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Desulfonatronospira thiodismutans ASO3-1
   
   
 

Cell morphology of Desulfonatronospira thiodismutans grown at 2M sodium and pH 10. Cultures grown with sulfite alone (a), or with lactate as electron donor and carbon source, and sulfite as electron acceptor (b). Photo credit: Dimitry Yu Sorokin

Desulfonatronospira thiodismutans belongs to a novel lineage within the Desulfohalobiaceae (Deltaproteobacteria, Bacteria) most closely related to Desulfonatronovibrio hydrogenovorans. The bacterium was isolated from a mixture of sediment samples of different soda lakes in South Eastern Siberia, Russia. Desulfonatronospira thiodismutans is a facultatively autotrophic bacterium with two types of reductive metabolisms: (1) inorganic fermentation of sulfite and thiosulfate, and (2) reduction of sulfate, sulfite and thiosulfate in the presence of hydrogen and simple organic electron donors; acetate can be used only as a carbon source. It is the first example of an extremely natronophilic (soda-loving) sulfate-reducing bacterium growing at sodium concentrations between 1.5 and 4M, and a pH between 8.3 and 10.5. We have chosen this organism for whole genome sequencing because of its industrial relevance in the sustainable removal of sulfur compounds from waste streams and energy carriers. In this respect it contributes to the Bioremediation mission of the Department of Energy. Apart from society-driven research, the genome sequences will also be the start for curiosity-driven research, i.e., to obtain a comprehensive understanding of the mechanisms by which the species adapt to extreme haloalkaline conditions.

References

Sorokin, D. Yu., T.P. Tourova, A.M. Henstra, A.J.M. Stams, E.A. Galinski and G. Muyzer. 2008. Sulfidogenesis under extremely haloalkaline conditions by Desulfonatronospira thiodismutans ge. nov., sp. nov. and Desulfonatronospira delicata sp. nov. - a novel ineage of Deltaproteobacteria from hypersaline soda lakes. Microbiology 154: 1444-1453.