The Siderophore Metabolome of Azotobacter vinelandii.

TitleThe Siderophore Metabolome of Azotobacter vinelandii.
Publication TypeJournal Article
Year of Publication2016
AuthorsBaars, O, Zhang, X, Morel, FMM, Seyedsayamdost, MR
JournalAppl Environ Microbiol
Volume82
Issue1
Pagination27-39
Date Published2016 01 01
ISSN1098-5336
KeywordsAzotobacter vinelandii, Bacterial Proteins, Biosynthetic Pathways, Chromatography, Liquid, Mass Spectrometry, Metabolome, Siderophores
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.

DOI10.1128/AEM.03160-15
Alternate JournalAppl. Environ. Microbiol.
PubMed ID26452553
PubMed Central IDPMC4702634