• This forum is specifically for the discussion of factual science and technology. When the topic moves to speculation, then it needs to also move to the parent forum, Science Fiction and Fantasy (SF/F).

    If the topic of a discussion becomes political, even remotely so, then it immediately does no longer belong here. Failure to comply with these simple and reasonable guidelines will result in one of the following.
    1. the thread will be moved to the appropriate forum
    2. the thread will be closed to further posts.
    3. the thread will remain, but the posts that deviate from the topic will be relocated or deleted.
    Thank you for understanding.​

Biology: Microbes in sub-sea-floor sediments live on astonishingly little energy

Introversion

Pie aren't squared, pie are round!
Kind Benefactor
Super Member
Registered
Joined
Apr 17, 2013
Messages
10,642
Reaction score
14,865
Location
Massachusetts
(An earlier post was made here about these microbes, but that one was talking to the possible age of these organisms, where this article talks in a bit more detail about the extreme low-energy lifestyle they live. Amazing stuff.)

https://www.quantamagazine.org/zombie-microbes-redefine-lifes-energy-limits-20200812/

Quanta Magazine said:
...

They found that the cells buried in ocean sediments operate at incredibly low power levels. In total, microbes in those sediments, which in some places might extend kilometers below the seafloor, collectively use a mere tenth of a percent of the power consumed in the upper 200 meters of the ocean. Each cell, on average, survives its sediment burial at a power level significantly lower than that of “some of the most energy-starved things in the world,” as Lloyd puts it — and orders of magnitude lower than that of any organism ever measured in lab settings.

The calculations were in line with earlier theoretical work by members of the team who in 2015 tried to estimate the lowest amount of power needed for life, based on the premise that even deeply dormant cells must repair random damage to their essential molecules to survive. They found that for individual cells, this power minimum hovers around a zeptowatt, or 10−21 watts. That is roughly the power required to lift one-thousandth of a grain of salt one nanometer once a day. (For reference, a human body uses on average about 100 watts, the power of a reading light.) The new model suggests that cells living in sub-seafloor sediments are drawing only slightly more power than that.

Although these kinds of measurements have previously been made for individual sub-seafloor sites, they have tended to exist somewhat in isolation. “We’ve done a ton of poking individual holes here and there,” Lloyd said, “but this paper actually puts that together and puts it into a global perspective.”

A Biosphere of Stasis

The implication of the study’s estimates is that this underground biome has almost no cell division: Some individual cells down there might be 100 million years old. It also means that in all that time, those cells might not have evolved or changed much at all. It’s a biosphere characterized by stasis. “Really, most of the cells are barely hanging on,” Amend said. “Our concept of how cells evolve goes out the window for this incredibly large biosphere.”

...
 
Last edited: