Intraspecies competition mechanisms in Bacillus subtilis

Microbial consortia influence our environment in countless ways. These multispecies communities have a direct impact on bioremediation cycles, our health, and food production processes. The composition and function of these pervasive microbial ecosystems is continually modulated by the complex and dynamic interactions of the resident microorganisms. Advanced knowledge of the mechanisms that govern microbial interactions, both competitive and cooperative, will enhance our ability to engineer synthetic microbial consortia for specific purposes and to manipulate existing ecosystems to enhance their functionality.

Bacillus subtilis is a Gram-positive bacterium that lives in a wide range of environments from concrete fissures and intestinal tracts to in soil and on the surfaces of plant seeds and roots. Alongside other Bacillus species, B. subtilis is of significant economic importance and is used as a bioactive agent with a variety of commercial uses. The areas that Bacillus spores are used in include plant growth promoting agents, probiotics for animal and human use (capsule and food/drink additives), insect control measures, and in microbial-based cleaning products.

For a live biologic, such as B. subtilis, to have the desired impact, the introduced bacteria must first integrate into the established ecosystem to which it is being added. One of the critical steps of integration into an ecosystem is opening space in the niche already occupied by resident strains of the same species. This integration process requires intraspecies interactions. The PhD project will uncover the ways B. subtilis can achieve dominance over competing isolates. There will be a focus on the molecular nature of the intraspecies interactions between specific isolates with full genome sequences. The student appointed will become trained in molecular genetics and will apply microfluidic based imaging to examine the mode of intraspecies interaction. The student will also be encouraged to develop skills in communication and public engagement with research.