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Low availability of micronutrients such as iron has enforced the evolution of uptake systems in all kingdoms of life. In Gram-negative bacteria, outer membrane, periplasmatic and plasma membrane localized proteins facilitate the uptake of iron-loaded chelators, which are energized by TonB proteins. The specificity of different uptake systems likely depends either on the endogenously produced siderophore or on the bioavailability of iron-chelator complexes in the environment. Hence, an uptake system for schizokinen produced by the model cyanobacterium <i>Anabaena</i> sp. PCC 7120 exists, while bioinformatics analysis suggests the existence of additional systems, likely for uptake of xenosiderophores. Consistently, proteins encoded by <i>alr2153</i> (<i>hutA1</i>) and <i>alr3242</i> (<i>hutA2</i>) are assigned as outer membrane heme transporters. Indeed, <i>Anabaena</i> sp. PCC 7120 can utilize external heme as an iron source. The addition of heme resulted in an induction of genes involved in heme degradation and chlorophyll <i>a</i> synthesis and in an increase of the chlorophyll <i>a</i> content. Moreover, iron starvation induced the expression of <i>hutA1</i>, while the addition of heme led to its repression. Remarkably, the addition of a high concentration of heme but not iron starvation resulted in <i>hutA2</i> induction. Plasmid insertion mutants of both genes exhibited a reduced capacity to recover from iron starvation by heme addition, which indicates a dependence of heme uptake on functional HutA1 and HutA2 proteins. The structural model generated by bioinformatics methods is further in agreement with a role in heme uptake. Thus, we provide evidence that <i>Anabaena</i> sp. PCC 7120 uses a heme uptake system in parallel to other iron acquisition systems.