The overall goal of the research is to understand quorum sensing, the cell-to-cell communication process that controls bacterial collective behaviors. The studies proposed here will explore quorum-sensing control of single-species and mixed-species biofilm formation and dispersal. Biofilms are surface-attached bacterial communities and they represent the predominant form of bacterial life on Earth. Bacterial biofilms are crucial for ecology, industry, and medicine. This work will advance the progress of science by revealing the mechanisms that provide these multicellular systems their resilience. These investigations could lead to synthetic strategies for controlling bacterial biofilm formation and dispersal, when biofilm formation negatively impacts the environment and human health. Students at all levels will be trained by working on this project. Efforts to promote diversity among science faculty and students will continue, as will outreach efforts to inform the public across the nation.
Biofilms are communities of cells adhered to surfaces. Biofilms represent the predominant form of bacterial life on Earth. Bacterial biofilms are crucial for ecology, industry, and medicine. This project will develop new imaging tools capable of resolving the growth dynamics and gene expression patterns of individual bacterial cells inside living biofilms. Gene regulation programs will be defined to understand what drives the spatial and temporal organization of biofilms and what mechanisms provide these multicellular systems their resilience. Other goals will be to discover how quorum sensing controls development of clonal and non-clonal biofilms, to reveal the molecular mechanisms driving transitions between the biofilm growth mode and the free-swimming state and to explore the ecological consequences to bacteria of transitioning into and out of biofilms. At the most general level, the research should move quorum-sensing studies out of the realm of shaken flask cultures and into new territory that includes realistic spatial and temporal features that more closely resemble the conditions under which bacteria normally live. Consequently, the results should reveal the principles underpinning the evolution and maintenance of expensive traits that are not essential under laboratory conditions, but are crucial and precisely regulated in nature. With this knowledge in hand, the field should be able to rapidly move forward to develop synthetic strategies to prevent or promote quorum sensing, to prevent or promote single-species and mixed-species biofilm formation, and to prevent or promote biofilm dispersal, as required.