Based on laboratory studies, Georgia Institute of Technology researchers report promising results using bacterial species from three genera isolated from subsurface soils collected at a U.S. Department of Energy (DOE) Field Research Center site in Oak Ridge, Tenn. Researchers conducted preliminary screenings of many bacterial isolates and found several candidate strains that released inorganic phosphate after hydrolyzing an organo-phosphate source the researchers provided.

The bioremediation research project, funded for three years by DOE's Environmental Remediation Sciences Division, is in its early stages. Research team member Melanie Beazley, a Ph.D. student in the Georgia Tech School of Earth and Atmospheric Sciences, will present preliminary findings on March 30 at the 231st American Chemical Society National Meeting in Atlanta.

"These organisms release phosphate into the medium, but the precipitation (of uranium phosphate) occurs chemically," explained Assistant Professor of Earth and Atmospheric Sciences Martial Taillefert, co-director of the study. "That is the biomineralization of uranium and the novelty of this approach."

The process begins when the bacteria from the genera Rhanella, Bacillus and possibly Arthrobacter degrade an organo-phosphate compound such as glycerol-3-phosphate (G3P) or phytic acid (IP6), which can be present in subsurface soils.

"During their growth, the organisms liberate phosphate they derive from the organo-phosphate compound," said project co-director Patricia Sobecky, an associate professor of biology. "The free phosphate is released to the surrounding media, which is a solution in the lab. Then we conduct assays to see how much uranium is min
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Contact: Jane Sanders
jane.sanders@edi.gatech.edu
404-894-2214
Georgia Institute of Technology Research News
30-Mar-2006