Elucidating, understanding, and leveraging 'covert' metabolic interactions in synthetic microbial communities.

About This Grant

Microbial communities are crucial for the survival of many organisms, including numerous plants and humans, and they are crucial for the health of ecosystems all over the planet. Efforts to engineer microbial communities for specific health, agriculture and industrial functions have often failed, leading to the novel, broadly applicable strategy analyzed in this project. This project will reveal valuable and previously unknown microbial interactions, and this knowledge may be leveraged for “build-to-order” microbial communities that enhance activities such as food production and production of high-value chemicals. This project also seeks to engage students across the K-12 and undergraduate pipeline through meaningful, interactive experiences designed to kindle their interest in STEM and fuel their enthusiasm for STEM education and careers. Research training opportunities will be provided for several undergraduate students. Outreach to the broader community, meanwhile, will be achieved by developing hands-on demonstrations as part of Arizona State University's annual Open Door event. Here, local K-12 students and their families will be engaged using real-world examples that highlight the critical roles that microbial communities play in processes of importance to human health, the environment, and industrial biotechnology. Since past studies regarding metabolic interactions within synthetic microbial communities have focused heavily upon obligate interactions that are essential to community growth and survival, little remains known regarding non-obligate metabolic interactions, including with respect to their nature and importance. This concept will be explored for pairs of prototrophic bacteria, including different strains of Escherichia coli. A novel method based on non-canonical amino acid tagging will be developed to isolate and analyze strain-specific total protein samples from mixed cultures, thereby revealing exchanged metabolites. These insights will be used to model central metabolism flux throughout each strain, thereby revealing potential metabolic differences during monoculture versus coculture growth. Different environmental stressors as well as adaptive laboratory evolution will be used to gain new insights regarding metabolic and evolutionary strategies for improving community growth and robustness. Overall insights gained here will ultimately translate into more holistic design strategies and ‘synthetic ecology’ approaches for engineering synthetic microbial communities with enhanced performance in bioproduction environments. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.