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Self-standing Electrochemical Set-up to Enrich Anode-respiring Bacteria On-site
Published on: July 24, 2018
A microbial arsenic cycle in a salt-saturated, extreme environment
Ronald S Oremland1, Thomas R Kulp, Jodi Switzer Blum
1U.S. Geological Survey, ms 480, 345 Middlefield Road, Menlo Park, CA 94025, USA. roremlan@usgs.gov
Science (New York, N.Y.)
|May 28, 2005
Summary
Searles Lake
Area of Science:
- Environmental science
- Geochemistry
- Microbiology
Background:
- Searles Lake contains alkaline, arsenic-rich brines.
- Arsenic speciation varies with sediment depth, from arsenate [As(V)] to arsenite [As(III)].
Purpose of the Study:
- Investigate arsenic biogeochemical cycling in Searles Lake.
- Identify microbial roles in arsenic transformations.
Main Methods:
- Incubation of anoxic and aerobic sediment slurries.
- Measurement of arsenic speciation and microbial activity.
- Isolation and characterization of arsenic-respiring bacteria.
Main Results:
- Dissimilatory As(V)-reductase activity was stimulated by H2 or sulfide in anoxic slurries.
- As(III)-oxidase activity was rapid in aerobic slurries.
- An anaerobic, haloalkaliphilic bacterium utilizing As(V) respiration was isolated.
Conclusions:
- A complete arsenic biogeochemical cycle exists in Searles Lake.
- Inorganic electron donors contribute to driving this cycle.
- Microbial processes are key to arsenic transformation in this environment.
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