Dissimilatory arsenate and sulfate reduction in sediments of two hypersaline, arsenic-rich soda lakes: Mono and Searles Lakes, California
Links
- More information: Publisher Index Page (via DOI)
- Open Access Version: External Repository
- Download citation as: RIS | Dublin Core
Abstract
A radioisotope method was devised to study bacterial respiratory reduction of arsenate in sediments. The following two arsenic-rich soda lakes in California were chosen for comparison on the basis of their different salinities: Mono Lake (∼90 g/liter) and Searles Lake (∼340 g/liter). Profiles of arsenate reduction and sulfate reduction were constructed for both lakes. Reduction of [73As]arsenate occurred at all depth intervals in the cores from Mono Lake (rate constant [k] = 0.103 to 0.04 h−1) and Searles Lake (k = 0.012 to 0.002 h−1), and the highest activities occurred in the top sections of each core. In contrast, [35S]sulfate reduction was measurable in Mono Lake (k = 7.6 ×104 to 3.2 × 10−6 h−1) but not in Searles Lake. Sediment DNA was extracted, PCR amplified, and separated by denaturing gradient gel electrophoresis (DGGE) to obtain phylogenetic markers (i.e., 16S rRNA genes) and a partial functional gene for dissimilatory arsenate reduction (arrA). The amplified arrA gene product showed a similar trend in both lakes; the signal was strongest in surface sediments and decreased to undetectable levels deeper in the sediments. More arrA gene signal was observed in Mono Lake and was detectable at a greater depth, despite the higher arsenate reduction activity observed in Searles Lake. A partial sequence (about 900 bp) was obtained for a clone (SLAS-3) that matched the dominant DGGE band found in deeper parts of the Searles Lake sample (below 3 cm), and this clone was found to be closely related to SLAS-1, a novel extremophilic arsenate respirer previously cultivated from Searles Lake.
Publication type | Article |
---|---|
Publication Subtype | Journal Article |
Title | Dissimilatory arsenate and sulfate reduction in sediments of two hypersaline, arsenic-rich soda lakes: Mono and Searles Lakes, California |
Series title | Applied and Environmental Microbiology |
DOI | 10.1128/AEM.01066-06 |
Volume | 72 |
Issue | 10 |
Year Published | 2006 |
Language | English |
Publisher | ASM |
Contributing office(s) | Toxic Substances Hydrology Program |
Description | 13 p. |
First page | 6514 |
Last page | 6526 |
Google Analytic Metrics | Metrics page |