Article,
The influence of zinc, aluminum and cadmium on the uptake kinetics of iron by algae
MARINE CHEMISTRY, 59 (1-2): 95--111 (1997)
Abstract
The uptake of iron by the marine diatom Thalassiosira weissflogii
and the green algae Dunaliella tertiolecta in seawater has been investigated.
Computations were made of the rate constants for the binding of iron
to specific cell surface-associated transport ligands and the subsequent
slow active uptake into the cytoplasm of the cells. Although both
algae transport Fe, the sorption constants and the kinetic parameters
are markedly different and temperature dependent. The sorption constants,
which are one order of magnitude higher for T weissflogii versus
D. tertiolecta (2.5 X 10(-9) l cell(-1) vs. 2.2 X 10(-10) l cell(-1))
at 25 degrees C, give us a measure of the theoretical number of transport
sites needed by each cell. The effects on the iron speciation and
on the rate of iron uptake due to the addition of different concentrations
of Zn(II), AL(III) and Cd(II) have also been determined. The results
confirm that while iron is taken up via specific sites on the cell
surfaces, synergistic and antagonistic effects on the iron rate uptake
for T. weissflogii and D. tertiolecta, respectively, have been found
and evaluated. (C) 1997 Elsevier Science B.V.
Tags
- chlorella-vulgaris;
- complexation;
- diatom
- equatorial
- growth;
- natural-waters;
- pacific;
- phytoplankton
- productivity;
- seawater;
- thalassiosira-weissflogii;
- trace-metals;
- transport
