Natures wonders: symbiosis by bacteria using nitrates (Introduction)

by David Turell , Wednesday, March 03, 2021, 19:14 (1359 days ago) @ David Turell

On onboard bacteria uses nitrate metabolism to supply energy to its host:

https://phys.org/news/2021-03-symbiosis-endosymbiont-derives-energy-respiration.html

"Researchers from Bremen, together with their colleagues from the Max Planck Genome Center in Cologne and the aquatic research institute Eawag from Switzerland, have discovered a unique bacterium that lives inside a unicellular eukaryote and provides it with energy. Unlike mitochondria, this so-called endosymbiont derives energy from the respiration of nitrate, not oxygen. "Such partnership is completely new," says Jana Milucka, the senior author on the Nature. "A symbiosis that is based on respiration and transfer of energy is to this date unprecedented."

"This was also the case with the symbiosis discovered by the Bremen scientists in Lake Zug in Switzerland. "Our finding opens the possibility that simple unicellular eukaryotes, such as protists, can host energy-providing endosymbionts to complement or even replace the functions of their mitochondria," says Jon Graf, first author of the study. "This protist has managed to survive without oxygen by teaming up with an endosymbiont capable of nitrate respiration." The endosymbiont's name, Candidatus Azoamicus ciliaticola, reflects this; a 'nitrogen friend' that dwells within a ciliate.

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"'Our endosymbiont is capable of performing many mitochondrial functions, even though it does not share a common evolutionary origin with mitochondria," says Milucka. "It is tempting to speculate that the symbiont might follow the same path as mitochondria, and eventually become an organelle."

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"This finding provokes many exciting new questions. Are there similar symbioses that have existed much longer and where the endosymbiont has already crossed the boundary to an organelle? If such symbiosis exists for nitrate respiration, does it also exist for other compounds? How did this symbiosis, which has existed since 200 to 300 million years, end up in a post-glacial lake in the Alps that only formed 10,000 years ago? Moreover: "Now that we know what we are looking for, we found the endosymbiont's gene sequences all around the world," says Milucka. In France, as well as in Taiwan, or in East African lakes that in part are much older than Lake Zug. Does the origin of this symbiosis lie in one of them?"

Comment: just another evidence that life has God-given methods to survive and thatt survival does not drive evolution