Molecular determination of arsenate respiring bacteria in estuarine sediments and groundwater
- UNCW Author/Contributor (non-UNCW co-authors, if there are any, appear on document)
- Holly G. Oates (Creator)
- Institution
- The University of North Carolina Wilmington (UNCW )
- Web Site: http://library.uncw.edu/
- Advisor
- Bongkeun Song
Abstract: Arsenic is a well-known metalloid and carcinogen with both natural and
anthropogenic origins. Arsenic occurs naturally in the environment as two primary
inorganic forms: arsenate [As(V)] and arsenite [As(III)]. Microbes mediate the presence
and quantity of these two arsenic species through oxidation and reduction processes.
Dissimilatory As(V) respiring bacteria (DARB) contain As(V) respiratory reductase (arrA)
genes and reduce As(V) to As(III), therefore enhancing the solubility of arsenic. Thus,
the detection of the genes encoding As(V) respiratory reductases could interpret the
presence and involvement of DARB in arsenic mobilization. With water samples
collected from two NC wells, and sediment collected from Shem Creek, South Carolina
the presence of DARB using arrA genes as genetic markers were determined and the
As(V) reduction activities were monitored via enrichment culture techniques. Based on
molecular analysis, the DARB in the NC wells are closely related to Geobacter
uraniumreducens while those in Shem Creek sediments are related to
Desulfosporosinus Y5. Anaerobic enrichment cultures were established with NC well
water and Shem Creek sediment to determine the rate of As(V) reduction. The rates for
all of the sites involved showed that the DARB could have a significant impact on the
arsenic levels in the environment. Thus, this study demonstrates the presence and
diversity of DARB in these environments and their contributions to the arsenic
contamination in NC residential drinking water wells, and in the Shem Creek estuary.
Molecular determination of arsenate respiring bacteria in estuarine sediments and groundwater
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Created on 1/1/2009
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Additional Information
- Publication
- Thesis
- A Thesis Submitted to the University of North Carolina at Wilmington in Partial Fulfillment of the Requirement for the Degree of Masters of Science
- Language: English
- Date: 2009
- Keywords
- Arsenic compounds--Environmental aspects, Groundwater--Microbiology
- Subjects
- Arsenic compounds -- Environmental aspects
- Groundwater -- Microbiology