POLY 531 Effect of flow on the structure of biological and synthetic minerals

Diatoms have ornate biosilica frustules that are species-specific and are formed under genetic control. We have observed interesting changes in the shape of diatoms both in laboratory cultures and in nature when they are exposed to different environmental conditions such as flow rate or UV radiation. It has been recently discovered that biosilica formation is facilitated by a variety of biological organic molecules. For example, it is proposed that silaffin proteins and ‘small' propylamines are involved in diatom biosilicification. In order to us help to understand the role(s) of organic biomolecules in vivo, model in vitro studies have been carried out where synthetic and biological molecules have been studied for their effects on silica formation. The study of silica formation using R5 peptide which is derived from silaffin proteins is one such example. An interesting observation is that flow can change the structure of both synthetic and biological minerals.