MP Board · Class 12 · Biology · Microbes in Human WelfareMethanogens are anaerobic bacteria that grow on cellulosic material and produce large amounts of methane along with carbon dioxide and hydrogen. These bacteria are collectively known as methanogens, and a common example is Methanobacterium. They play a crucial role in the generation of biogas, which is commonly known as gobar gas. In a biogas plant, the anaerobic digestion of cattle dung and other organic wastes by these bacteria produces a combustible gas mixture rich in methane, which is used for cooking and lighting in rural areas. Naturally in nature, methanogens are found in the rumen of cattle, where they help in the breakdown of cellulose present in the plant-based food eaten by the cattle, and their excreta (dung) is therefore rich in these bacteria, making it an ideal raw material for biogas production.