Why radioactivity-eating bacteria are important

I had heard of them - vaguely - and ignored the subject.  Who cares if there are radiotolerant bacteria that can ingest radioactive waste?  The material would still be radioactive.  It's not like the hydrocarbon-eating organisms that can ingest crude oil and poop out pancakes. 

I was wrong, as I learned in a column at The Last Word on Nothing.

In 2002, researchers there found a mysterious slime on a monitoring probe in one of the site’s high-level waste tanks. That slime turned out to be Kineococcus radiotolerans, a microorganism that laughs at radiation doses a thousand times what would put one of us humans in a box...

Then there was Deinococcus radiodurans, found happily munching on radioactive waste leaking out of the 50-year-old nuclear waste tanks under the Hanford nuclear reservation...

[T]he most important aspect of cleaning up radioactive material is keeping it from ending up in the water. That’s where superbacteria can help. While they can’t make the radioactive materials any less radioactive, they can trap them...

The difference between soluble and insoluble uranium can be thought of as the difference between food coloring and pepper. When you drop food coloring into a glass of water, the substance disperses through the water and there is no easy way to re-segregate it from the water. If, on the other hand, you drop a handful of pepper into the water, the pepper does not dissolve. Then, a filter can separate it from the water. Similarly, if bacteria can trap hazardous materials, they’ll never make it into the groundwater.

More at the link, via Not Exactly Rocket Science.  I believe I've read similar accounts in the past about trees cleaning contaminated soil by extracting isotopes from the soil and transferring them to leaves which can be picked up after they fall (but I can't find that link).