Archaea

Some meteorite NWA 1172's dust fragments colonized by Metallosphaera sedula (Image courtesy Tetyana Milojevic)

An article published in the journal “Scientific Reports” describes a study on the ability of a species of archaea called Metallosphaera sedula to grow into typical meteorite materials using the metals they contain as an energy source. A team of researchers led by astrobiologist Tetyana Milojevic of the University of Vienna examined these archaea living and interacting with a real meteorite. The results can provide clues to the origin of life on Earth thanks to the possibility of identifying with greater certainty microfossils containing metals. This also means having better chances of evaluating possible traces of microscopic life found in other places in the solar system.

An abundance of Archaea in sediments beneath the ocean floor

An article published in the journal “Science Advances” reports an abundance of ammonia-oxidizing archaea in microbial communities in sediments beneath the seafloor of the North Atlantic Ocean. A team of researchers led by William Orsi of the Ludwig-Maximilians-Universitaet (LMU) in Munich, Germany, discovered that archaea not only survived for millions of years in sediments that can reach over two kilometers below the ocean floor but adapted to those conditions better than bacteria and could play an important role in the geochemical cycles of carbon and nitrogen in that ecosystem.

A remarkable diversity of microorganisms discovered in one of Yellowstone springs

An article published in the journal “Nature Communications” reports the discovery of a diversity never encountered before in the microorganisms found in one of the hot springs of Yellowstone National Park, in the USA. A team of researchers from Montana State University (MSU) used genomic tools to examine the microbial community in the source called Smoke Jumper 3 (SJ3), discovering both bacteria and Archaea that represent about half of the known branches of these domains of life. It’s an extraordinary discovery because understanding which geological and biological processes can lead to such diversity can provide new information on the reasons why certain life forms can emerge and thrive.

Asgard archaea in the tree of life (Image courtesy Eva Fernandez-Caceres)

An article published in the journal “Nature” describes the discovery of new microorganisms that provide more information on the evolution of eukaryotic organisms, the ones formed by complex cells. The new species discovered are archaea that were called Thor, Odin and Heimdall, simpler organisms that however have some characteristics found only in eukaryotes and together with another archaea family called Loki whose discovery was announced in September 2015, form a group that was called the Asgard archaea.

The tree of life

An article published in the journal “Nature Microbiology” describes a genetic research that offers a broader vision of the tree of life. A team of researchers of the University of California, Berkeley, led by Laura Hug, who now works at the biology faculty of the University of Waterloo, Ontario, Canada, built a new tree of life showing a diversity formed for two thirds by bacteria and archaea.