Characterization of the ferrioxamine uptake system of Nitrosomonas europaea

Microbiology. 2007 Dec;153(Pt 12):3963-3972. doi: 10.1099/mic.0.2007/010603-0.


The chemolithoautotroph Nitrosomonas europaea has two genes predicted to encode outer-membrane (OM) ferrioxamine transporters. Expression of the ferrioxamine uptake system required induction, as shown by the shorter lag phase in ferrioxamine-containing cultures when ferrioxamine-exposed cells were used as an inoculum. The two OM ferrioxamine siderophore transporters encoded by foxA(1) (NE1097) and foxA(2) (NE1088) were produced only in cells grown in Fe-limited ferrioxamine-containing medium. The inactivation of foxA(1), singly or in combination with foxA(2), prevented growth in Fe-limited medium containing excess desferrioxamine (DFX). The foxA(2)-disrupted single mutant grew poorly in the regular Fe-limited (0.2 microM) medium with 10 microM DFX, but grew well when the Fe level was raised to 1.0 microM with 10 microM DFX. For efficient acquisition of Fe-loaded ferrioxamine, N. europaea needs both ferrioxamine transporters FoxA(1) and FoxA(2). FoxA(1) probably regulates its own production, and it controls the production of FoxA(2) as well.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Bacterial Outer Membrane Proteins* / chemistry
  • Bacterial Outer Membrane Proteins* / genetics
  • Bacterial Outer Membrane Proteins* / metabolism
  • Deferoxamine / metabolism*
  • Ferric Compounds / metabolism*
  • Gene Expression Regulation, Bacterial*
  • Iron / metabolism*
  • Iron Chelating Agents / metabolism
  • Molecular Sequence Data
  • Nitrosomonas europaea / genetics
  • Nitrosomonas europaea / growth & development
  • Nitrosomonas europaea / metabolism*
  • Receptors, Cell Surface* / chemistry
  • Receptors, Cell Surface* / genetics
  • Receptors, Cell Surface* / metabolism


  • Bacterial Outer Membrane Proteins
  • Ferric Compounds
  • FoxA protein, bacteria
  • Iron Chelating Agents
  • Receptors, Cell Surface
  • ferrioxamine B
  • Iron
  • Deferoxamine