posted on 2019-08-22, 21:13authored byDivya Iyer, Alexey V. Gulyuk, Pramod Reddy, Ronny Kirste, Ramon Collazo, Dennis R. LaJeunesse, Albena Ivanisevic
Bacterial
behavior is often controlled by structural and composition
elements of their cell wall. Using genetic mutant strains that change
specific aspects of their surface structure, we modified bacterial
behavior in response to semiconductor surfaces. We monitored the adhesion,
membrane potential, and catalase activity of the Gram-negative bacterium Escherichia coli (E. coli) that were mutant
for genes encoding components of their surface architecture, specifically
flagella, fimbriae, curli, and components of the lipopolysaccharide
membrane, while on gallium nitride (GaN) surfaces with different surface
potentials. The bacteria and the semiconductor surface properties
were recorded prior to the biofilm studies. The data from the materials
and bioassays characterization supports the notion that alteration
of the surface structure of the E. coli bacterium
resulted in changes to bacterium behavior on the GaN medium. Loss
of specific surface structure on the E. coli bacterium
reduced its sensitivity to the semiconductor interfaces, while other
mutations increase bacterial adhesion when compared to the wild-type
control E. coli bacteria. These results demonstrate
that bacterial behavior and responses to GaN semiconductor materials
can be controlled genetically and can be utilized to tune the fate
of living bacteria on GaN surfaces.