HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Siddique, T. Articles by Zhang, Y. Search for Related Content PubMed PubMed Citation Articles by Siddique, T. Articles by Zhang, Y. GeoRef GeoRef Citation Agricola Articles by Siddique, T. Articles by Zhang, Y. Related Collections Microbial Processes Bioremediation and Biodegradation Other Environmental Contamination

TECHNICAL REPORTS

Bioremediation and Biodegradation

Bacterial Reduction of Selenium in Coal Mine Tailings Pond Sediment

^a Environmental Science and Engineering, Univ. of Northern British Columbia, 3333 University Way, Prince George, BC V2N 4Z9 Canada
^b Canada Research Chair–Soil and Environmental Sciences, Univ. of Northern British Columbia, 3333 University Way, Prince George, BC V2N 4Z9 Canada
^c Dep. of Environmental Sciences, Univ. of California, Riverside, CA 92521 USA. T. Siddique, present address, Dep. of Biological Sciences, University of Alberta, Edmonton, AB, Canada T6G 2E9

^* Corresponding author (arocenaj{at}unbc.ca)

Received for publication September 6, 2006. Sediment from a storage facility for coal tailings solids was assessed for its capacity to reduce selenium (Se) by native bacterial community. One Se⁶⁺–reducing bacterium Enterobacter hormaechei (Tar11) and four Se⁴⁺–reducing bacteria, Klebsiella pneumoniae (Tar1), Pseudomonas fluorescens (Tar3), Stenotrophomonas maltophilia (Tar6), and Enterobacter amnigenus (Tar8) were isolated from the sediment. Enterobacter hormaechei removed 96% of the added Se⁶⁺ (0.92 mg L^–1) from the effluents when Se⁶⁺ was determined after 5 d of incubation. Analysis of the red precipitates showed that Se⁶⁺ reduction resulted in the formation of spherical particles (<1.0 µm) of Se⁰ as observed under scanning electron microscope (SEM) and confirmed by EDAX. Selenium speciation was performed to examine the fate of the added Se⁶⁺ in the sediment with or without addition of Enterobacter hormaechei cells. More than 99% of the added Se⁶⁺ (2.5 mg L^–1) was transformed in the nonsterilized sediment (without Enterobacter hormaechei cells) as well as in the sterilized (heat-killed) sediment (with Enterobacter hormaechei cells). The results of this study suggest that the lagoon sediments at the mine site harbor Se⁶⁺– and Se⁴⁺–reducing bacteria and may be important sinks for soluble Se (Se⁶⁺ and Se⁴⁺). Enterobacter hormaechei isolated from metal-contaminated sediment may have potential application in removing Se from industrial effluents.