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Arsenite as an electron donor for anoxygenic photosynthesis: Description of three strains of Ectothiorhodospria from Mono Lake, California, and Big Soda Lake, Nevada

December 26, 2016

Three novel strains of photosynthetic bacteria from the family Ectothiorhodospiraceae were isolated from soda lakes of the Great Basin Desert, USA by employing arsenite (As(III)) as the sole electron donor in the enrichment/isolation process. Strain PHS-1 was previously isolated from a hot spring in Mono Lake, while strain MLW-1 was obtained from Mono Lake sediment, and strain BSL-9 was isolated from Big Soda Lake. Strains PHS-1, MLW-1, and BSL-9 were all capable of As(III)-dependent growth via anoxygenic photosynthesis and contained homologs of arxA, but displayed different phenotypes. Comparisons were made with three related species: Ectothiorhodospira shaposhnikovii DSM 2111, Ectothiorhodospira shaposhnikovii DSM 243T, and Halorhodospira halophila DSM 244. All three type cultures oxidized arsenite to arsenate but did not grow with As(III) as the sole electron donor. DNA–DNA hybridization indicated that strain PHS-1 belongs to the same species as Ect. shaposhnikovii DSM 2111 (81.1% sequence similarity), distinct from Ect. shaposhnikovii DSM 243T (58.1% sequence similarity). These results suggest that the capacity for light-driven As(III) oxidation is a common phenomenon among purple photosynthetic bacteria in soda lakes. However, the use of As(III) as a sole electron donor to sustain growth via anoxygenic photosynthesis is confined to novel isolates that were screened for by this selective cultivation criterion.

Citation Information

Publication Year 2017
Title Arsenite as an electron donor for anoxygenic photosynthesis: Description of three strains of <i>Ectothiorhodospria</i> from Mono Lake, California, and Big Soda Lake, Nevada
DOI 10.3390/life7010001
Authors Shelley McCann, Alison Boren, Jaime Hernandez-Maldonado, Brendon Stoneburner, Chad W Saltikov, John F. Stolz, Ronald S. Oremland
Publication Type Article
Publication Subtype Journal Article
Series Title Life Sciences
Index ID 70181011
Record Source USGS Publications Warehouse
USGS Organization National Research Program - Western Branch

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