IRON-MEDIATED CHANGES IN THE GROWTH OF LAKE ERIE PHYTOPLANKTON AND AXENIC ALGAL CULTURES

Autor: Thomas A. Storch, Valgene L. Dunham
Rok vydání: 1986
Předmět:
Zdroj: Journal of Phycology. 22:109-117
ISSN: 1529-8817
0022-3646
DOI: 10.1111/j.1529-8817.1986.tb04152.x
Popis: The effect of iron enrichment on algal growth and photosynthesis was investigated using natural assemblages of Lake Erie phytoplankton and axenic cultures of Anabaena, Scenedesmus and Selenastrum. Cell yield and photosynthesis were frequently inhibited in the presence of unchelated iron over the range of 3.6 to 53.7 μM iron as FeCl3. In lake water and in a defined medium with low nutrient concentrations, the degree of inhibition by iron could be reduced by chelating the iron with EDTA or by enriching the cultures with phosphorus. Chemical analyses revealed that the EDTA efectively reduced the ability of the ferric iron to remove soluble phosphorus from the media. EDTA was also observed to reduce rather than enhance iron uptake by axenic cultures of A. flos-aquae. These data support the hypothesis that additions of EDTA to low-nutrient media may serve to stimulate algal growth in the presence of iron by preventing the iron from altering extracellular concentrations of soluble ions essential for algal metabolism. In medium with high nutrient concentrations, the soluble phosphorus concentration was not appreciably altered by either EDTA-chelated or unchelated iron enrichment (0.9 to 53.7 μM). Instead, the observed enhancement of cell yield by EDTA-chelated iron in nutrient-rich media appeared to be due to the direct effect of iron on intracellular metabolic processes.
Databáze: OpenAIRE
Externí odkaz: