Microbial growth and community interactions are influenced by a multitude of factors. A new mode of
Streptomycesgrowth—exploration—is promoted by interactions with the yeast Saccharomyces cerevisiaeand requires the emission of trimethylamine (TMA), a pH-raising volatile compound. We show here that TMA emission also profoundly alters the environment around exploring cultures. It specifically reduces iron availability, and this in turn adversely affects the viability of surrounding microbes. Paradoxically, Streptomycesbacteria thrive in these iron-depleted niches, both rewiring their gene expression and metabolism to facilitate iron uptake and increasing their exploration rate. Growth in close proximity to other microbes adept at iron uptake also enhances exploration. Collectively, the data from this work reveal a new role for bacterial volatile compounds in modulating nutrient availability and microbial community behavior. The results further expand the repertoire of interspecies interactions and nutrient cues that impact Streptomycesexploration and provide new mechanistic insight into this unique mode of bacterial growth.