Abstract
Microorganisms tend to form biofilms on biotic and/or abiotic surfaces, which is a com plicated process consisting of two phases: an initial adhesion phase and the subsequent biofilm development phase. Many kinds of bacteria have filamentous cell appendages, which are several to tens nanometers in diameter, such as flagella and pili. These bacterionanofibers have been shown to function as adhesins. We have been studying the mechanisms of microbial adhesion and biofilm formation and their application to bioprocesses. In this article, our recent results are briefly reviewed with future direction of the study. In application of biofilms to waste water treatment, three successful examples are introduced; they are construction of functional biofilms for oil degradation as a new concept of “bottom-up biofilms”, biological prevention of biofouling in membrane bioreactors, and the mechanism of high capacity of carbon fiber for adsorbing sludge and microorganisms. In the topic about bacterionanofibers, a new fibrous adhesin designated AtaA from the highly adhesive bacterium Acinetobacter sp. Tol 5 is introduced in terms of its structure and function. It can be utilized to direct immobilization of microbial cells. An example of production of a chemical using the immobilized cells is demonstrated.
