Arsenic as an energy source for microbial growth. (Invited)
Abstract
Arsenic, although known for millenia to be a potent poison, can also constitute the basis for energy metabolism by a number of Bacteria and Archaea. Hence, the oxyanion arsenate [As(V)] can serve as a respiratory electron acceptor for the growth of anaerobes, resulting in the accumulation of arsenite [As(III)]. Conversely, As(III) can serve as an electron donor for the growth of aerobic and anaerobic (e.g., nitrate-respiring) chemoautotrophs, as well as photoautotrophs that grow via anoxygenic photosynthesis. Collectively, these microbes carry out these redox reactions between the +3 and +5 oxidation states that have profound importance for the mobility of As in the environment, and perhaps for the pattern of microbial evolution on Earth. I will focus upon the occurrence of these microbes in extreme environments that are rich in naturally-occurring arsenic.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2009
- Bibcode:
- 2009AGUFM.B32B..01O
- Keywords:
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- 0414 BIOGEOSCIENCES / Biogeochemical cycles;
- processes;
- and modeling;
- 0448 BIOGEOSCIENCES / Geomicrobiology;
- 0456 BIOGEOSCIENCES / Life in extreme environments;
- 0465 BIOGEOSCIENCES / Microbiology: ecology;
- physiology and genomics