A self-propagating system for Ge incorporation into nanostructured silicaf

摘要

Technologically-relevant levels of Ge can be incorporated into cell wall silica of the diatom Thalassiosira pseudonana with no aberration in structure at low levels, whereas higher levels alter structure.rnThe eukaryotic algae known as diatoms populate a broad range of oceanic and freshwater environments. A characteristic feature of these single-celled organisms is a rigid, three-dimensionally (3-D) structured cell wall (the frustule) composed largely, but not entirely, of amorphous nanostructured silica (Fig.1). Estimates of the number of diatom species are in the tens of thousands, each having a unique silica structure. Frustule morphology is genetically encoded and, within a given species, is reproduced with fidelity from generation to generation. Diatoms are amenable to being cultured in a laboratory setting, as they are typically photosynthetic and require minimal supplementation. The relatively rapid growth rate of diatoms allows high cell densities to be achieved in cultures, yielding large quantities of biogenic silica for experimental investigations.