In anaerobic digestion, we deprive biodegradable material of oxygen and use microorganisms to convert the biodegradable materials to end products, including biogas. Anaerobic digestion occurs naturally in nature and in places like landfills where bacteria break down organic matter—such as manure—without oxygen. As the bacteria break down the organic matter, they generate biogas. Biogas, containing 50-70 percent methane, can then be processed into transportation fuels and renewable energies or combusted to generate heat and electricity.