Superbug Survives Radiation, Eats Toxic Waste
A can of spoiled meat and nuclear waste may appear to have little in common, but the bacterium Deinococcus radiodurans thrives in both environments. This bacterium was discovered in 1956 when it was identified as the culprit in a can of spoiled ground beef thought to be radiation ”sterilized.” Scientists subsequently learned that its extreme radiation resistance enables the microbe to survive doses thousands of times higher than would kill most organisms, including humans. The remarkable DNA-repair processes of D. radiodurans allow it to stitch together flawlessly its own radiation-shattered genome in about 24 hours.
DOE chose this organism for DNA sequencing because of its potential usefulness in cleaning up waste sites containing radiation and toxic chemicals. Its DNA sequence was completely determined in 1999, and scientists now are exploring ways to add genes from other organisms to expand D. radiodurans’ capabilities for removing toxic wastes from contaminated sites. The added genes encode proteins that transform heavy metals to a more benign biomass and allow the concentration of heavy metals and the breakdown of organic solvents such as toluene. Studies into this organism’s remarkable DNA-repair pathways also may help scientists better understand how defects in human cellular processes might lead to the development of cancers.
http://www.ornl.gov/sci/techresources/Human_Genome/publicat/microbial/09super.htmlPretty neat stuff. I am sure wal-mart will be carrying it soon :)
Now that the intricacies of D. radiodurans have been covered, one may explore the possibilities for utilizing the microbe's special skills. At the top of the list for uses of D. radiodurans is bioremediation. Bioremediation is the strategy of using bacteria to feed on or simply degrade dangerous compounds. Although simple in theory, scientists have discovered microbes with an ability to metabolize one toxic substance, only to find that other compounds in a waste mix inhibit the bacterium's growth. D. radiodurans may offer a solution by providing the framework to create a versatile and efficient "superbug." The design of the superbug revolves around equipping D. radiodurans with genes imported from other bacterium already known to degrade dangerous compounds. Though organic pollutants such as trichloroethylene and toluene may be metabolized by specific microbes already known, no known bacterium can actually metabolize uranium, plutonium, and other heavy metals into harmless substances. However, some microbes do possess genes encoding proteins that immobilize metals with which they come in contact. By implementing these genes into the superbug, at least the spread of radioactive elements and other metals could be stifled until other cleanup strategies are available. So, although D. radiodurans may not provide a direct solution for waste treatment, it does provide scientists with a potential alternative.
http://web.umr.edu/~microbio/BIO221_2000/Deinococcus_radiodurans.htmlApplications
Using genetic engineering Deinococcus has been used for bioremediation to consume and digest solvents and heavy metals, even in a highly radioactive site. The bacterial mercuric reductase gene has been cloned from Escherichia coli into Deinococcus to detoxify the ionic mercury frequently found in radioactive waste generated from nuclear weapons manufacture<6>. Those researchers developed a strain of Deinococcus that could detoxify both mercury and toluene in mixed radioactive wastes.
Some have speculated that mechanisms of DNA repair used by D. radiodurans could be incorporated into the genome of higher species as a means of rejuvenation.
http://en.wikipedia.org/wiki/Deinococcus_radiodurans