Iron incorporation in biosilica of the marine diatom Stephanopyxis turris: dispersed or clustered?
Iron incorporation into diatom biosilica was investigated for the species Stephanopyxis turris . It is known that several “foreign” elements (e.g., germanium, titanium, aluminum, zinc, iron) can be incorporated into the siliceous cell walls of diatoms in addition to silicon dioxide (SiO 2 ). In or...
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Published in | Biometals Vol. 30; no. 1; pp. 71 - 82 |
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Main Authors | , , , , , |
Format | Journal Article |
Language | English Dutch |
Published |
Dordrecht
Springer Netherlands
01.02.2017
Springer Nature B.V |
Subjects | |
Online Access | Get full text |
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Summary: | Iron incorporation into diatom biosilica was investigated for the species
Stephanopyxis
turris
. It is known that several “foreign” elements (e.g., germanium, titanium, aluminum, zinc, iron) can be incorporated into the siliceous cell walls of diatoms in addition to silicon dioxide (SiO
2
). In order to examine the amount and form of iron incorporation, the iron content in the growth medium was varied during cultivation. Fe:Si ratios of isolated cell walls were measured by ICP-OES. SEM studies were performed to examine of a possible influence of excess iron during diatom growth upon cell wall formation. The chemical state of biosilica-attached iron was characterized by a combination of infrared,
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Si MAS NMR, and EPR spectroscopy. For comparison, synthetic silicagels of variable iron content were studied. Our investigations show that iron incorporation in biosilica is limited. More than 95% of biosilica-attached iron is found in the form of iron clusters/nanoparticles. In contrast, iron is preferentially dispersedly incorporated within the silica framework in synthetic silicagels leading to Si–O–Fe bond formation. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0966-0844 1572-8773 |
DOI: | 10.1007/s10534-016-9987-4 |