Iodide Accumulation by Aerobic Bacteria Isolated from Subsurface Sediments of a super(129)I-Contaminated Aquifer at the Savannah River Site, South Carolina

• Published in: Applied and Environmental Microbiology 2011-03, Vol.77 (6), p.2153-2153
• Main Authors: Li, Hsiu-Ping, Brinkmeyer, Robin, Jones, Whitney L, Zhang, Saijin, Xu, Chen, Schwehr, Kathy A, Santschi, Peter H, Kaplan, Daniel I, Yeager, Chris M
• Format: Article
• Language: English
• Subjects: Bacillus mycoides; Flexibacter; Kitasatospora; Ralstonia; Streptomyces
• ISSN: 0099-2240; 1098-6596
• DOI: 10.1128/AEM.02164-10

super(129)I is of major concern because of its mobility in the environment, excessive inventory, toxicity (it accumulates in the thyroid), and long half-life ( similar to 16 million years). The aim of this study was to determine if bacteria from a super(129)I-contaminated oxic aquifer at the F area of the U.S. Department of Energy's Savannah River Site, SC, could accumulate iodide at environmentally relevant concentrations (0.1 mu M I super(-)). Iodide accumulation capability was found in 3 out of 136 aerobic bacterial strains isolated from the F area that were closely related to Streptomyces/Kitasatospora spp., Bacillus mycoides, and Ralstonia/Cupriavidus spp. Two previously described iodide-accumulating marine strains, a Flexibacter aggregans strain and an Arenibacter troitsensis strain, accumulated 2 to 50% total iodide (0.1 mu M), whereas the F-area strains accumulated just 0.2 to 2.0%. Iodide accumulation by FA-30 was stimulated by the addition of H sub(2)O sub(2), was not inhibited by chloride ions (27 mM), did not exhibit substrate saturation kinetics with regard to I super(-) concentration (up to 10 mu M I super(-)), and increased at pH values of