Reductive precipitation of gold by dissimilatory Fe(III)-reducing bacteria and archaea.

Reductive Presipitation of Gold by Dissimilatory Fe(III)-Reducing Bacteria and Archaea

279. Dissimilatory Fe(III)- and Mn(IV)-Reducing Prokaryotes

Dissimilatory Fe(III) reduction is the process in which microorganisms transfer electrons to external ferric iron [Fe(III)], reducing it to ferrous iron [Fe(II)] without assimilating the iron. A wide phylogenetic diversity of microorganisms, including archaea as well as bacteria, are capable of dissimilatory Fe(III) reduction. Most microorganisms that reduce Fe(III) also can transfer electrons ...

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

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 ecologi...

Microbial Respiration and Precipitation of Arsenic

This dissertation explores the biogeochemistry, physiology, molecular biology, and environmental impact of dissimilatory arsenate reducing bacteria. A new species, Desulfotomaculum auripigmentum strain OREX-4, was found to precipitate amorphous arsenic trisulfide (AS2S3)both intraand extracellularly. Intracellular precipitation of AS2S3nucleates precipitation in the bulk milieu, and results fro...

Dissolution of Arsenic Minerals Mediated by Dissimilatory Arsenate Reducing Bacteria: Estimation of the Physiological Potential for Arsenic Mobilization

The aim of this study was characterization of the isolated dissimilatory arsenate reducing bacteria in the context of their potential for arsenic removal from primary arsenic minerals through reductive dissolution. Four strains, Shewanella sp. OM1, Pseudomonas sp. OM2, Aeromonas sp. OM4, and Serratia sp. OM17, capable of anaerobic growth with As (V) reduction, were isolated from microbial mats ...