Comment on "Arsenic (III) fuels anoxygenic photosynthesis in hot spring biofilms from Mono Lake, California".
Kulp et al. (Reports, 15 August 2008, p. 967) described a bacterium able to photosynthetically oxidize arsenite [As(III)] via arsenate [As(V)] reductase functioning in reverse. Based on their phylogenetic analysis of As(V) reductase, they proposed that this enzyme was responsible for the anaerobic oxidation of As(III) in the Archean. We challenge this proposition based on paleogeochemical, bioenergetic, and phylogenetic arguments.
Schoepp-Cothenet
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B
Bioénergétique et Ingénierie des Protéines, IFR88, CNRS, 13402 Marseille, France. schoepp@ifr88.cnrs-mrs.fr
Duval
S
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Santini
J M
JM
Nitschke
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W
D053502:Arsenate Reductases / Q000378:metabolism*; D018053:Arsenites / Q000378:metabolism*; D001419:Bacteria / Q000378:metabolism*; D018441:Biofilms; D002140:California; D045482:Hot Springs / Q000382:microbiology*; D010084:Oxidation-Reduction; D010788:Photosynthesis; D010802:Phylogeny
D018053:Arsenites; D053502:Arsenate Reductases; C015001:arsenite