I. In the Deepest of Places…
They’re possibly the oldest living beings on earth. They possess the power to create and destroy life-giving climates. They thrive in the deepest of places and most extreme conditions – submarine springs, volcanic vents, hot desert sands, glacial ice – as well as in marshlands, rice paddies, landfills, sewage plants, and in the guts of termites, ruminants, and humans. Discovering their existence forced scientists to restructure the phylogenetic tree and rethink the origins of life.
Their name is only just beginning to make it into our mainstream vocabulary. They are methanogens.
Methanogens are methane generating microorganisms who can only survive in anaerobic environments. Because of their microscopic size and inability to survive in air containing oxygen they weren’t identified until the 20th century. Yet suspicions about their existence had been inferred.
In 1776 Alessandro Volta discovered the flammability of marsh gas on Lake Maggiore. Poking the reedy bottom of the marsh with his cane he collected the bubbles in a gas container then set fire to it, producing ‘a beautiful blue flame’. Natural scientists called this ‘swamp air’ ‘carbonated hydrogen’ and in 1865 ‘methan’ was proposed. ‘Methane’ was accepted in 1892.
Pierre Jacques Antoine Béchamp was the first to suspect methane was formed by a microbiological process as the result of a fermentation experiment in 1868. It was not until 1936 that the first methanogen, Methanobacillus omelianskii, was isolated with Delft canal sediment by Horace Albert Barker. This marked ‘the beginning of the modern era for the study of methanogenesis.’
Scientists went on to find out methanogenesis, a form of anaerobic respiration which uses carbon rather than oxygen as an electron acceptor, takes place in three ways: carbon dioxide reduction (hydrogenotrophic methanogenesis), cleavage of acetates (acetoclatic methanogenesis), and the breakdown of methylated compounds (methylotrophic methanogenesis).
II. Ancient Things
In 1997, during an experiment with RNA, Carl Woese discovered that methanogens are phylogenetically different from bacteria and eukaryota (this branch includes fungi, plants, and animals) establishing a third domain on the phylogenetic tree.
This new group of microorganisms was named archaea, ‘ancient things’. Because their ‘methanogenic metabolism is ideally suited to the kind of atmosphere thought to have existed on the primitive earth: one that was rich in carbon dioxide and included some hydrogen but virtually no oxygen’, Woese asserted they could be the earliest living beings on our planet.
According to James F. Fasting their generation of methane, a greenhouse gas, from carbon dioxide and hydrogen, kept the young earth warm between 3.5 and 2.5 billion years ago when the sun burnt only 80 per cent as brightly as today. They played a significant role in the chain of events that led to the development of other life forms.
Methanogens were driven underground by the great oxygenation event 2.3 billion years ago – a time that corresponds with the first Global Ice Age. The world-changing effects of methanogenesis were felt again 252 million years ago when a bacteria transferred two genes to methanosarcina. This allowed them to feed on carbon on the sea floor, releasing immense amounts of methane into the atmosphere, raising the temperatures and acidifying oceans, leading to the Permian-Triassic Extinction Event, which killed 96% of species on the earth.
III. A Dangerous Game
The greenhouse gases responsible for global warming in our current era are carbon dioxide (82%), methane (10%), nitrous oxide (5%), and fluorinated gases (3%). Although methane only accounts for 10% ‘it is 25 times more powerful than carbon dioxide in global warming potential’.
74% of methane emissions in our atmosphere are produced by methanogens. The main sources are wetlands (22%), coal and oil mining and natural gas (19%), enteric fermentation (16%), rice cultivation (12%), biomass burning (8%), landfills (6%), and sewage treatment (6%). Our ability to understand and work with methanogens will play a crucial role in our future. A great deal of research has been carried out into the pros and cons of methanogenesis.
A study by Susannah G. Tringe et al. focuses on ‘a pilot-scale restored wetland in the Sacramento-San Joaquin Delta of California.’ Tringe notes that wetlands are effective carbon sinks, but methane production can outweigh the benefits in terms of emissions of greenhouse gases. By mapping the relationships between microbial communities and gas measurements her group aims to ‘reduce methane flux to the atmosphere and enhance belowground carbon storage.’
Several studies have been carried out on methanogenesis in coal mines. It has been discovered that the majority of emissions from mines are biogenic as opposed to thermogenic and take place by acetoclastic methanogensis from hard coal and mine timber. Ways of using the methane for energy are being explored. Methanogenesis also occurs in shale and experiments in biostimulation to improve productivity in combination with fracking are in progress.
Studies on landfills, a new source of organic (and inorganic) matter for these ingenuous microorganisms, show that methanogenesis, which follows hydrolysis, acidification, and acetogenesis, is an essential process in the breakdown of ‘municipal solid waste’. In landfills, as well as in wetlands, coal, and shale, acetoclastic methanogens work with acetate-producing bacteria in a syntrophic relationship. This also occurs in the breakdown of sewage. Again, ways of using the methane for energy and thus reducing emissions are being explored.
A common theme that cropped up in all these studies is that the complex interrelationships between methanogens and other bacteria and the role of methanogenesis in the global cycles are not fully understood. Nothing is said about the intelligence and agency of these secretive near-invisible beings who have played a key role in the shaping of our climate for billions of years.
Science, measuring, quantifying, postulating, manipulating, rarely listens to or respects its subjects. The Permian-Triassic extinction, which took place as the consequence of a small genetic change, highlights the potential dangers of attempting to manipulate these complex microorganisms. Without understanding, without relationship, we are playing a dangerous game.
IV. Listening to the Deep
For me as an awenydd working with Brythonic cosmology, methanogens, chthonic beings who inhabit the deepest of places and feed on organic matter composed of dead organisms, seem associated with Annwn, ‘the Deep’, the Otherworld, where the dead and dead worlds reside. Death-eaters par excellence, their activities release the gaseous spirits of the dead into the air.
These processes are essential on both physical and spiritual levels and are part of the earth’s innate balance. When this is disturbed, as now, by mankind’s raiding of Annwn for fossil fuels and release of its spirits, extinction events swiftly follow to correct the disequilibrium.
This knowledge from the depths of time is embodied in Brythonic mythology wherein Gwyn ap Nudd is said to contain the spirits of Annwn in order to prevent their destruction of the world.
Whereas we once mined with due reverence for the rules of the gods of the deep (Nodens/Nudd,‘Lord of the Mines’ was venerated at an iron ore mine at Lydney), who keep its spirits in check, their forgetting has led to all-out ravaging with disastrous consequences.
Over two thousands miners in Lancashire alone have lost their lives, many as a result of explosions caused by methane, which is also a threat at landfill sites. Flammable methane haunts the taps of people whose water has been contaminated by fracking. Global warming, caused by greenhouse gases, is claiming the lives of at least ten thousand species a year.
As the death toll rises I believe it is no coincidence that methanogens have begun to reveal themselves to us (as opposed to us thinking we are so clever finding them); coccoid, baccilic, in enigmatic strings and webs, under the UV illumination of fluorescence microscopes. These 3.5 billion year old microorganisms who dwell deep in our guts are clearly communicating.
Will we learn their language? Will we listen? If we do will they lead us to redemption or destruction?
Gwyn ap Nudd,
you who have travelled time
to know the secrets of archaea:
their containment and release,
you who exist in the no-time
of Annwn between life and death
please teach us to listen
with reverence again
before you and your spirits
decide our end.
Carl Woese, ‘Archaebacteria: The Third Domain of Life Missed by Biologists for Decades’, Scientific American, (2012, originally published 1981)
Colin Schultz, ‘How a Single Act of Evolution Nearly Wiped Out All Life on Earth’, Smithsonian
Daniela Buckroithner, ‘Microbiology of Landfill Sites’, University of Natural Resources and Life Sciences, Masters Thesis, (2015)
Fabrizio Colozimio et al.,‘Biogenic methane in shale gas and coal bed methane: A review of current knowledge and gaps’, International Journal of Coal Geology, Vol. 165, (2016)
James F. Kasting, ‘When Methane Made Climate,’ Scientific American, (2015)
Ralph S. Wolfe, ‘A Historical Overview of Methanogenesis’, Methanogenesis: Physiology, Biochemistry & Genetics, (Chapman and Hall, 1993)
Sabrina Beckman et al, ‘Acetogens and Acetoclastic Methanosarcinales Govern Methane Formation in Abandoned Coal Mines’, Applied and Environmental Biology, (2011)
Shaomei He et al., ‘Patterns in Wetland Microbial Community Composition and Functional Gene Repertoire Associated with Methane Emissions’, American Society for Microbiology, (2015)