Iron is an essential nutrient as a constituent of vital enzymes containing heme, iron-sulfur clusters, or iron cofactors. To ensure iron availability and to minimize oxidative stress triggered by Fe²⁺, bacteria accumulate Fe³⁺ minerals in iron storage proteins (ISPs), such as ferritin. Important features of ISPs are still unknown, such as the mechanism and control of iron release from ISPs, the importance of ISPs for the dynamics of iron homeostasis, the influence of ISPs on cellular metabolism and stress responses, and the significance of ISPs in the race for iron within microbial communities. To address these open questions, we will use Corynebacterium glutamicum as host and combine microbiological and biophysical research approaches.