Silica (basically glass) is one of the most useful and abundant materials we encounter in our everyday life. It is widespread in natural settings and in traditional industrial applications. Maybe more importantly it is now being a major player in advanced nanomaterial developments for technology. A major goal of material engineering is to control the nanoscale shapes and properties of this inorganic solid. However, this is very difficult to achieve as conventional synthesis involves harsh chemical conditions and lead to simple silica structures. On the other hand, very simple organisms have evolved a magnificent ability to form silicified structures with tightly controlled properties. One such group is diatoms, the most abundant unicellular algae in the oceans, which form an intricate cell wall that is made of silica via a physiological process. The goal of BioSilica project is to achieve a mechanistic understanding of diatom silicification to the level that it will enable us to engineer this process to yield silica product with desirable products. In the long run we envision that it will be possible to genetically encode the needed silica properties for a specific application into the organism DNA, which then will allow to ‘grow’ such nanomaterials using only sunlight and seawater. What can be more ‘green’ than that?!
After concluding the experimental section of the project, we can conclude that we have now more detailed understanding about the mechanism of diatom silicification. Specifically, we have come to know that the major controller of the process is the engulfing membrane that is regulating the transport for mineral formation, the morphogenesis of the structure, and its exocytosis to the cell surface. This knowledge will enable future work to target specific machineries inside the cells for intelligent design of the silica elements. A persistent challenge is the availability of genetic tools, which are still rudimentary and limit the scope of such engineering avenues.
