Breatharian bacteria discovered in Antarctica
The world-first discovery opens new possibilities for ET.
Bacteria in the frozen wastes of Antarctica can survive on air alone.
Rather than relying on sources that power other life on Earth – photosynthesis, sugar, geothermal energy – they split hydrogen for energy and fix carbon from carbon dioxide and carbon monoxide.
The world-first discovery that bacteria are capable of such a feat was reported in Nature by a team of Australian and New Zealand researchers.
The finding “opens up the possibility of atmospheric gases supporting life on other planets”, says team member microbiologist Belinda Ferrari of the University of NSW.
The Antarctic’s interior ‘deserts’ are the most barren on Earth. Zero vegetation, prolonged periods of darkness or searing ultraviolet radiation, and cycles of freezing and thawing that can rot the very stones, make the deserts particularly inclement locations for life.
Scientists have known since 2000, by testing for DNA fragments, that microbial communities somehow survive in the soil. “But how was a mystery,” says Ferrari.
This time round Ferrari and her colleagues used metagenomic techniques to put those DNA fragments together and discover their genetic secrets. They collected DNA from two eastern Antarctic sites: one near Casey Station in Wilkes Land and the other a few hundred kilometres from Davis Station in Princess Elizabeth Land.
The DNA fragments were pieced together like a jigsaw puzzle to reveal the near-complete genomes of 23 individual microbial species, including Acinetobacter as well as two previously unknown bacterial phyla, named WPS2 and AD3.
By peering at the individual genes of these newly identified bacteria, the researchers found two big clues that they had stumbled onto a new form of life chemistry dubbed ‘trace gas carbon fixation’.
One was a gene for an enzyme called high affinity hydrogenase. It is capable of pulling in trace amounts of hydrogen from the atmosphere and splitting the molecule to produce energy.
The other was a set of genes for a weird form of Rubisco – an enzyme complex usually involved in photosynthesis.
But not here: the weird Rubisco used hydrogen power to drive carbon fixation. The carbon was sucked in by enzymes that bind trace amounts of carbon dioxide and carbon monoxide, fixing them into carbon compounds.
Ferrari notes they did not detect any genes for true photosynthesis so trace gas carbon fixation is the main game for this extreme community.
“It looks like a process capable of feeding a whole web of life,” he says.
Bacterial species in Antarctica can split hydrogen for energy. Some belong to the Acinetobacter family shown here.