Microbial oxidation of elemental selenium in soil slurries and bacterial cultures

Journal Article · Tue Dec 01 04:00:00 EST 1998 · Environmental Science and Technology

DOI:https://doi.org/10.1021/es970940s· OSTI ID:302219

Dowdle, P R; Oremland, R S ^[1]

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1. Geological Survey, Menlo Park, CA (United States)

The microbial oxidation of elemental selenium [Se(0)] was studied by employing {sup 75}Se(0) as a tracer. Live, oxic soil slurries demonstrated a linear production of mostly Se(IV), with the formation of smaller quantities of Se(VI). Production of both Se(IV) and Se(VI) was inhibited by autoclaving, formalin, antibiotics, azide, and 2,4-dinitrophenol, thereby indicating the involvement of microbes. Oxidation of Se(0) in slurries was enhanced by addition of acetate, glucose, or sulfide, which implied involvement of chemoheterotrophs as well as chemoautotrophic thiobacilli. Cultures of Thiobacillus ASN-1, Leptothrix MnB1, and a heterotrophic soil enrichment all oxidized Se(0) with Se(VI) observed as the major product rather than Se(IV). This indicated that microbial oxidation in soils is partly constrained by the adsorption of Se(IV) onto soil surfaces. Rate constants for unamended soil slurry Se(0) oxidation ranged from 0.0009 to 0.0117 day{sup {minus}1} which were 3--4 orders of magnitude lower than those reported for dissimilatory Se(VI) reduction in organic-rich, anoxic sediments.

• OSTI ID: 302219
• Journal Information: Environmental Science and Technology, Journal Name: Environmental Science and Technology Journal Issue: 23 Vol. 32; ISSN ESTHAG; ISSN 0013-936X
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
BACTERIA
BIODEGRADATION
REMEDIAL ACTION
SELENIUM
SLURRIES
SOILS