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Bacteria Propel Themselves with Slime Jets 50

Posted by Hemos
from the ka-WHOOSH dept.
galactic_grub writes "Scientists have discovered that some bacteria propel themselves along using tiny jets of slime. According to this story on NewScientistTech, the researchers previously thought the slime was a lubricant. They believe the same technique could be used to move nano-devices around."
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Bacteria Propel Themselves with Slime Jets

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  • Eating nanobots? (Score:4, Interesting)

    by fbjon (692006) on Monday April 03, 2006 @09:21AM (#15049772) Homepage Journal
    Is it just me or are there no comments in this story?

    In any case, how would the nanobots produce the propellant fluid, they'd have to be able to consume something? Perhaps they're counting taking in and storing some available fluid while passing through, like in the human blood stream, or somesuch.

    • Re:Eating nanobots? (Score:4, Interesting)

      by Forbman (794277) on Monday April 03, 2006 @12:51PM (#15051861)
      Well, most animal slime is a mix of sugars and water. The sugars hold a large amount of water, relatively speaking, so if it's the same with bacteria, then the bacteria does not have to expel much of the sugar mix, so the metabolic demands are gonna be relatively small.
      • Beautiful. Now, how would nanobots produce the slime? Where do they get the sugar? The water? How do they assemble the stuff? Maybe a biologic component to them? Seems like a lot of machinery to me, no matter what. If we have nanomotors, I think nanopropellers would produce motive force for any machine large enough to take advantage of liquid jet propellant.
        • by Anonymous Coward on Monday April 03, 2006 @01:22PM (#15052121)
          You're assuming propellers work the same at nano scale. They don't.

          Remember, this is a realm of counter-intuitive phenomena that you can't just "gut feel" your way around.

          Odds are good that if bacteria do it, then it's an extraordinarily efficient way to do things, and we should seriously consider it. Remember that
          a) they evolve much faster than we do
          b) are much older (predating eukaryotes by 2 billion years or so)
          c) they live at the micro/nano scale boundary.

          Call me when you've got that kind of experience under your belt ;)
    • In any case, how would the nanobots produce the propellant fluid, they'd have to be able to consume something? Perhaps they're counting taking in and storing some available fluid while passing through, like in the human blood stream, or somesuch.

      Once they reduce everything to grey goo [wikipedia.org], they'll have plenty of fuel for their slime jets.

      Err, tha'td be goo jets, I guess.

      --
      This sig intentionally left blank

  • by American AC in Paris (230456) * on Monday April 03, 2006 @11:43AM (#15051194) Homepage
    Apparently, scientific progress goes "Ew."
  • Nanobots (Score:4, Funny)

    by Eightyford (893696) on Monday April 03, 2006 @11:45AM (#15051210) Homepage
    They believe the same technique could be used to move nano-devices around."

    Would that really be the most efficient way of moving a nano-device? I doubt it. I think we'll see little sperm bots first.
    • Re:Nanobots (Score:4, Funny)

      by linzeal (197905) on Monday April 03, 2006 @11:48AM (#15051240) Homepage Journal
      I want women to have little anti-sperm nano robot defenses so I can get like mecha-suit sperm bots that tries to invade her womb like little futuristic crusaders to implant my seed. Also they could walk around and under people's doors to impregnante women while they sleep. This is what scientific progress means to me.
    • by misleb (129952)
      Shhhhh! We're already being replaced by mechanical penises. The last thing we need are mechanical sperm to completely remove us from the equation!

      -matthew
  • by jcr (53032) <jcr AT mac DOT com> on Monday April 03, 2006 @11:50AM (#15051262) Journal
    Gee, I thought it was just politicians...

    -jcr
  • Nick (Score:4, Funny)

    by deanj (519759) on Monday April 03, 2006 @11:58AM (#15051351)
    I think the implication of this are obvious. Let me be the first to say:

    I, for one, welcome our Nickelodeon overlords.
    • I, for one, welcome our Nickelodeon overlords.

      I wonder what they meant by that?

      I don't know (*gasp* flesh eating bacteria attack!!!!)

  • by Glog (303500) on Monday April 03, 2006 @12:11PM (#15051469)
    "Self-propelled through slimy jets" is also part of the job credentials of any current and/or future RIAA president. And yes, many many bacteria have suffered and died in order to perfect this method of propulsion.
  • by maubp (303462) on Monday April 03, 2006 @01:13PM (#15052057)
    "Scientists have discovered that some bacteria propel themselves along using tiny jets of slime".

    No - that has been known for a long time. This research mearly elucidates the mechanism. Which is nice. But, in addition to the slime nozzles at the back end, .

    Did you know that at the front end Myxo bacteria have "grappling hooks" which that can extend and then retract? Search for pilus retraction...

    Or that they are pack hunters? Or that they will commits suicide to save their buddies [newscientist.com]?

    Myxobacteria - they're great!
    • From TFA:
      "Myxobacteria are micrometre-scale filament-shaped organisms that glide along surfaces, leaving a trail of slime in their wake. Biologists were convinced the bugs produced the slime as lubricant, but couldn't explain how they generated the force to move."

      That second phrase, "couldn't explain how they generated the force to move" seems to contradict your statement that scientists already knew how they moved.
    • by Dachannien (617929) on Monday April 03, 2006 @03:26PM (#15053027)
      Or that they will commit suicide to save their buddies?

      The amoeba Dictyostelium discoideum will also sacrifice itself to help propagate the species when food supplies are dwindling. Rather than just die and release protective substances, however, the individual cells actually form a multicellular slug capable of locomotion. Once the slug has migrated, it sends up a stalk with a spore-laden "fruiting body". The cells in the stalk die, while the spores are able to travel through the air to an environment where food is hopefully more plentiful.

      Of course, being an amoeba, Dicty can locomote without the need for slime jets.
      • Yeah - Myxo and Dicty both have lots of cool tricks.

        The Myxo and Dicty spore formation process (with most cells dying and releasing their nutrients for the good of the minority which form spores) is very similar.

        As a family the myxo bacteria have a whole range of lovely fruiting bodies.

        Did you know they where first mis-classified as fungi when they were spotted down a microscope?
    • Does it mean I'm a nerd if I'm sitting in a college computer lab reading slashdot and wondering if the person next to me would be offended if I started Wiki'ing for Myoxobacteria so that I can read about all the neat stuff they do?
  • In Soviet Russia, bacteria slimes you!

    Actually, in Soviet Russia, I think the bacteria probably killed a lot of people. They don't have the best medical facilities over there.

    I feel so dirty.
  • That's what I've been calling Southwest Airlines. Greyhound busses of the sky baby!

    Amazing that bacteria can book a reservation on SouthWest with such tiny appendages.

    And how do you distribute frequent flier miles through a colony of millions?
  • Doesnt that sound a bit too much?

    The slime is probably composed almost entirely of proteins, carbohydrates and water, and it is probably about the same that covers many bacteria. (No idea about this specific one though, but since it has developed a propulsion system based on it, I would guess it is) And the slime ususally works as a glue, so it can stick to surfaces - Which also means it holds it back. So for this propulsion system to work, it needs to deliver quite a 'splat' so to say..

    But hey, just gue
  • by san (6716) <[ ] ['' in gap]> on Monday April 03, 2006 @04:39PM (#15053592)

    This may seem a very inefficient way to move about, but things work very differently on the lengthscale of bacteria.

    For example, most moving bacteria use propellor-like objects (flagellae [wikipedia.org]) to propel themselves, but the way they work is very different from propellors.

    Propellors use Bernouilli's principle [wikipedia.org] to create a pressure difference between the front and the rear of the propellor, thereby 'sucking' themselves forward.

    Bacteria, because they're so small, live in a surrounding where water has an effective viscosity higher than molasses on our lengthscale (it has to do with a dimensionless number for friction in hydrodynamics called the Reynold's number [wikipedia.org], that scales with inverse length).

    Bacteria have to push themselves forward in something that really doesn't want to move and creates a lot of friction; all kinds of movements that we would think of intuitively possible are impossible under these circumstances. For example, some hydrodynamics people talk about the 'scallop theorem', which states that at these conditions it's impossible something to move forward like a scallop: rapidly closing its shell and opening it again.

    Most flagellae are either spiral structures or stiff rods that get swayed back and forth; none use Bernoulli's effect, but tend to make use of the high viscosity by pushing against the fluid.

    These bacteria make a starch gel to propel themselves: the sugar concentration doesn't need to be very high to get a decent gel, and the speeds they obtain sound incredible (usually we're talking 10 microns per minute, not per second).

    • Propellors use Bernouilli's [sic] principle to create a pressure difference between the front and the rear of the propellor, thereby 'sucking' themselves forward.

      Baloney. This is not true of airplane wings, and it is not true of propellers. If you believe it, then ask yourself how airplanes fly inverted, toy planes with flat wings fly, toy helicopters with flat propeller blades rise, and fans with flat blades blow air.
      • I've just looked it up (here [wikipedia.org]) and you're mostly right. The main lift comes from the pressure obtained by deflecting the airflow; something that stops working as viscosity increases.

        In practice, an airfoil does make of Bernoulli's effect to help deflect air downwards, thus increasing the lift (I'd guess that that's the reason why airplane wings 'bulge' upwards).

  • Anyone else picturing PacMan?

A mathematician is a device for turning coffee into theorems. -- P. Erdos

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