Evidence for microbial Fe(III) reduction in anoxic, mining-impacted lake sediments (Lake Coeur d'Alene, Idaho)

Journal Article · Sat Jan 01 04:00:00 EST 2000 · Applied and Environmental Microbiology

DOI:https://doi.org/10.1128/AEM.66.1.154-162.2000· OSTI ID:20026710

Cummings, D E; March, A W; Bostick, B; Spring, S; Caccavo, F Jr; Fendorf, S; Rosenzweig, R F

Mining-impacted sediments of Lake Coeur d'Alene, Idaho, contain more than 10% metals on a dry weight basis, approximately 80% of which is iron. Since iron (hydr)oxides adsorb toxic, ore-associated elements, such as arsenic, iron (hydr)oxide reduction may in part control the mobility and bioavailability of these elements. Geochemical and microbiological data were collected to examine the ecological role of dissimilatory Fe(III)-reducing bacteria in this habitat. The concentration of mild-acid-extractable Fe(II) increased with sediment depth up to 50 g kg{sup {minus}1}, suggesting that iron reduction has occurred recently. The maximum concentrations of dissolved Fe(II) in interstitial water (41 mg liter{sup {minus}1}) occurred 10 to 15 cm beneath the sediment-water interface, suggesting that sulfidogenesis may not be the predominant terminal electron-accepting process in this environment and that dissolved Fe(II) arises from biological reductive dissolution of iron (hydr)oxides. The concentration of sedimentary magnetite (Fe{sub 3}O{sub 4}), a common product of bacterial Fe(III) hydroxide reduction, was as much as 15.5 g kg{sup {minus}1}. Most-probable-number enrichment cultures revealed that the mean density of Fe(III)-reducing bacteria was 8.3 x 10{sup 5} cells g (dry weight) of sediment{sup {minus}1}. Two new strains of dissimilatory Fe(III)-reducing bacteria were isolated from surface sediments. Collectively, the results of this study support the hypothesis that dissimilatory reduction of iron has been and continues to be an important biogeochemical process in the environment examined.

• Research Organization: Univ. of Idaho, Moscow, ID (US)
• Sponsoring Organization: National Science Foundation; US Department of Energy
• DOE Contract Number: FG03-97ER62481
• OSTI ID: 20026710
• Journal Information: Applied and Environmental Microbiology, Journal Name: Applied and Environmental Microbiology Journal Issue: 1 Vol. 66; ISSN AEMIDF; ISSN 0099-2240
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
ANOXIA
ARSENIC
BACTERIA
BIODEGRADATION
BIOGEOCHEMISTRY
IDAHO
IRON
LAKES
REDUCTION
SEDIMENTS
WATER CHEMISTRY
WATER POLLUTION CONTROL