CBE Research Area:

Cell-Cell Communication

Cell-cell communication in bacteria is associated with the accumulation of signal molecules that co-regulate gene transcription. These signal molecules act at the global level and, consequently, a wide variety of cellular functions are influenced. Because many cell activities are involved, this research area actually bridges all other research areas in the Center for Biofilm Engineering.

Goals

• Understand how cell-cell communication affects biofilm structure and behavior.

• Employ signal molecule analogs to manipulate or facilitate biofilm formation or removal.

• Investigate how these signal molecules interact with other signaling systems in the bacterial cell.

Highlights

• Biofilm structural heterogeneity is dramatically influenced by quorum sensing circuitry. Using defined mutants that are defective in the synthesis of key signaling metabolites, biofilm architecture has been shown to change dramatically; channels and plumes normally observed in wild-type biofilms are replaced by rather homogeneous stacking of cells.

• Our analyses using chemical staining techniques with planktonic cells and biofilms, and biochemical characterization of extracellular polysaccharides, indicate that extracellular polysaccharide is significantly suppressed in quorum sensing mutants. Reduced polysaccharide appears linked to lack of structural heterogeneity in biofilms formed by these mutants.

• A treatment system for removal of established biofilms was elucidated using purified signaling molecules. A patent for this technology is currently pending.