Methanogens are a unique group of strictly anaerobic archaea that are more metabolically diverse than previously thought. Traditionally, it was thought that methanogens could only generate methane by coupling the oxidation of products formed by fermentative bacteria with the reduction of CO₂. However, it has recently been observed that many methanogens can also use electrons extruded from metal-respiring bacteria, biocathodes, or insoluble electron shuttles as energy sources. Methanogens are found in both human-made and natural environments and are responsible for the production of ∼71% of the global atmospheric methane. Their habitats range from the human digestive tract to hydrothermal vents. Although biologically produced methane can negatively impact the environment if released into the atmosphere, when captured, it can serve as a potent fuel source. The anaerobic digestion of wastes such as animal manure, human sewage, or food waste produces biogas which is composed of ∼60% methane. Methane from biogas can be cleaned to yield purified methane (biomethane) that can be readily incorporated into natural gas pipelines making it a promising renewable energy source. Conventional anaerobic digestion is limited by long retention times, low organics removal efficiencies, and low biogas production rates. Therefore, many studies are being conducted to improve the anaerobic digestion process. Researchers have found that addition of conductive materials and/or electrically active cathodes to anaerobic digesters can stimulate the digestion process and increase methane content of biogas. It is hoped that optimization of anaerobic digesters will make biogas more readily accessible to the average person.

产甲烷菌是一组独特的严格厌氧古细菌，其代谢多样性比以前认为的要高。传统上，人们认为产甲烷菌只能通过将发酵菌形成的产物的氧化与CO ₂的还原耦合来产生甲烷。。但是，最近发现，许多产甲烷菌也可以使用从呼吸金属的细菌，生物阴极或不溶性电子穿梭中挤出的电子作为能源。产甲烷的甲烷存在于人造环境和自然环境中，约占全球大气甲烷产量的71％。它们的栖息地范围从人类的消化道到热液喷口。尽管生物产生的甲烷如果释放到大气中会给环境带来负面影响，但是当被捕获时，它可以作为有效的燃料来源。粪便（如动物粪便，人类污水或食物残渣）的厌氧消化产生的沼气为由约60％的甲烷组成。可以净化沼气中的甲烷以产生纯净的甲烷（生物甲烷），可以将其轻松地掺入天然气管道中，从而成为有前途的可再生能源。常规的厌氧消化受到保留时间长，有机物去除效率低和沼气生产率低的限制。因此，正在进行许多研究以改善厌氧消化过程。研究人员发现，向厌氧消化池添加导电材料和/或电活性阴极可刺激消化过程并增加沼气的甲烷含量。希望优化厌氧消化池将使普通人更容易获得沼气。