pure and mixed cultures of iron(III) reducers (FeRB), such as. Geobacter spp., sulfate ..... tubes, color change in FeRB tubes, and production of black Fe(II) sulfide.
APPLIED AND ENVIRONMENTAL MICROBIOLOGY, June 2008, p. 3718–3729 0099-2240/08/$08.00⫹0 doi:10.1128/AEM.02308-07 Copyright © 2008, American Society for Microbiology. All Rights Reserved.
Vol. 74, No. 12
Microbial Communities in Contaminated Sediments, Associated with Bioremediation of Uranium to Submicromolar Levels䌤 Erick Cardenas,1 Wei-Min Wu,2 Mary Beth Leigh,1† Jack Carley,3 Sue Carroll,3 Terry Gentry,3‡ Jian Luo,2# David Watson,3 Baohua Gu,3 Matthew Ginder-Vogel,2§ Peter K. Kitanidis,2 Philip M. Jardine,3 Jizhong Zhou,3¶ Craig S. Criddle,2 Terence L. Marsh,1* and James M. Tiedje1* Center for Microbial Ecology, Michigan State University, East Lansing, Michigan 488241; Department of Civil and Environmental Engineering, Stanford University, Stanford, California 94305-40202; and Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 378313 Received 12 October 2007/Accepted 18 April 2008
Microbial enumeration, 16S rRNA gene clone libraries, and chemical analysis were used to evaluate the in situ biological reduction and immobilization of uranium(VI) in a long-term experiment (more than 2 years) conducted at a highly uranium-contaminated site (up to 60 mg/liter and 800 mg/kg solids) of the U.S. Department of Energy in Oak Ridge, TN. Bioreduction was achieved by conditioning groundwater above ground and then stimulating growth of denitrifying, Fe(III)-reducing, and sulfate-reducing bacteria in situ through weekly injection of ethanol into the subsurface. After nearly 2 years of intermittent injection of ethanol, aqueous U levels fell below the U.S. Environmental Protection Agency maximum contaminant level for drinking water and groundwater (
