作者： Sumedha Sharma^†, Yuly Andrea Jaimes-Lizcano^†, Ryan B. McLay^†, Patrick C. Cirino^†, and Jacinta C. Conrad^†‡

^†Department of Chemical and Biomolecular Engineering and ^‡Department of Petroleum Engineering, University of Houston, Houston, Texas 77204-4004, United States

 

摘要：We investigate the deposition and transient adhesion of Escherichia coli on alkyl and fluoroalkyl silanized glass surfaces of different carbon chain lengths. The rate at which bacteria deposit onto these surfaces decreases as the shear stress is increased from 3 to 67 mPa, but trends in the deposition rate across all surfaces cannot be predicted from extended DLVO calculations of the interaction potential. As the surface root-mean-square (rms) roughness increases, the deposition rate increases and the percentage of motile tethered cells decreases. Furthermore, on surfaces of root-mean-square roughness of less than 0.2 nm, bacteria exhibit adhesion, for which surface-associated cells linearly translate distances greater than approximay 1.5 times their average body length along the flow direction. E. coli bacteria with and without flagella exhibit adhesion, indicating that this behavior is not driven by these appendages. Cells that express fimbriae do not exhibit adhesion. These results suggest that even subnanoscale roughness can influence the deposition and transient adhesion of bacteria and imply that strategies to reduce frictional interactions by making cells or surfaces smoother may help to control the initial fouling of surfaces by E. coli bacteria.