Monday, March 17, 2008

Speedy ocean bacteria dart after food

Who knew ocean bacteria are faster than a cheetah? And even more amazing, who knew that this darting behavior is globally important, possibly impacting climate change? How fast are they exactly? See geeky numbers below.

What are ocean bacteria chasing, that they have to be speed demons? Micro patches of food that don't last very long, like the yummy goop that leaks out of popped algae or the food trail left behind by a sinking particle.

Scientists set up artificial food patches and filmed through a microscope to observe the streaking bacteria. Roman Stocker, one author of the paper, says "If you are a bacterium, the ocean looks like a desert to you, where food mostly comes in small patches that are rare and ephemeral. When you encounter one, you want to use it rapidly."

OK, so how fast are they really? The single rotating flagellum of P. haloplanktis propels it forward at the amazing speed of 500 body lengths per second, way faster than a cheetah's mere 30 body lengths per second. That's relatively blazing fast for the ocean bacteria. Of course, with a body length of 2 microns (0.000002 meters), this relative speed has the microscopic bacteria swimming at the amazing pace of about 10 feet per hour. Wow. That's just a bit faster than a slug, but slower than a snail.

And what's the climate change link? Scientists believe that the actions of bacteria may determine whether oceans produce or consume CO2 in the future. We gotta know.

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