Microbial Metropolis - A Microbial Biofilm Community

Microorganisms can form tightly bind communities such as biofilms. Many others include marine snow, anaerobic digester granules, the ginger beer plant, bacterial colonies, effluent treatment floc and food associated systems. Biofilm-associated cells can be differentiated from their suspended counterparts by generation of an extracellular polymeric substance (EPS) matrix, reduced growth rates, and the up and down regulation of specific genes. The solid-liquid interface between a surface and an aqueous medium (e. g. , water, blood etc. ) provides an ideal environment for the attachment and growth of microorganisms (Gillings et. al. , 2008). Attachment is a complex process regulated by diverse characteristics of the growth medium, substratum and cell surface. An established biofilm structure comprises microbial cells and EPS, has a defined architecture and provides an optimal environment for the exchange of genetic material between cells. (Sur, 2008). As the origins of EPS are complex, many factors could influence the production of EPS. In future the roles of EPS components become known, identification of such key factors would then be very useful to manipulate the EPS compositions and contents in microbial aggregates and thus to improve the functions of microbial aggregates, e. g. , flocculation, settlement and dewatering abilities.