GEOC 124 |
| Karen J. Murray, Mylene L. Mozafarzadeh, and Bradley M. Tebo. Scripps Institution of Oceanography, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0202 |
| The long term immobilization of environmental chromium contamination by reduction to Cr(III) may be hindered by the presence Mn oxides, the only known environmental oxidant of Cr(III). Our research focuses on the ability of Mn-oxidizing bacteria to oxidize Cr(III), either directly or through the production of oxidized Mn. Experiments with well-characterized strains of Bacillus and Pseudomonas as well as consortia and isolates from the Black Sea suggest that bacteria may accelerate rates of Cr(III) oxidation over those which would occur abiotically from the bacterially-produced Mn oxides alone. Cr(III) oxidation was decreased in the presence of azide, an inhibitor of enzymatic Mn oxidation, and absent in mutants incapable of Mn(II) oxidation. These results are consistent with the involvement of the Mn(II)-oxidizing enzyme in Cr(III) oxidation, either directly or indirectly via the production of a reactive Mn species. |
|
Poster Session
6:00 PM-9:00 PM, Tuesday, March 30, 2004 Anaheim Convention Center -- Hall A, Poster
Division of Geochemistry |