Articles

Title:	The marine diatom Cyclotella meneghiniana Kutzing as a producer of siderophore-like substances
Authors:	Cabaj Agnieszka Kosakowska Alicja
Abstract:	Iron(III) plays an important role in biochemical processes occurring in plants and phytoplankton. Under iron deficiency (< 10-5 mol dm^-3), most microorganisms activate a high-affinity iron acquisition system, producing and secreting iron(III)-specific chelators called siderophores. The aim of this study was to assess the influence of the ionic and complexed form of iron(III) on the production of siderophore-like substances by the marine diatom Cyclotella meneghiniana Kűtzing (SAG 1020-1a). The growth parameters measured were the number of cells and the content of chlorophyll a and protein. The production of siderophores was determined by non-specific (Cu-CAS) and specific (Csaky, Arnow) chemical tests and by biological tests with the bacteria mutants Morganella morganii SBK-3, Salmonella typhimurium enb-7 and Microbacterium flavescens JG-9. The results obtained show that both the concentration and physico-chemical form of iron(III) influence the number of cells and the content of chlorophyll a per cell, but not the content of protein per cell. The optimum concentration of Fe (10-5 mol dm^-3) stimulated growth and chlorophyll a production, while iron stress in ionic form inhibited both of these. However, the enrichment of the medium with a complexing factor (EDTA) evidently promoted growth and chlorophyll a production. Siderophore-like substances were found to be active under both iron deficiency (in ionic and complexed forms) and sufficiency. It has been demonstrated that C. meneghiniana can produce hydroxamate-type siderophores and α-keto-/α-hydroxyacids, but it probably does not produce catecholates.
DOI:
Type of paper:	Original research paper
Pages:	57 to 72
Cytation:	Cabaj A., Kosakowska A., 2005, The marine diatom Cyclotella meneghiniana Kutzing as a producer of siderophore-like substances, Ocean. Hydrob. Studies, 34(1): 57-72
Keywords:	iron, siderophore-like substances, marine diatom
Year:	2005
Category:
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