Data from: Competition for iron shapes metabolic antagonism between Bacillus subtilis and Pseudomonas

<p>Siderophores have long been implicated in sociomicrobiology as determinants of bacterial interrelations. For plant-associated genera like <em>Bacillus</em> and <em>Pseudomonas</em>, siderophores are often acclaimed for their function in biocontrol. Here, we set out to determine the functional role of the<em> Bacillus subtilis</em> siderophore bacillibactin in an antagonistic interaction with <em>Pseudomonas marginalis</em>. The presence of bacillibactin strongly influences the outcome of the interaction in an iron-dependent manner. A bacillibactin producer <em>B. subtilis</em> restricts the colony spreading of <em>P. marginalis</em>, repress the transcription of histidine kinase-encoding gene <em>gacS</em>, and thereby abolish production of secondary metabolites such as pyoverdine and viscosin. In contrast, the lack of bacillibactin restricts <em>B. subtilis</em> colony growth in a mechanism reminiscent of a siderophore tug-of-war for iron. Our study identifies a <em>Bacillus-Pseudomonas</em> interaction conserved across fluorescent <em>Pseudomonas spp.</em>, expanding our understanding of the interplay between two genera of the most well-studied soil microbes.</p>