Breathing Metal

Those of you familiar with Blindsight‘s Scramblers may remember this quirk about their physiology: they didn’t keep all their metabolism on the inside.

“I don’t think Rorschach’s magnetic fields are counterintrusion mechanisms at all. I think they’re part of the life-support system. I think they mediate and regulate a good chunk of scrambler metabolism… If I’m right, I’m not even dealing with complete organisms here.”

I kept it all fuzzy and hand-wavey — microscopic shards of magnetite in scrambler cells, dancing to the precise twitch of Rorschach’s filigreed magnetic fields — because I didn’t in truth have any idea how an inside/outside metabolism would really work. I thought it was a really cool idea, though.

Count on Nature to think of it a few billion years before I did. Are you ready for metal-breathing microbes?


Not scramblers, exactly. But definitely nonsentient. Photo credit Pacific Northwest National Laboratory.

I wasn’t, not until last Thursday. That’s when I received an e-mail from one Jake Cohen, a dude who gets more out of my writing than some might consider normal. It happens, occasionally: someone drops a line mentioning that Blindsight inspired her degree in cognitive linguistics, or that an idea gleaned from Starfish allowed him to commit the perfect murder, or that Maelstrom‘s take on digital wildlife informed some project over at Lawrence Livermore that no one’s allowed to talk about1. Jake, a microbiologist by trade, admitted to being especially fond of my rifters books. He pointed me to the Harvard lab where he’s about to start a PhD on hydrothermal vent ecology, and I dutifully clicked the link to check it out.

Which is where I encountered the photo caption “Extracellular electron transfer experiments at 1 kilometer below sea level in the Monterey Canyon”, slipping past almost too quickly to notice on Prof. Girguis’s splash page.

Extracellular electron transfer? Does that mean what I think it does?

I wrote Jake back, and yes: yes it does.  But don’t take my word for it, or even his: say hello to Shewanella oneidensis  — a bacterium that, while facultatively aerobic, can get by in anoxic environments by breathing metals2. Here’s the money shot:

“…can also thrive without the gas if it must, thanks to energy-generating chemical reactions that transfer electrons from inside its cells to outside minerals that contain metals such as iron.”

—or, to quote my newfound go-to guy at Harvard, “[it] works mostly like a regular electron transport chain, except instead of the terminal electron acceptor being inside the cell, those bacteria use a carrier molecule to pick up those electrons and shuttle them outside of the cell to an acceptor they’re growing on.” Apparently this also raises certain commercial possibilities in the biobattery department.

Inside/outside metabolism. Holy shit.

I wish I’d known about this while I was writing Blindsight. You can be damn sure it’s going to make a walk-on in Echopraxia, though.


1 I exploit these folks mercilessly, trading on their goodwill by hitting them up for expertise the next time I want to write about something without having to get a goddamn degree in it first.

2The Science article contains an alleged link to the original PNAS online paper, but it’s broken, and PNAS’s own early-edition abstracts for the 25th don’t seem to list it. Don’t know what’s up with that.

This entry was posted on Wednesday, March 27th, 2013 at 7:05 am and is filed under biochem, biology, blindsight, deep sea, Dumbspeech, marine. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.

17 Responses to “Breathing Metal”

  1. Daniel

    I’d be interested to see which materials it can shunt electrons to.

  2. Steve Halter

    Well, that’s all kinds of cool.

  3. Charles R

    Or what about Borrelia requiring manganese and not iron? Is this similarly wacky to metal-breathers?

  4. Sheila

    oh, I am going to book mark this next to the magnetic bacteria on the ocean floor.

  5. Joris M

    Nice, I remember reading some years ago about bacteria in the ocean floor that used wire-like electron transport to make use of several resources simultaneously. A search now results in Desulfobulbus, but I believe their discovery is more recent (although earlier reports on yet unidentified might match ).

    And trying to find a reference I stumbled upon Geobacter sulfurreducens, that apparently forms colonies like a conductive wire doing something similar.

    Nature is really cool.

  6. Alyx Dellamonica

    Oh, that is so damned cool!!

  7. Doug M


    At LLNL, we live to serve. Call anytime.

  8. pG

    Dude. You’d better be wrong about the vampires.

  9. Bastien

    Dude. You’d better be wrong about the vampires.

    With his current track record, I wouldn’t get your hopes up. But hey, at least we’ll probably get computer inlays and eye caps pretty soon.

  10. Tom
  11. Seruko

    Bastien: With his current track record, I wouldn’t get your hopes up. But hey, at least we’ll probably get computer inlays and eye caps pretty soon.


    well the whole head’s up display AR things is moving from the fighter pilot cock pit to glasses as of last year, in a year or five it will all be induction brain insertion anyway. Hopefully that means I wont have to poke my eyeballs to get AR anytime soon.
    Any Who.
    Your writing is starting to seem less art imitating life and more Heinlein-ian world as lit. Which is both spooky and silly. Maybe you should start writing Rom-Com’s and Happy ever afters?

  12. Sheila


    disagree with your observation, but wanted to say that I’d like a dystopian comedy of manners.

  13. Seruko



    You disagree with all of my observations or just one of them. There’s some meat there.

  14. Sheila


    I was replying to the humorous recommendation for rom-com’s with happy endings. Dystopian Jane Austin, though? would absolutely love.

    I don’t know how well induction technology would work, so I’m agnostic for that. I agree I would love non invasive heads-up displays.

  15. foreign noise

    In this context, I think you may really enjoy The Extended Organism by J Scott Turner.

  16. Joris M

    @ Tom,

    That seems to be referring to the article I remember, at least it is the correct time period and a Journal I was likely to read. Thanks.

  17. lancel premier flirt

    it simply screams Mug me We’ve more income than I am aware of where to start with…