Organisms acquire some elements from the environment with ease. Diffusion alone often provides enough carbon dioxide, oxygen and water. But getting other elements requires more effort, spurring unique evolutionary adaptations: instead of taking up nutrients from the soil, some plants in acidic bogs trap insects to obtain nitrogen and phosphorus 1; geophagy — or eating dirt — may sometimes be important for acquiring iron by primates 2; plants and microorganisms secrete compounds that liberate phosphorus from unavailable forms in soil 3; and many bacteria secrete metal-scavenging compounds called siderophores to capture iron and copper 4,5. Evidence has mounted that molybdenum is also specifically targeted 6. On page 243 of this issue, Bellenger and colleagues 7 confirm this, showing that siderophores produced by the nitrogen-fixing bacterium Azotobacter vinelandiibind with molybdenum and vanadium in the laboratory, promoting uptake of these metals.
Read Publication