NSF Award
2426384
Microorganisms can turn organic waste into biogas, a renewable alternative to petroleum-derived natural gas. Biogas production is carried out by a microbial community consisting of organic-consuming bacteria and biogas-producing microorganisms known as methanogens. These microorganisms work together in a very complicated network of interactions, which makes the overall process of biogas production vulnerable to changes in the environment. The goal of this project is to improve biogas production by creating a special community of microorganisms that convert waste into biogas more efficiently by feeding on electricity. Research has shown that some organic-consuming and biogas-producing microorganisms can use electricity as their energy source to grow. Based on these studies, an innovative method is proposed for building the microbial community by continuously switching the direction of electricity. When the direction of electricity is switched, both the organic-consuming and biogas-producing microorganisms can gain energy to grow. As a result, the community can be made more resilient to changes in the environment, and biogas can be produced at a high rate. Successful completion of this research will improve our understanding of how these microorganisms work in nature and holds promise as a source of cleaner and cheaper renewable biogas energy. Additional benefits to society result from educational opportunities for high school and college students from underserved groups to diversify and enhance the Nation’s STEM workforce.<br/><br/>Methanogenic microbial communities convert organic waste into methane biogas. Biogas production can be enhanced by building synthetic microbial communities capable of electro-methanogenesis. The goal of this project is to develop a novel approach to build electro-methanogenic communities as a model system to understand the mechanisms for microbial community assembly and extracellular electron uptake. The central hypothesis of this research is that electro-methanogenic communities can be readily assembled using alternating polarity. As the electrode potential is alternated, the electrode serves as an electron donor for electrotrophic methanogens as well as an electron acceptor for electroactive bacteria. Together, this process results in simultaneous selection of both populations. To test the central hypothesis, three interconnected research aims will be pursued to: i) build robust electro-methanogenic communities with alternating polarity, ii) quantify the contribution of different driving forces to community assembly, and iii) elucidate the metabolic pathways involved in extracellular electron uptake. Completion of this research will advance our understanding of the ecological role of electrotrophic microbial ecosystems, and potentially lead to new avenues for biogas production. Additional benefits of this project result from the training of high school, undergraduate, and graduate students from underserved groups by leveraging long-standing engagement between the research team and the Society of Women Engineers, the National Society of Black Engineers, and the Society of Hispanic Professional Engineers.<br/><br/>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.
