The Influence of Flow on Capture and Growth of Rod-like E. coli on Cationic and Hydrophobic Surfaces*

Living organisms usually utilize chemical or biomolecular signals that often transmit slowly. However, bacterial cells can respond very quickly, yielding interesting opportunities for interfacing with bacteria. In this work, we study the bacterial sense of surfaces to establish the new research area of sensory-based bacterial communication. The focus is on how E. coli react to different surfaces such as cationic surface, hydrophobic surface, and bare glass. Propidium iodide and HCC-amino-D-alanine is used to check the viability and growth of E. coli on surfaces. Employing high resolution microscopy with a flow cell system, we investigate the adsorption rate, vertical orientation, and horizontal angular distribution of E. coli on three surfaces. We find orientation changes of the bacteria in the high shear flow and the significant differences were found between different type of surfaces.