![The multiple roles of methanogens in the modern-day carbon cycle. Processes shown in red contribute to greenhouse gas production. Part of the methane is removed through microbial methane oxidation (A)MO and photochemical reactions, where e is a generic electron donor (e.g., sulfate, nitrate, arsenate, iron, or manganese) that is reduced to eH. Processes depicted in green sequester CO2, storing it long term as carbonates. Dashed arrows show the potential contribution of methanogen metabolism in the precipitation of carbonate minerals, which contributes to the storage of carbon in the lithosphere. The metabolic activity of methanogens may locally alter pH (a part of energy generation) and produce copious amounts of EPS (seen as a veil surrounding the cells in the microphotograph (yellow arrow)). These EPS bind cations (e.g., Ca, Mg) and act as a nucleation site, while elevated pH enhances the carbonate precipitation in microbial mats [228]. This contribution by methanogens may ultimately impact the production of microbialites [154]. Solid arrows show known effects; dashed lines indicate hypothetical effects. -- Geosciences via x-mol.net](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/05/Methanogens-Through-Time.png?resize=1200%2C716&ssl=1)
Methanogens, or methanogenic archaea (MA), are among the most ancient and widely distributed microorganisms, characterized by a unique metabolism that generates methane (CH4) as the terminal product of anaerobic respiration.
South Africa is home to some of the oldest evidence of life on Earth, contained in rocky, often layered outcroppings called microbialites. Like coral reefs, these complex “living rocks” are […]
Northern Foothills of Victoria Land, Antarctica contains numerous hydrological formations, ranging from small surface streams and ponds fed by glacial or snow meltwater to permafrost lakes containing briny pockets.
By Emma Caton — In the depths of remote Antarctic lakes, communities of microorganisms are thriving where few life forms can survive.
Three strains of thermophilic green sulfur bacteria (GSB) are known; all are from microbial mats in hot springs in Rotorua, New Zealand (NZ) and belong to the species Chlorobaculum tepidum.
Guaymas Basin is a young marginal rift basin in the Gulf of California characterized by active seafloor spreading, rapid deposition of organic-rich sediments, and steep geothermal gradients where sedimentary organic […]
This stromatolite formed about 2.7 billion years ago and was collected from an ancient lake environment preserved in the Tumbiana Formation, a succession of clastic and carbonate rocks outcropping along […]
Virtually all oxygen on Earth was and is produced by photosynthesis, which was invented by tiny organisms, the cyanobacteria, when our planet was still a rather uninhabitable place.
Researchers have identified the first cold-adaptation proteins found in microbial mats from Lake Joyce, a perennially ice-covered lake in Antarctica.
Photosynthetic microbial mats forming large conical structures up to half a meter tall have been discovered by astrobiologists in Lake Untersee, Antarctica. This research is described in an article in […]
