chromatography-mass spectrometry (LC-MS) approach, we found over 35 metal-binding secondary metabolites, indicative of a vast chelome in A. vinelandii. These include vibrioferrin, a siderophore previously observed only in marine bacteria. Quantitative analyses of siderophore production during diazotrophic growth with different sources and availabilities of Fe showed that, under all tested conditions, vibrioferrin was present at the highest concentration of all siderophores and suggested new roles for vibrioferrin in the soil environment. Bioinformatic searches confirmed the capacity for vibrioferrin production in Azotobacter spp. and other bacteria spanning multiple phyla, habitats, and lifestyles. Moreover, our studies revealed a large number of previously unreported derivatives of all known A. vinelandii siderophores and rationalized their origins based on genomic analyses, with implications for siderophore diversity and evolution. Together, these insights provide clues as to why A. vinelandii harbors multiple siderophore biosynthesis gene clusters. Coupled with the growing evidence for alternative functions of siderophores, the vast chelome in A. vinelandii may be explained by multiple, disparate evolutionary pressures that act on siderophore production.
authors.affiliation: Department of Geosciences, Princeton University, Princeton, New Jersey, USA.
authors.forename: Oliver
authors.initials: O
authors.lastname: Baars
authors.affiliation: Department of Geosciences, Princeton University, Princeton, New Jersey, USA.
authors.forename: Xinning
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Department of Geosciences, Princeton University, Princeton, New Jersey, USA morel@princeton.edu mrseyed@princeton.edu.
authors.forename: François M M
authors.initials: FM
authors.lastname: Morel
authors.affiliation: Department of Chemistry, Princeton University, Princeton, New Jersey, USA morel@princeton.edu mrseyed@princeton.edu.
authors.forename: Mohammad R
authors.initials: MR
authors.lastname: Seyedsayamdost
mesh_terms: D016948:Azotobacter vinelandii / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D053898:Biosynthetic Pathways; D002853:Chromatography, Liquid; D013058:Mass Spectrometry; D055442:Metabolome; D017262:Siderophores / Q000096:biosynthesis* / Q000737:chemistry
chemical_list: D001426:Bacterial Proteins; D017262:Siderophores