ChEBE Faculty Research
Nehal Abu-Lail, Ph.D.
Investigate the Relationship between Micro-scale and Macro-scale Bacterial Adhesion
Over the years, significant work has been done to investigate the process of bacterial adhesion to surfaces on macroscopic scale. However, when it comes to the single molecule approach of investigating the bacterial adhesion phenomena, a lot of questions remained unanswered. Although exploring bacterial adhesion on a single molecule levels opens a new avenue of understanding the fundamentals of bacterial adhesion to surfaces, a legitimate concern remains with respect to the validity and the scaling of the observations found at the microscopic level to the macroscopic level. Studying bacterial adhesion with AFM is an in vitro study that is always run at equilibrium and at simplified experimental conditions, giving the ability to exclude the effect of individual factors on adhesion. In reality, a bacterial adhesion is a dynamic process that occurs in a very complex environment. A relationship between bacterial adhesions at these two levels thus is a necessity. For example, when a portion of E. coli JM109 surface lipopolysaccharides was removed using EDTA treatment, the microscopic adhesion of the bacterium to a model surface of silicon nitride and the macroscopic adhesion of the bacterium to silica particles decreased dramatically.
The purpose of this part of my research is therefore to compare bacterial adhesion to similar surfaces at the microscopic and macroscopic level. Column transport experiments, shear flow experiments, and retention studies of bacteria will demonstrate the macroscopic scale experiments while the AFM studies will be the microscopic data.