The Siderophore Metabolome of Azotobacter vinelandii. Author Oliver Baars, Xinning Zhang, François Morel, Mohammad Seyedsayamdost Publication Year 2016 Type Journal Article 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. Keywords Bacterial Proteins, Mass Spectrometry, Chromatography, Liquid, Biosynthetic Pathways, Siderophores, Azotobacter vinelandii, Metabolome Journal Appl Environ Microbiol Volume 82 Issue 1 Pages 27-39 Date Published 2016 Jan 01 ISSN Number 1098-5336 DOI 10.1128/AEM.03160-15 Alternate Journal Appl Environ Microbiol PMCID PMC4702634 PMID 26452553 PubMedPubMed CentralGoogle ScholarBibTeXEndNote X3 XML