Reduction of elemental selenium to selenide: Experiments with anoxic sediments and bacteria that respire Se-oxyanions

Geomicrobiology Journal
By: , and 

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Abstract

A selenite-respiring bacterium, Bacillus selenitireducens, produced significant levels of Se(-II) (as aqueous HSe) when supplied with Se(0). B. selenitireducens was also able to reduce selenite [Se(IV)] through Se(0) to Se(-II). Reduction of Se(0) by B. selenitireducens was more rapid in cells grown on colloidal sulfur [S(0)] or Se(IV) as their electron acceptor than for cell lines grown on fumarate. In contrast, three cultures of selenate-respiring bacteria, Sulfurospirillum barnesiiB. arsenicoselenatis, and Selenihalanaerobacter shriftii either were unable to reduce Se(0) to Se(-II) or had only a very limited capacity to achieve this reduction. Biological reduction of Se(0) to Se(-II) was observed during incubation of estuarine sediment slurries, while no such activity was noted in formalin-killed controls. The majority of the Se(-II) produced was found in the sediments as a solid precipitate of FeSe, rather than in solution as HSe. These results demonstrate that certain anaerobic bacteria have the capacity to reduce Se(0) to Se(-II), providing a possible biological explanation for the occurrence of the selenide species in some sedimentary rocks.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Reduction of elemental selenium to selenide: Experiments with anoxic sediments and bacteria that respire Se-oxyanions
Series title Geomicrobiology Journal
DOI 10.1080/713851163
Volume 20
Issue 6
Year Published 2003
Language English
Publisher Taylor & Francis
Contributing office(s) Toxic Substances Hydrology Program
Description 16 p.
First page 587
Last page 602