HR: 1340h
AN: B33A-0863    [Abstracts]
TI: Arsenite-Dependent Anoxygenic Photosynthesis by Bacteria from Mono Lake, California
AU: * Hollibaugh, J T
EM: aquadoc@uga.edu
AF: Dept Marine Sciences, University of Georgia, Athens, GA 30602-3636, United States
AU: Budinoff, C R
EM: cbud@uga.edu
AF: Dept Marine Sciences, University of Georgia, Athens, GA 30602-3636, United States
AB: Chemolithoautotrophic growth of bacteria capable of using inorganic arsenic compounds is well documented. Energy conservation and carbon fixation have been demonstrated in both arsenite oxidizers and arsenate reducers from many bacterial lineages under both aerobic and anaerobic conditions. However, phototrophic growth using reduced arsenic as an electron donor has not been described. Here we report the light-dependent oxidation of arsenite to arsenate, coupled with autotrophic growth, by an enrichment culture of bacteria from Mono Lake, California. The culture is dominated by a phototrophic member of the Ectothiorhodospiraceae that is >99% similar to Ectothiorhodospira sp. (strain Borgoria Red). It also contains an uncultured member of the Bacteriodetes and another member of the Ectothiorhodospiraceae that is 96% similar to Alkalilimnicola erhlichii. The bacteria grow more slowly and clump when grown on arsenite versus sulfide or thiosulfate. Scanning electron micrographs reveal that they are closely associated and enmeshed in an organic matrix.
DE: 0404 Anoxic and hypoxic environments (4802, 4834)
DE: 0448 Geomicrobiology
DE: 0465 Microbiology: ecology, physiology and genomics (4840)
DE: 0471 Oxidation/reduction reactions (4851)
DE: 0489 Trace element cycling (4875)
SC: Biogeosciences [B]
MN: 2007 Fall Meeting