Vanadium requirements and uptake kinetics in the dinitrogen-fixing bacterium Azotobacter vinelandii

The vanadium (V)-requirements, the kinetics of V uptake, and the production of catechol compounds are examined across a range of concentrations of vanadium in diazotrophic cultures of the soil bacterium Azotobacter vinelandii. The modulation of the excretion of catechols and of the uptake of the V-catechol complexes has allowed Azotobacter vinelandii to manage its V homeostasis over a range of V concentrations, from limiting to toxic.