Evolution: new type of Archaea found: (Evolution)

by David Turell , Friday, May 07, 2021, 20:27 (1084 days ago) @ David Turell

They have a differing metabolism:

https://www.sciencenews.org/article/climate-microbes-recycle-carbon-methane-archaea-mic...

"Now, De Anda and her colleagues have identified an entirely new phylum — a large branch of related organisms on the tree of life — of archaea. The first evidence of these new organisms were within sediments from seven hot springs in China as well as from the deep-sea hydrothermal vents in the Guaymas Basin in the Gulf of California. Within these sediments, the team found bits of DNA that it meticulously assembled into the genetic blueprints, or genomes, of 15 different archaea.

"The researchers then compared the genetic information of the genomes with that of thousands of previously identified genomes of microbes described in publicly available databases. But “these sequences were completely different from anything that we know,” De Anda says.

***

"Brockarchaeota, it turns out, actually live all over the world — but until now, they were overlooked, undescribed and unnamed. Once De Anda and her team had pieced together the new genomes and then hunted for them in public databases, they discovered that bits of these previously unknown organisms had been found in hot springs, geothermal and hydrothermal vent sediments from South Africa to Indonesia to Rwanda.

***

"...the team expected that — like other archaea previously found in such environments — these archaea would be methane producers. They do munch on the same materials that methane-producing archaea do: one-carbon compounds like methanol or methylsulfide. “But we couldn’t identify the genes that produce methane,” De Anda says. “They are not present in Brockarchaeota.”

"That means that these archaea must have a previously undescribed metabolism, through which they can recycle carbon — for example in sediments on the seafloor — without producing methane. And, given how widespread they are, De Anda says, these organisms could be playing a previously hidden but significant role in Earth’s carbon cycle."

Comment: Only known since 1970, it is not surprising new ones are turning up.