A continuous culturing system (chemostat) made of metal-free materials was successfully developed and used to maintain Fe-limited cultures of Microcystis aeruginosa PCC7806 at nanomolar iron (Fe) concentrations (20 to 50 nM total Fe). EDTA was used to maintain Fe in solution, with bioavailable Fe controlled by absorption of light by the ferric EDTA complex and resultant reduction of Fe(III) to ...

Iron-sufficient cells of the green alga Scenedesmus incrassatulus Bohl, R-83 released in the medium strong and weak Fe3+-complexing agents in response to freshly added Fe3+. Applied in the dark, photosynthetic inhibitor 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) inhibited ferric reduction from ferric-EDTA or ferricyanide more than the chelator release. Fedeficient cells and DCMU-treated Fe-...

The effects of ferric ammonium citrate (FAC) and desferrioxamine (DFO) on iron (Fe), and transferrin (Tf) uptake have been investigated using SK-MEL-28 human melanoma cells, which express the Tf homologue, melanotransferrin, in high concentrations. Previously we demonstrated two separate Fe uptake mechanisms from Tf, viz. a specific process mediated by the transferrin receptor (TfR) and a nonsp...

Expansion of a polyglutamine tract in Huntingtin (Htt) leads to the degeneration of medium spiny neurons in Huntington's disease (HD). Furthermore, the HTT gene has been functionally linked to iron (Fe) metabolism, and HD patients show alterations in brain and peripheral Fe homeostasis. Recently, we discovered that expression of mutant HTT is associated with impaired manganese (Mn) uptake follo...

This study aims to understand the enhancing effect of glycosaminoglycans (GAGs), such as chondroitin/dermatan structures, on Fe uptake to Caco-2 cells. High-sulfated GAGs were selectively purified from cooked haddock. An in vitro digestion/Caco-2 cell culture model was used to evaluate Fe uptake (cell ferritin formation) from a Fe(+3)-containing solution, and Fe(+3)/ascorbic acid (AA) and Fe(+3...

The uptake of arsenate (As(V)) and dimethylarsinic acid (DMAA) by aquatic macrophyte Spirodela polyrhiza L. was investigated to determine the influence of arsenic interaction with PO4(3-) and Fe ions. Plants were grown hydroponically on standard Murashige and Skoog (MS) culture solutions. Arsenic concentrations in Fe-oxide (Fe-plaque) on plant surfaces were determined by citrate-bicarbonate-eth...

The important question of iron bioavailability in the sea has become complicated by the discovery that marine phytoplankton can take up Fe bound in very stable chelates via reductive processes, and some particular Fe species through specialized transport mechanisms. As a result there is some question of whether the small fraction of Fe that is ‘‘free’’ or unchelated in seawater is important in ...

The important question of iron bioavailability in the sea has become complicated by the discovery that marine phytoplankton can take up Fe bound in very stable chelates via reductive processes, and some particular Fe species through specialized transport mechanisms. As a result there is some question of whether the small fraction of Fe that is ‘‘free’’ or unchelated in seawater is important in ...