Silicification by Diatoms

Apposition of silica lamellae during growth of spicules in the demosponge Suberites domuncula: Biological/biochemical studies and chemical/biomimetical confirmation

“…Therefore, we propose that the vesicles are filled with silicic acid at an undetermined determination. Hence we adopt the view proposed by Chisholm et al (1978) and Sullivan (1986) showing the accumulation of silicic acid in the silica deposition vesicles.…”

Diatom teratological forms and environmental alterations: a review

“…Before frustule deposition, uptake kinetics indicate affinity and low capacity for Si uptake: in this phase, the silicic acid transporters are probably located only in the plasma membrane. During silicification, the uptake kinetics show high affinity and high capacity for Si uptake, due to an increase in the number of silicic acid transporters located in silicon transport and deposition vesicles as well as in the plasma membrane (Sullivan, 1977(Sullivan, , 1986Sullivan & Volcani, 1981;Martin-Jézéquel et al, 2000). Once inside the cell, unpolymerized silicic acid is maintained at high intracellular levels by means of silicon-binding components or ionophoretic activities (Bhattacharyya & Volcani, 1980;Martin-Jézéquel et al, 2000).…”

Si and C interactions in the world ocean: Importance of ecological processes and implications for the role of diatoms in the biological pump

“…Consequently, silicic acid uptake takes place in the dark as well as in the light [Chisholm, 1981;Martin-Jézéquel et al, 2000]. Silicon uptake and deposition appear to be mainly associated with the formation of new siliceous valves during the G2 and M phase just prior to cell division [Sullivan, 1986;Hildebrand, 2000;Claquin and Martin-Jézéquel, 2005], although some species can assimilate silicon during an earlier phase of the cell cycle and stock it [Chisholm et al, 1978;Brzezinski and Conley, 1994]. A part of silicon is incorporated in girdle bands; these bands allow the increase of the cell volume during the cell life and may contain, in some species, a large amount of Si [Round et al, 1990].…”