Mechanisms of Bacterial Competition
Our laboratory studies bacterial competition. Bacteria form communities that inhabit environments as distinctive as the human body and a desert soil. To thrive in varied environments, bacteria evolved dynamic mechanisms that promote their survival among competitor species. To understand mechanisms of competitive fitness, we use model systems that expose the functions bacteria require to adapt to competitors. For instance, we culture different species together and observe changes in patterns of growth and metabolism as evidence of competitive interaction. We then explore the biological mechanisms responsible for the changes we observe. Using this approach, we have discovered new ways that metabolites and enzymes support competitive fitness. As an example, we recently discovered that Bacillus subtilis detects small amounts of some antibiotics produced by different species of Streptomyces. When detected, Bacillus subtilis responds to the antibiotics by mobilizing a population of cells in a counter attack. These studies enable us to identify new metabolites that bacteria use to interfere with other species and to determine new mechanisms that bacteria employ to counter competitive challenge. Our discoveries expand our knowledge of the physiological demands for bacteria living among competitors and advance our understanding of how competition influences bacterial communities.