Siderophores produced by marine microorganisms.

Siderophores are iron-chelating, low-molecular-weight compounds secreted by microorganisms in iron-deficient environments that enhance iron uptake. When compared to the siderophores produced by terrestrial microorganisms, marine siderophores have been shown to have diverse structures and physiological functions. Fifty-seven strains of marine microorganisms have been identified as siderophore producers so far. Among them, 54 bacterial strains belong to 23 genera of 19 families in five phyla, and three fungal strains belong to three genera of three families in two phyla. The most common source of siderophores is seawater, which has a wide depth distribution. A total of 105 siderophores from marine microorganisms had been reported by 2024. These siderophores are mainly divided into five types depending on their functional groups and hydrophobicity: hydroxamates, catecholates, carboxylates, mixed, and other types. The most common marine siderophore is hydroxamate. The amphiphilicity of marine microbial siderophores distinguishes them from those produced by terrestrial microorganisms. This review discusses the recent findings in marine siderophore biology and highlights the potential of siderophores in medicine, fish disease control, bioremediation, and biosensors.