Vibrio fischeri siderophore production drives competitive exclusion during dual-species growth.

TitleVibrio fischeri siderophore production drives competitive exclusion during dual-species growth.
Publication TypeJournal Article
Year of Publication2020
AuthorsEickhoff, MJ, Bassler, BL
JournalMol Microbiol
Volume114
Issue2
Pagination244-261
Date Published2020 08
ISSN1365-2958
Abstract

<p>When two or more bacterial species inhabit a shared niche, often, they must compete for limited nutrients. Iron is an essential nutrient that is especially scarce in the marine environment. Bacteria can use the production, release, and re-uptake of siderophores, small molecule iron chelators, to scavenge iron. Siderophores provide fitness advantages to species that employ them by enhancing iron acquisition, and moreover, by denying iron to competitors incapable of using the siderophore-iron complex. Here, we show that cell-free culture fluids from the marine bacterium Vibrio fischeri ES114 prevent the growth of other vibrio species. Mutagenesis reveals the aerobactin siderophore as the inhibitor. Our analysis reveals a gene, that we name aerE, encodes the aerobactin exporter, and LuxT is a transcriptional activator of aerobactin production. In co-culture, under iron-limiting conditions, aerobactin production allows V. fischeri ES114 to competitively exclude Vibrio harveyi, which does not possess aerobactin production and uptake genes. In contrast, V. fischeri ES114 mutants incapable of aerobactin production lose in competition with V. harveyi. Introduction of iutA, encoding the aerobactin receptor, together with fhuCDB, encoding the aerobactin importer are sufficient to convert V. harveyi into an "aerobactin cheater."</p>

DOI10.1111/mmi.14509
Alternate JournalMol Microbiol
PubMed ID32259318
PubMed Central IDPMC7541421
Grant List / HHMI / Howard Hughes Medical Institute / United States
R37 GM065859 / GM / NIGMS NIH HHS / United States
T32 GM007388 / GM / NIGMS NIH HHS / United States