Emergent properties in microbes
Cells, to biofilms, colonies and swarms
How do macroscopic structures and behaviors arise from millions of microscopic cells?
From an early age, we learn that large organisms like animals develop from cells to tissues, tissues to organs, organ systems to organisms, and ultimately, organisms interact within ecosystems. This basic concept in biology is remarkable: with each transition along these levels of biological organization, the collective activity of the system gains "emergent properties" that cannot be achieved by the individual parts.
Although microbes like bacteria and archaea are traditionally thought of as unicellular organisms, similar levels of biological organization are central to the biology of the microbial world. While microbes sometimes exist as single cells in natural environments, much more often they live within communities of cells, including structured communities called biofilms. Within a biofilm, thousands or millions of cells, from a single species, or of many different species, live within one viscous extracellular matrix. The matrix is produced by the cells themselves and is similar in principle to the matrix that holds animal cells together within a tissue. Virtually every surface on Earth is covered by biofilms. It's an ecosystem that, at the level of the microbial world, is something like a dense and diverse rainforest.
I am interested in the basic biology and fundamental principles of multicellular and emergent phenomena in microbes. Specifically, I am developing new ways to image microbial structures, developmental processes and behaviors. I work with a variety of species with multicellular lifestyles and complex behaviors, including Bacillus subtilis, Pseudomonas aeruginosa, Myxococcus xanthus and Actintobacteria.
Above animation: A developing Pseudomonas aeruginosa biofilm