CAREER: The role of quorum sensing in a methane-oxidizing bacterial community

University Of Utah, Salt Lake City UT

Investigators

Abstract

Bacterial communities perform many important processes on Earth, from cycling carbon to sequestering and degrading pollutants. However, the molecular details of how the bacteria in these communities interact with each other and their environment to perform these functions are still not understood. This project will use state-of-the-art mass spectrometry and genomic methods to determine how bacteria in a community that consumes the greenhouse gas methane interact using chemical signaling molecules, and how these interactions influence the rate of methane consumption. The research results will help in understanding the structure and function of important bacterial communities, to allow for modeling and prediction of these processes in the future. To increase career awareness in biochemistry amongst students at the University of Utah, the project will use a multicomponent approach entitled Biochemists: Behind the Scene which integrates with and enhances existing initiatives at the University of Utah. This approach will introduce students to the people and processes behind biochemistry research, to make this field more relatable and help these students develop a science identity and sense of self-efficacy. Aerobic methane-oxidizing bacterial communities sequester this potent greenhouse gas by distributing methane-derived carbon among direct oxidizers and bacteria that do not oxidize methane themselves. These organisms are therefore an important part of the carbon cycle. However, the molecular details that govern interactions in these ecologically critical consortia are still not understood. Many bacteria use quorum sensing signals to regulate group behaviors in bacterial communities. While the role of quorum sensing has been studied in many individual species, much less work has been done on its role in whole communities that resemble those found in natural environments. This project will determine the role of quorum sensing in a model methane-oxidizing bacterial community. Quorum sensing signals present in the community will be identified using previously established quorum sensing signal identification methodologies, including inverse stable isotopic labeling, to determine which community members can produce these signals. A combination of untargeted metabolomics, metagenomics, and metatranscriptomics will be used to identify these signals and the genes they regulate in the model community, with complementary mechanistic studies in bacterial isolates and simplified synthetic communities. This work will provide a mechanistic understanding of how quorum sensing governs the structure and function of this system. This work will also characterize new quorum sensing signals and link regulated genes to their phenotypes, which will enable future predictions of molecular interactions in this and other environmentally important microbial communities. 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.