Extracellular Fe(III) reduction by marine diatoms
- McGill Univ., Montreal, Quebec (Canada)
Marine diatoms of the genus Thalassiosira possess membrane proteins that extracellularly reduce Fe(III) in organic complexes as part of an Fe transport mechanism. Iron bound to EDTA, DTPA and to the fungal siderophore, desferrioxamine B, is reduced by these photoautotrophs and used for growth. The rates of reduction are twice as fast in cells grown on NO{sub 3}{sup -} compared to those grown on NH{sub 4}{sup +}, suggesting a link to cellular N metabolism and to NO{sub 3}{sup -} reduction in particular. High concentrations of NO{sub 3}{sup -} (50{mu}M) inhibit Fe(III) reduction rates by 50% and decrease Fe transport rates by an equivalent amount. Ammonium has no effect on Fe reduction or uptake. Under Fe-limiting conditions, reduction rates increase. Because a large fraction of dissolved Fe in the open sea is bound in strong organic complexes, this reductive mechanism may be a critical step in Fe acquisition by phytoplankton.
- OSTI ID:
- 210504
- Report Number(s):
- CONF-9509139-; TRN: 95:008324-0369
- Resource Relation:
- Conference: 7. ACS special symposium: emerging technologies in hazardous waste management, Atlanta, GA (United States), 17-20 Sep 1995; Other Information: PBD: 1995; Related Information: Is Part Of Emerging technologies in hazardous waste management VII; Tedder, D.W. [ed.]; PB: 1352 p.
- Country of Publication:
- United States
- Language:
- English
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