Bacterial biofilms

This chapter reviews our understanding about bacterial biofilms, the science and technology involved in their formation, and the roles biofilm-associated microbial communities play in maintaining and improving the ecological health of freshwater ecosystems. In aquatic ecosystems biofilms colonize the different compartments (sand, rocks, leaves) and play a key role in the uptake of organic and inorganic nutrients. The perception of biofilms has changed considerably because of the technological developments and the use of different culturing methods (static microtiter plate method, tube biofilm, colony biofilm, peg lids, and rotating biological cylinders), biochemical methods, and molecular characterization (confocal laser scanning microscopy, scanning electron microscopy, nuclear magnetic resonance) to elucidate the biofilm diversity. The chapter aims to give a detailed knowledge on the availability of biofilms in freshwater lakes, their formation, diversity, and their relationship with ecosystem functioning. It goes on discussing briefly the nitrogen fixing microorganisms present in freshwater lakes. The chapter concludes with a review of the recent advances in bioremediation, with particular reference to the role of microbial biofilms, the emerging technologies such as genetic engineering technologies that are employed to improve bioremediation effectiveness, both in laboratory and in field applications.