Metal Reduction at Low pH by a Desulfosporosinus species: Implications for the Biological Treatment of Acidic Mine Drainage
Abstract:We isolated an acid-tolerant sulfate-reducing bacterium, GBSRB4.2, from coal mine-derived acidic mine drainage (AMD)-derived sediments. Sequence analysis of partial 16S rRNA gene of GBSRB4.2 revealed that it was affiliated with the genus Desulfosporosinus. GBSRB4.2 reduced sulfate, Fe(III) (hydr)oxide, Mn(IV) oxide, and U(VI) in acidic solutions (pH 4.2). Sulfate, Fe(III), and Mn(IV) but not U(VI) bioreduction led to an increase in the pH of acidic solutions and concurrent hydrolysis and precipitation of dissolved Al3+. Reduction of Fe(III), Mn(IV), and U(VI) in sulfate-free solutions revealed that these metals are enzymatically reduced by GBSRB4.2. GBSRB4.2 reduced U(VI) in groundwater from a radionuclide-contaminated aquifer more rapidly at pH 4.4 than at pH 7.1, possibly due to the formation of poorly bioreducible Ca-U(VI)-CO3 complexes in the pH 7.1 groundwater.
Document Type: Research Article
Affiliations: 1: Department of Geology and Environmental Science, The University of Akron, Akron, OH,Department of Civil and Environmental Engineering, The Pennsylvania State University, University Park, Pennsylvania, USA 2: Department of Civil and Environmental Engineering, The Pennsylvania State University, University Park, Pennsylvania, USA 3: ARCADIS U.S. Inc., USA 4: Department of Crop and Soil Sciences, The Pennsylvania State University, Pennsylvania, USA
Publication date: March 1, 2009