Articles about Archaea

The structure of the various groups of archaea resulting from this study with eukaryotes as part of this taxonomic domain

An article published in the journal “Nature” reports the results of a genetic study on the archaea Asgard that expands the genetic diversity of this group of microorganisms and concludes that the taxonomic order Hodarchaeales is the one most closely related to eukaryotes, the organisms that make up all forms of multicellular life on Earth. A team of researchers conducted a genetic analysis of Asgard archaea from samples collected at 11 locations around the world in a genomic research using state-of-the-art analysis techniques. The conclusion is that eukaryotes constitute a group within the Asgard archaea, from which they may have directly evolved.

An Asgard archaeon of the proposed species Lokiarchaeum ossiferum

An article published in the journal “Nature” reports a study on archaea that belong to the proposed superphylum called Asgard and in particular on their characteristics that make them a possible evolutionary missing link with eukaryotes. A team of researchers formed by the collaboration of the working groups of Christa Schleper of the Austrian University of Vienna and Martin Pilhofer of ETH Zurich was successful in cultivating a species belonging to this group of microorganisms to study them in the laboratory. This allowed conducting thorough examinations of their cellular structures such as the extensive cytoskeleton.

Some of the microfossils discovered (Image courtesy B. Cavalazzi)

An article published in the journal “Science Advances” reports the discovery of microfossils of the oldest known methanogenic microorganisms, with an estimated age of 3.42 billion years. A team of researchers led by Professor Barbara Cavalazzi of the University of Bologna, Italy, discovered these microfossils in South Africa, in the area known as the Barberton Greenstone Belt. These microorganisms lived in a system of hydrothermal veins and show similarities with today’s archaea. Their study offers insights into early life forms on Earth and the possibilities for life forms to emerge in similar environments elsewhere in the universe.

Ethanoperedens thermophilum in red and its symbiote Desulfofervidus auxilii in green

An article published in the journal “mBio” reports the discovery of an archaeon that feeds on ethane in hydrothermal vents at the bottom of the Guaymas Basin, in the central area of ​​the Gulf of California. A team of researchers led by Gunter Wegener of the Max Planck Institute for Marine Microbiology proposed the name Ethanoperedens thermophilum for this archaeon that lives in symbiosis with a bacterium already known for which Wegener and his collaborators proposed the name Desulfofervidus auxilii. The interest in these microorganisms goes beyond biological curiosity because the metabolic process that degrade ethane is reversible, and this means that other similar archaea could transform carbon dioxide into ethane. This would lead to their use for the production of ethane, the second most common component of natural gas after methane with 15%.

An Asgard archaeon could provide the key to understanding the birth of the eukaryotic cell

An article published in the journal “Nature” reports a study on an archaeon called Candidatus Prometheoarchaeum syntrophicum, part of the proposed phylum Lokiarchaeota. A team of researchers took samples from the bottom of the Pacific Ocean near the Japanese coasts, managing to cultivate these Archaea contained in a special laboratory environment specifically created. Years of studies made it possible to separate various strains and to discover that some have long and branched protrusions, a feature that led the researchers to suggest that in the past a bacterium became entangled in similar protrusions becoming an organelle of what became over time a eukaryotic cell.