Microbial communities govern the nutrient cycles, integrity of solid surfaces, and health of other organisms in essentially every habitat on Earth. To affect these processes towards improving the health of animals, plants, or the planet itself, it is necessary to understand what makes communities resistant and also susceptible to change. For example, soil communities influence crop health and global climate, and yet little is known about the principles governing stability and change in this habitat. This project will enable an investigation of the nature of community robustness - the resistance to, and recovery from disturbance. One especially interesting aspect of robustness is invasion. Towards understanding the traits that make bacteria successful community invaders, and conversely, the traits of communities that enable them to exclude invaders, a simple model system is required, in which variables can be controlled and genetic analysis can be applied. This project focuses on the microbial community associated with sand grains in soil for several reasons, including the relative uniformity of sand particles, the disaggregated nature of sand (compared with other soil components), the aerobic nature of sand-associated communities, exposure of sand communities to invaders, and the ease of manipulation of sand grains as experimental units. Thus, laying the groundwork for identifying genes and metabolites that influence invasion and exclusion, a model community, together with appropriate bacterial invaders, will be designed and developed.
Broader Impacts: This project will provide research opportunities for undergraduates. A valued resource that will be relied upon to increase participation of ethnically diverse students in the project is the POSSE Program. This is a national program that recruits outstanding high school students to attend college as a cohort. POSSE students have a remarkably high graduation rate and they are truly exceptional scholars. This project will provide summer research experiences at Yale for POSSE students from other institutions, to be mentored by individuals trained in principles and practices of successful mentoring.
