Diatom silicon biomineralization as an inspirational source of new approaches to silica production

Structural change of the frustule of diatom by thermal treatment

“…Diatom has an external skeleton called a frustule, which is composed of hydrous amorphous silica formed by precipitation of silica within silica deposition of vesicle during cell division (Vrieling et al 1999a(Vrieling et al , 1999b. The system of bio-silicification in the frustule is related to silaffins which can precipitate of silica and generate silica nanospheres (Kröger et al 1999).…”

Morphological observation of Epithemia ocellata (Ehr.) Kütz. (Bacillariophyceae) from China

“…The valve morphogenesis has been studied mainly by ultrastructural analysis (Vrieling and Beelen, 1999). Each half (theca) consists a valve and a girdle (Kroger and Wetherbee, 2000).…”

“…Each half (theca) consists a valve and a girdle (Kroger and Wetherbee, 2000). During diatom replication, the two halves of the frustule separate, and new valves and girdles are synthesized intracellularly with specialized organelles (silicadeposition vesicles, or SDV) (Parkinson and Gordon, 1999;Vrieling and Beelen, 1999). An ontogenetic approach can facilitate interpretation of valve ultrastructure and reveal how contrasting the features broken hymens along the face of vale (double arrowhead).…”

“…Prior to cell division each of two daughter cells within the mother cell develops a new hypovalve and girdle bands in a special cellular compartment -the silicon deposition vesicle (SDV). The final macro-morphology of the siliceous parts, especially the so-called raphe, ribs and areolae, etc., most probably reflects the cellular, genetically-driven molding activity to shape the SDV during silica polymerization (Vrieling and Beelen, 1999). Epithemia belongs to biraphid diatom genera.…”

Calculation of 29Si NMR shifts of silicate complexes with carbohydrates, amino acids, and muhicarboxylic acids: potential role in biological silica utilization

“…The slower rate would, presumably, allow greater control on the shapes and sizes of the mesoporous silica precipitated. The same strategy is followed in sol-gel and biomimetic silica synthesis methods (e.g., Birchall, 1989;Morse, 1999;Tacke et al, 1999;Vrieling et al, 1999b). Furthermore, it has been known since the early to mid-1990s that hyper-coordinated silicate-organic complexes are highly reactive species occurring as transient intermediate species such as intermediates or as activated complexes, in both the motherliquor and in the freshly precipitated solid (Belot et al, 1990;Laine et al, 1991;Herreros et al, 1994a,b).…”