Siderophores cyanobacteria

Wilhelm, S. W. and Trick, C. G. (1994). Iron-limited growth of cyanobacteria -multiple siderophore production is a common response, Limnol. Oceanogr., 39, 1979-1984. 

The nonprotein amino acid /3-A -methylamino-L-alanine (BMAA) is a neurotoxin found in various species of marine cyanobacteria. This nonprotein amino acid occurs both as a free amino acid and bound to proteins.Siderophores are secondary metabolites generally produced by bacteria under iron-deficient conditions. These molecules sequester and transport ferric ion via active transport in bacteria. Some known siderophores are nonribosomal peptides that contain nonprotein amino acids with terminal amines or hydroxylamine side chains, such as exochelin Many of the known nonprotein amino... 

Cyanobacteria were probably the first organisms to perform oxygenic photosynthesis resulting eventually in the oxidation of environmental Fe " to Fe " with all its consequences. To cope with this problem the production of siderophores was initiated. Not much is known about the siderophores of cyanobacteria. Schizokinen (see below under citrate siderophores, Sect. 4.1) (326) found to be produced by several bacterial species may have been acquired by gene transfer see however also the citrate siderophores synechobactins. 

Barbeau K, Rue EL, Trick CG, Bruland KW, Butler A (2003) Photochemical Reactivity of Siderophores Produced by Marine Heterotrophic Bacteria and Cyanobacteria Based on Characteristic Fe(III) Binding Groups. Lirrmol Oceanogr 48 1069... 

Barbeau, K., Rue, E. L., Trick, C. G., Bruland, K. T., and Butler, A. (2003). Photochemical reactivity of siderophores produced by marine heterotrophic bacteria and cyanobacteria based on characteristic Fe(III) binding groups. Limnol. Oceanogr. 48, 1069-1078. 

Kerry, A., D. E. Laudenbach, and C. G. Trick (1988), Influence of Iron Limitation and Nitrogen Source on Growth and Siderophore Production by Cyanobacteria, J. Phycol. 24, 566-571. 

S is the ambient concentration of available metal, kL is the rate constant for the uptake reaction in which the metal combines with a transport ligand, whose abundance per cell is given by LT. Having drawn attention to the likelihood that the Fe-transport molecules of eukaryotic algae are membrane bound siderophores, like those of cyanobacteria, Morel etal. conclude that there is ... 

Iron is a constituent of a number of cellular compounds in cyanobacteria, including several components of the photosynthetic apparatus, and growth can be limited by low concentrations of available iron in the medium. We report here studies of iron-limited growth and siderophore production in the heterocyst-containing filamentous cyanobacterium Anabaena variabills. 

The cyanobacterial strain used was obtained from CCAP as Anabaena flos-aquae 1403/13a and is the same as Anabaena variabilis ATCC 29413. It was grown at 32-35 C under continuous illumination in a nitrogen-free medium (BG-llo) or an iron-limited variant of BG-llo from which citrate and EDTA were omitted. Iron-limited medium contained either 0.2 pM or 2.0 liM added FeCla. Fructose (10 mM) was added as carbon source. Growth kinetics were measured using 50 ml volumes of culture in 100 ml shaken flasks. Cyanobacteria for the purification of siderophore were grown in 300 ml batches in 1000 ml flasks. Growth was routinely measured by apparent absorbance at 550 nm and converted to cell carbon using a separate calibration curve for each iron concentration. 

Structure of marine cyanobacterial siderophores has not been reported until recently. Synechobactins (21) are the first structurally elucidated siderophores from marine cyanobacteria [55] and are related to schizokinen isolated from freshwater cyanobacteria [56]. Synechobactins were isolated from the supernatant of the coastal marine cyanobacterium Synechococcus sp. Although they are not heterocycles, they are included in this review because... 

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