Methanosarcina is a genus of archaea that are a major group of methanogens, producing methane as a metabolic byproduct. They are found in anaerobic environments like wetlands and the guts of animals. Genomic DNA from Methanosarcina is used to study the genetic and metabolic pathways of methanogenesis. It's a key resource for research on biofuels, climate change, and anaerobic digestion.