Transient O2 pulses direct Fe crystallinity and Fe(III)-reducer gene expression within a soil microbiome.

This study demonstrates that specific Fe(III)-reduction mechanisms in mixed Fe(III)-reducer populations are uniquely sensitive to the rate of O2 influx, likely mediated by shifts in soil Fe(III)-(oxyhydr)oxide crystallinity. Overall, we provide evidence that transient oxygenation events play an important role in directing anaerobic pathways within soil microbiomes, which is expected to alter Fe and C cycling in redox-dynamic environments.