TITLE

High stability ferric chelates result in decreased iron uptake by the green alga Chlorella kessleri owing to decreased ferric reductase activity and chelation of ferrous iron

AUTHOR(S)
Weger, Harold G.; Lam, Jackie; Wirtz, Nikki L.; Walker, Crystal N.; Treble, Ron G.
PUB. DATE
October 2009
SOURCE
Botany;Oct2009, Vol. 87 Issue 10, p922
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
Cells of the green alga Chlorella kessleri Fott et Nov�kov� use a reductive mechanism for iron acquisition. Iron-limited cells acquired iron more rapidly from a chelator with a lower stability constant for Fe3+ (hydroxyethylethylenediaminetriacetic acid (HEDTA)) than from a chelator with a higher stability constant (N,N'-di[2-hydroxybenzyl)ethylenediamine-N,N'-diacetic acid (HBED)). Furthermore, iron uptake rates decreased with increasing chelator concentrations at constant iron concentration. The negative effects of elevated HBED levels on iron uptake could be partly alleviated by the addition of Ga3+, which suggests that iron-free chelator has a negative effect on iron acquisition by competing for Fe2+ with the ferrous transport system. Furthermore, ferric reductase activity progressively decreased with increasing concentrations of both chelators (in the iron-free form). This effect was not alleviated by Ga3+ addition and was apparently caused by the direct inhibition of the reductase. Overall, we conclude that chelators with high stability constants for Fe3+ decrease iron acquisition rates by Strategy I organisms via three separate mechanisms.
ACCESSION #
44461628

 

Related Articles

Share

Read the Article

Courtesy of THE LIBRARY OF VIRGINIA

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics