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Updated: Jul 14, 2026
08:04
Preparation of Functional Silica Using a Bioinspired Method
Published on: August 1, 2018
Salinity-dependent diatom biosilicification implies an important role of external ionic strength
Engel G Vrieling1, Qianyao Sun, Mingwen Tian
1Groningen Biomolecular Sciences and Biotechnology Institute, Center for Ecological and Evolutionary Studies, University of Groningen, NL-9750 AA Haren, The Netherlands. e.g.vrieling@rug.nl
Summary
External ionic strength significantly impacts diatom biosilica formation. Lower salinity results in denser diatom shells with reduced surface area and pore size, affecting nanostructure.
Area of Science:
- Marine biology
- Biomineralization
- Nanotechnology
Background:
- Diatoms are unicellular algae that produce intricate silica shells called frustules.
- Biosilica formation is influenced by various environmental factors, including ionic conditions.
- Understanding these factors is crucial for controlling silica precipitation and diatom growth.
Purpose of the Study:
- To investigate the effect of external ionic strength on the nanostructural properties of diatom biosilica.
- To determine how salinity influences the specific surface area, fractal dimensions, and mesopore size of diatom frustules.
- To elucidate the mechanisms underlying salinity-induced changes in diatom silica deposition.
Main Methods:
- Culturing two marine diatom species (Thalassiosira punctigera and Thalassiosira weissflogii) at distinct salinities.
- Employing physicochemical methods to analyze the nanostructural changes in the biosilica.
- Comparing specific surface area, fractal dimensions, and mesopore characteristics of biosilica from different salinity conditions.
Main Results:
- Lower salinity conditions led to a decrease in specific surface area, fractal dimensions, and mesopore size of the diatom biosilica.
- Biosilica formed at lower salinities exhibited increased density.
- These changes suggest particle aggregation within the silica deposition vesicle at reduced external ionic strength.
Conclusions:
- External ionic strength plays a critical role in regulating diatom biosilica nanostructure.
- The findings suggest simultaneous uptake of silicic acid and other ions, potentially via (macro)pinocytosis.
- This mechanism is more plausible than intracellular transport of silica precursors for frustule formation.
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