Mycobactin is a

siderophore Siderophores (Greek: "iron carrier") are small, high-affinity iron- chelating compounds that are secreted by microorganisms such as bacteria and fungi. They help the organism accumulate iron. Although a widening range of siderophore functions is n ...

used by members of the genus '' Mycobacterium'' to shuttle free extracellular iron ions into the cytoplasm of mycobacterial cells. The pathogen ''M. tuberculosis'' can synthesize its own mycobactin for this purpose, however there are other mycobacteria such as '' M. avium'' subspecies ''

paratuberculosis Paratuberculosis is a contagious, chronic and sometimes fatal infection that primarily affects the small intestine of ruminants. It is caused by the bacterium ''Mycobacterium avium'' subspecies ''paratuberculosis''. Infections normally affect ru ...

'' that cannot produce this siderophore and thus it must be supplied to cultivate this organism in the lab.

References

{{Reflist Siderophores