This project will identify and characterize spatially coupled biochemical processes in methanogenic archaea, microbes that have the unique capability to grow by synthesizing the high-energy fuel methane. 60-99% of the carbon that methanogenic archaea consume is converted to methane gas that can be used to produce heat, electricity, transportation or rocket fuel with clean water as a byproduct. Molecular, biochemical, and computational techniques will be used to investigate how enzymes used by methanogenic archaea work together to efficiently convert low-energy growth substrates to high-energy methane gas. By identifying and characterizing enzyme interactions within cells, the research will reveal how methanogenic archaea control the flow of carbon and electrons to convert abundant, low-energy substrates such as acetate and methanol into methane gas. This knowledge will lead to a better understanding of how methanogenic archaea function in a variety of natural environments, such as in marine, freshwater, and terrestrial subsurface or in human and animal digestive tracts. This work generates knowledge with translational potential that could be used to increase the supply of renewable methane fuel to meet society’s energy needs. This project also supports recruitment and education of undergraduate, graduate, and postdoctoral trainees in anaerobic microbial physiology, molecular biology, and redox biochemistry in preparation for careers in industry, academia, and government to su