Complex Iron Uptake by the Putrebactin-Mediated and Feo Systems in Shewanella oneidensis

S. oneidensis is among the first- and the best-studied metal-reducing bacteria, with great potential in bioremediation and biotechnology. However, many questions regarding mechanisms closely associated with those applications, such as iron homeostasis, including iron uptake, export, and regulation, remain to be addressed. Here we show that Feo is a primary player in iron uptake in addition to the siderophore-dependent route. The investigation also resolved a few puzzles regarding the unexpected phenotypes of theputA mutant and lactate-dependent iron uptake. By elucidating the physiological roles of these two important iron uptake systems, this work revealed the breadth of the impacts of iron uptake systems on the biological processes.