Mark Geoghegan, Johanna S. Andrews, Catherine A. Biggs, Kevin E. Eboigbodin, David R. Elliott, Stephen Rolfe, Julie Scholes, Jesús J. Ojeda, Maria E. Romero-González, Robert G. J. Edyvean, Linda Swanson, Ramune Rutkaite, Rasika Fernando, Yu Pen, Zhenyu Zhang and Steven A. Banwart

Faraday Discussions., 2008, DOI: 10.1039/b717046g

The attachment of microbial cells to solid substrata is a primary ecological strategy for the survival of species and the development of specific activity and function within communities. An hypothesis arising from a biological sciences perspective may be stated as follows:The attachment of microbes to interfaces is controlled by the macromolecular structure of the cell wall and the functional genes that are induced for its biological synthesis. Following logically from this is the view that diverse attached cell behaviour is mediated by the physical and chemical interactions of these macromolecules in the interfacial region and with other cells. This aspect can be reduced to its simplest form by treating physico-chemical interactions as colloidal forces acting between an isolated cell and a solid or pseudo solid substratum. These forces can be analysed by established methods rooted in DLVO (Derjaguin, Landau, Verwey and Overbeek) theory. Such a methodology provides little insight into what governs changes in the behaviour of the cell wall attached to surfaces, or indeed other cells. Nor does it shed any light on the expulsion of macromolecules that modify the interface such as formation of slime layers. These physical and chemical problems must be treated at the more fundamental level of the structure and behaviour of the individual components of the cell wall, for example biosurfactants and extracellular polysaccharides. This allows us to restate the above hypothesis in physical sciences terms:Cell attachment and related cell growth behaviour is mediated by macromolecular physics and chemistry in the interfacial environment. Ecological success depends on the genetic potential to favourably influence the interface through adaptation of the macromolecular structure.