

Electric life forms that live on energy - jonbaer
http://www.newscientist.com/article/dn25894-meet-the-electric-life-forms-that-live-on-pure-energy.html

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gus_massa
> _As you may recall from high school biology, almost every living organism
> consumes sugar to survive. When it gets right down to it, everything you eat
> is ultimately converted or digested into single molecules of glucose._

This is an oversimplification. Some bacteria have very weird metabolism. (Or,
from the other point of view, some bacteria think that we have a very weird
metabolism :) ). They oxidize and reduce different kind of compounds to obtain
energy. More info:
[http://en.wikipedia.org/wiki/Microbial_metabolism](http://en.wikipedia.org/wiki/Microbial_metabolism)

The [extremetech] article has very few details and I think that it's
misleading. I can't find the original research article.

There are some interesting details in the video. (Is this a video of this
experiment?) Apparently these bacteria use O2 (oxigen) and H2S (hydrogen
sulfide). The metabolism is probably like:
[http://en.wikipedia.org/wiki/Microbial_metabolism#Sulfur_oxi...](http://en.wikipedia.org/wiki/Microbial_metabolism#Sulfur_oxidation)

~~~
vedtopkar
Definitely.

It should also be noted that any organism that uses oxidative phosphorylation
for metabolism (humans included) technically use "pure energy in the form of
electron flow" by having carrier molecules like NADH and FADH2 release
electrons into the mitochondrial membrane. The electrons then flow through a
few proteins, which use the electrons' energy to create a proton gradient in
the mitochondrion, which is then used to create ATP (the "currency" of
chemical energy in many cells).

~~~
pdabbadabba
I agree that the tone is a bit sensationalist. It is New Scientist, after all.
But note that the article itself makes your point:

> That should not come as a complete surprise, says Kenneth Nealson at the
> University of Southern California, Los Angeles. We know that life, when you
> boil it right down, is a flow of electrons: "You eat sugars that have excess
> electrons, and you breathe in oxygen that willingly takes them." Our cells
> break down the sugars, and the electrons flow through them in a complex set
> of chemical reactions until they are passed on to electron-hungry oxygen.

> In the process, cells make ATP, a molecule that acts as an energy storage
> unit for almost all living things. Moving electrons around is a key part of
> making ATP. "Life's very clever," says Nealson. "It figures out how to suck
> electrons out of everything we eat and keep them under control." In most
> living things, the body packages the electrons up into molecules that can
> safely carry them through the cells until they are dumped on to oxygen.

> "That's the way we make all our energy and it's the same for every organism
> on this planet," says Nealson. "Electrons must flow in order for energy to
> be gained. This is why when someone suffocates another person they are dead
> within minutes. You have stopped the supply of oxygen, so the electrons can
> no longer flow."

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tehwalrus
it's an interesting article, and I'd love to understand some of the science
behind it. However, this article didn't tell me much of it.

> _" This is why when someone suffocates another person they are dead within
> minutes. You have stopped the supply of oxygen, so the electrons can no
> longer flow." \- Kenneth Nealson at the University of Southern California_

Chemical oxidation is _not_ , by any sensible analogy, current flow. It is the
exchange of electrons, sure, but the tiny amount of charge flowing anywhere,
and the huge masking that occurs in aqueous systems, would reliably prevent
any normal consequences of current flow (like a B field) from occurring.

Even what happens in neurons isn't really current flow in any real sense, it
is the sympathetic diffusion of ions _sideways_ (in and out of the cell all
the way along its length, if the medic who explained this to me was talking
any sense) which results in charge at one end of the cell "talking to" charge
at the other. Obviously if it were actual "flow", i.e. diffusion, of ions your
reaction times would be a _lot_ slower.

~~~
ajuc
> Obviously if it were actual "flow", i.e. diffusion, of ions your reaction
> times would be a lot slower.

The current in cables work similar way - each electron moves forawrd and back
by small distance, never moving far away from the place it started in.

But the information about movement (the elecrtomagnetic field) spreads from
one electron to another with the speed of light, so the electrons at the end
of cable move as soon as the information gets to them from the begining of the
cable.

That's why when you press light switch the light starts almost immediately,
despite electrons in cables only moving by millimeters per hour.

~~~
tehwalrus
I had forgotten about the analogy with electron speed in wires - thank you! I
remember my music teacher giving me a very funny look when I pointed it out,
and then claiming that electrons must move through wires at the speed of
light...when of course it is the electric field "wavefront" that does so.

------
ejstronge
Did anyone catch what these bacteria use as a source of carbon? Do they reduce
CO2 with electrons directly? I imagine that would be an amazing feat.

~~~
dnautics
shewys are typically in fairly carbon-rich environments, so the answer is
"probably a lot of things", from acetate to glucose, to more complex stuff
like waste nucleotides.

AFAICT, shewys don't typically have CO2 fixation capability. It certainly
would be possible to engineer the pathway in and I think people are trying.

Note that assembling most simple carbon compounds, e.g. acetate, glycerol,
etc. into higher order carbon compounds is not energy-positive (except for
some sugars and fats with the concommitant release of CO2).

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anigbrowl
That's just mindboggling. Perhaps before too long we'll grow computers rather
than manufacturing them. The implications are staggering.

I'm surprised not to have heard more about this before now, but a search for
'shewanella geobacter' yields a rich trove of primary sources.

~~~
zwegner
> Perhaps before too long we'll grow computers rather than manufacturing them.

Check this out:
[https://www.youtube.com/watch?v=WhGG__boRxU](https://www.youtube.com/watch?v=WhGG__boRxU)

Perhaps my favorite TED talk, it was quite mind-blowing to me.

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p1mrx
This seems like something that could one day pose a big problem for
civilization. We have all these electrical outlets just sitting around,
waiting for someone to request huge amounts of energy on demand. If a lifeform
ever evolves to use these effectively, they could spread like wildfire.

~~~
Retric
There tiny. If you actually look at an electrical outlet they have a fairly
large gap to prevent shorting out and potentialy starting a fire.

PS: Science fiction seems to love the trope where tiny change destroys
civilization but life needs far more than just an energy source.

~~~
p1mrx
Plant leaves are also quite large. If we could hypothetically leave the earth
unsupervised for millions of years with the electrical outlets still working,
we'd probably return to find lots of macroscopic electric life.

~~~
Retric
Considering the general lack of a near by water source probably not. Now high
tension powerlines could be an option as there out doors and pump out a lot of
energy which can be collected on both the small and large scales.

Don't forget it's been a billion years and plant's still don't use green
light. For plankton it was reasonable as green does not penetrate as far but
on land it's a huge waste.

~~~
Houshalter
Interesting point, but certainly there must be a reason why they can't use
green light other than just "evolution is slow".

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michaelfeathers
On how they are harvested (my favorite line from the article):

"Basically, the idea is to take sediment, stick electrodes inside and then ask
'OK, who likes this?'

~~~
dnautics
I used to work in the lab adjacent to ken nealson... Another lab in the
department was using this principle for waste water treatment. Stick
electrodes in the water, draw current off of an enforced potential, and see
what survives under this selective pressure. Turns out its a stable population
that is fairly resistant to biotic and abiotic inputs... Just let the biology
figure it out. The output water is really clean, too.

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namuol
Neat. Reminds me of Slime Mold.

[https://www.youtube.com/watch?v=czk4xgdhdY4](https://www.youtube.com/watch?v=czk4xgdhdY4)

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nnq
> A slightly higher voltage offers an excess of electrons; a slightly lower
> voltage means the electrode will readily accept electrons from anything
> willing to pass them off.

...is it just my before-coffee hangovered mind, or _they got this completely
backwards?!_ ...would be really sad since NS is one of the few layman friendly
decent-quality source of science news :(

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tomrod
Two thoughts:

1\. Harvesting bioelectic generation ability would be neat

2\. Possible vector for metabolic disorders?

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iwwr
Alright, but what kind of life form would create the circuits and the voltage
sources to sustain an electric/electronic life-form ecosystem? The equivalent
of plants, algae or cyanobacteria.

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typon
This headline makes zero sense. Doesn't everything live on energy?

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hyp0
Maybe this is the kind of space-life metabolism we should be looking for?

Cue: Larry Niven's _Outsiders_ , who live on the difference in electric
potential between light and shadown.

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Lambdanaut
Anyone have any theories on how this could have evolved? I have to wonder what
sorts of minuscule electric currents they're feasting on down their
underground.

~~~
dnautics
There's electrochemical gradients just about anywhere... If you have for
example stratified rock, there's energy in the differing potentials between
the layers.

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KamiCrit
Reminds me of the Space Odyssey series:
[http://www.aleph.se/Trans/Cultural/Art/2001.html](http://www.aleph.se/Trans/Cultural/Art/2001.html)

"In these, they roamed among the stars. They no longer built spaceships, they
were spaceships.

But the age of Machine-entities swiftly passed. In their ceaseless
experimenting, they had learned to store knowledge in the structure of space
itself, and to preserve their thoughts for eternity in frozen lattices of
light. They could become creatures of radiation, free at last from the tyranny
of matter.

Into pure energy, therefore, they presently tranformed themselves; and on a
thousand worlds, the empty shells they had discarded twitched for a while in a
mindless dance of death, then crumbled into rust.

Now they were lords of the galaxy, and beyond the reach of time. They could
rove at will among the stars, and sink like a subtle mist through the very
interstices of space. But despite their godlike powers, they had not wholly
forgotten their origin, in the warm slime of a vanished sea."

~~~
Terr_
Reminds me of the progression in Asimov's "The Last Question".

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ghkbrew
I'd like to point out that every green plant you see outside your window is
getting its energy from _pure_ _electro-magnetic_ _radiation_! Which I
honestly think is a cooler accomplishment. And I would argue that light is
just as pure a form of energy as an electric gradient if not more so.

Yes, the fact that a there are bacteria out there doing this is really cool.
However, the ridiculous hype science and tech reporter feel the need to put in
their articles is just annoying.

~~~
byerley
To me, this seems interesting because of its potential impact on us rather
than an impressive feat of evolution.

We'll call this science fiction, but - imagine doing your wiring on the fly
with self-organizing bacteria, or having to worry about bacteria evolved to
leach off your circuit board.

Since we think of metal and electricity as very lifeless, the author is right
to point out that this seems alien, even if it's an obvious and less-evolved
form of life.

~~~
ivanca
What if this "less-evolved" system is actually a step forward in our evolution
as species? Because we use a lot of electricity for the machines required to
create, maintain (and promote) our food, what if we could just skip that and
directly plug the energy into ourselves?

~~~
logicchains
It can be measured; here's a page listing the energy efficiency of various
foods:
[http://www.theoildrum.com/node/6252](http://www.theoildrum.com/node/6252). It
appears it would depend on what we were giving up; if we replace meat with
direct energy, we could save around 95%, for instance, but if we replaced
grain with electricity we'd save much less, as grain is already fairly
efficient.

~~~
Retric
That link ignores sunlight.

Average Corn yield is ~160 bushels per acer. 60lb per bushel. An acre is 4,046
square meters. A square meter gets 1kw in full sunlight. Call it 8 hours a day
of sunlight. Corn takes 63 to 92 days so you can get 2 yeilds per year in some
area. Call it 72 for sweet temptation. 72 * 8 * 4,048 / 160 / 60 = ~242 kwh
worth of sunlight per pound of corn.

Note: Solar cells are ~22% efficient but they also work all year.

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andrewflnr
While this is quite fascinating, I resent the repeated statement that
electricity is the purest form of energy. It just seems that way because it's
convenient for a technological civilization like ours to sling around. IMO the
purest form of energy is kinetic.

~~~
gilgoomesh
Of course, there's no such thing as "pure energy" because everything is
energy.

It is far better to think about the _simplest_ forms of energy. And the
simplest would be the different force carrying particles:

[http://en.wikipedia.org/wiki/Force_carrier](http://en.wikipedia.org/wiki/Force_carrier)

These particles mediate the fundamental particle interactions and therefore
are the simplest forms of energy possible.

As for whether kinetic energy is the simplest... it's really more of a
multiplier on top of existing force carriers rather than an energy on its own.
For example: higher energy photons have higher momentum but it's the photon
that's the carrier, it just exists at different levels.

~~~
cLeEOGPw
I think "pure" just means that there are raw electrons in contrast to complex
molecules with a charge.

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dang
Url changed from [http://www.extremetech.com/extreme/186537-biologists-
discove...](http://www.extremetech.com/extreme/186537-biologists-discover-
electric-bacteria-that-eat-pure-electrons-rather-than-sugar-redefining-the-
tenacity-of-life), which points to this.

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31reasons
"This is why when someone suffocates another person they are dead within
minutes. You have stopped the supply of oxygen, so the electrons can no longer
flow"

Oh i see, that is what happens. That makes sense now. Didn't know New
Scientist has CSI edition too.

~~~
imjustsaying
I also had to do a double take when reading this part. A rather interesting
Freudian slip that grammar implied.

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kv85s
[https://www.youtube.com/watch?feature=player_detailpage&v=ij...](https://www.youtube.com/watch?feature=player_detailpage&v=ijAYN9zVnwg#t=31)

I can't be the only one who thought of this when reading the article's title
:)

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devgutt
the force...Jedi is coming

