BERKELEY, CA Heres a pollution-control tip from nature: Deep inside a flooded mine in Wisconsin, scientists from several institutions including the U.S. Department of Energys Lawrence Berkeley National Laboratory (Berkeley Lab) have discovered a world in which bacteria emit proteins that sweep up metal nanoparticles into immobile clumps. Their finding may lead to innovative ways to remediate subsurface metal toxins.
The research, which appears in the June 15, 2007 issue of the journal Science, reveals that the proteins travel far from the microbes that produce them, and then amass metal nanoparticles into piles that are too large to be swept away by underground currents. Precisely how and why the bacteria undertake this bit of housecleaning remains a mystery, but it suggests that proteins could play a key role in bioremediation strategies designed to trap harmful metals such as arsenic, lead, uranium, and plutonium.
We have found, in the environment, that cells release proteins and polypeptides which promote the aggregation of nanoparticulate metals, says John Moreau, lead author of the study and a former PhD student in UC Berkeleys Department of Earth and Planetary Sciences. The intriguing discovery that biomolecules may shape nanoparticles into larger aggregates, which reduces the nanoparticles mobility, could have significant implications for bioremediation.
Moreau conducted the research under the guidance of Jill Banfield, a principal investigator in the Geochemistry Department of Berkeley Labs Earth Sciences Division, and a UC Berkeley professor in the Department of Earth and Planetary Sciences and in the Department of Environmental Science, Policy and Management. Other scientists involved in the research include Michael Martin and Benjamin Gilbert of Berkeley Lab, and Peter Weber and Ian Hutcheon of Lawrence Livermore National Laboratory.