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

ABSTRACT: 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(-1), suggesting that iron reduction has occurred recently. The maximum concentrations of dissolved Fe(II) in interstitial water (41 mg liter(-1)) occurred 10 to 15 cm beneath the sediment-water interface, suggesting that sulfidogenesis may

SUBMITTER: Cummings DE 

PROVIDER: S-EPMC91799 | biostudies-literature | 2000 Jan

REPOSITORIES: biostudies-literature