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The Hydrosphere and Water Chemistry
Published in Stanley E. Manahan, Environmental Chemistry, 2022
Although chelating agents are never entirely specific for a particular metal ion, some complicated chelating agents of biological origin approach almost complete specificity for certain metal ions. One example of such a chelating agent is ferrichrome, synthesized by and extracted from fungi, which forms extremely stable chelates with iron(III). It has been observed that cyanobacteria of the Anabaena species secrete appreciable quantities of iron-selective hydroxamate chelating agents during periods of heavy algal bloom. These photosynthetic organisms readily take up iron chelated by hydroxamate-chelated iron, whereas some competing green algae, such as Scenedesmus, do not. Thus, the chelating agent serves a dual function of promoting the growth of certain cyanobacteria while suppressing the growth of competing species, allowing the cyanobacteria to exist as the predominant species. The production of chelating agents selective for iron(III) has been observed in cyanobacterial Plectonema and Spirulina as well as Chlorella, Scenedesmus, and Porphyrium algae.
The Hydrosphere and Water Chemistry
Published in Stanley Manahan, Environmental Chemistry, 2017
Although chelating agents are never entirely specific for a particular metal ion, some complicated chelating agents of biological origin approach almost complete specificity for certain metal ions. One example of such a chelating agent is ferrichrome, synthesized by and extracted from fungi, which forms extremely stable chelates with iron(III). It has been observed that cyanobacteria of the Anabaena species secrete appreciable quantities of iron-selective hydroxamate chelating agents during periods of heavy algal bloom. These photosynthetic organisms readily take up iron chelated by hydroxamate-chelated iron, whereas some competing green algae, such as Scenedesmus, do not. Thus, the chelating agent serves a dual function of promoting the growth of certain cyanobacteria while suppressing the growth of competing species, allowing the cyanobacteria to exist as the predominant species. The production of chelating agents selective for iron(III) has been observed in cyanobacterial Plectonema and Spirulina as well as Chlorella, Scenedesmus, and Porphyrium algae.
Theoretical insight and experimental elucidation of desferrioxamine B from Bacillus sp. AS7 as a green corrosion inhibitor
Published in Corrosion Engineering, Science and Technology, 2021
S. Pérez-Miranda, L.S. Zamudio-Rivera, R. Cisneros-Dévora, R. George-Téllez, F.J. Fernández
The siderophore (compound 1) was characterised by 1H NMR, 13C NMR and IR spectroscopy. NMR spectra were obtained on a Varian Mercury 200-BB spectrometer; chemical shifts are given in parts per million (ppm). In all cases, the used solvent was deuterated water, and tetramethylsilane was used as an internal reference. IR spectra were obtained in a Bruker Tensor 27 spectrometer. The IR spectra were measured as KBr pellets. All solvents, HPLC grade, were obtained from J.T. Baker, the rest of the reagents were obtained from Sigma Aldrich. The 1 mg mL−1 aqueous stock solutions of the hydroxamate siderophore, ferrichrome, were prepared ahead and stored at 4°C.