Abstract

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.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.