title: Elemental sulfur and acetate can support life of a novel strictly anaerobic haloarchaeon.
abstract: Archaea domain is comprised of many versatile taxa that often colonize extreme habitats. Here, we report the discovery of strictly anaerobic extremely halophilic euryarchaeon, capable of obtaining energy by dissimilatory reduction of elemental sulfur using acetate as the only electron donor and forming sulfide and CO2 as the only products. This type of respiration has never been observed in hypersaline anoxic habitats and is the first example of such metabolic capability in the entire Archaea domain. We isolated and cultivated these unusual organisms, selecting one representative strain, HSR2, for detailed characterization. Our studies including physiological tests, genome sequencing, gene expression, metabolomics and [(14)C]-bicarbonate assimilation assays revealed that HSR2 oxidized acetate completely via the tricarboxylic acid cycle. Anabolic assimilation of acetate occurred via activated glyoxylate bypass and anaplerotic carboxylation. HSR2 possessed sulfurtransferase and an array of membrane-bound polysulfide reductase genes, all of which were expressed during the growth. Our findings suggest the biogeochemical contribution of haloarchaea in hypersaline anoxic environments must be reconsidered.
authors.affiliation: Winogradsky Institute of Microbiology, Russian Academy of Sciences, Moscow, Russia.|Department of Biotechnology, Delft University of Technology, Delft, The Netherlands.
authors.forename: Dimitry Y
authors.initials: DY
authors.lastname: Sorokin
authors.affiliation: Winogradsky Institute of Microbiology, Russian Academy of Sciences, Moscow, Russia.
authors.forename: Ilya V
authors.initials: IV
authors.lastname: Kublanov
authors.affiliation: Winogradsky Institute of Microbiology, Russian Academy of Sciences, Moscow, Russia.
authors.forename: Sergei N
authors.initials: SN
authors.lastname: Gavrilov
authors.affiliation: Center for Metabolomics and Bioanalysis, Faculty of Pharmacy, CEU San Pablo University, Boadilla del Monte, Spain.
authors.forename: David
authors.initials: D
authors.lastname: Rojo
authors.affiliation: Sub-department of Environmental Technology, Wageningen University, Wageningen, The Netherlands.|Wetsus, Centre of Excellence for Sustainable Water Technology, Leeuwarden, The Netherlands.
authors.forename: Pawel
authors.initials: P
authors.lastname: Roman
authors.affiliation: School of Biological Sciences, Bangor University, Gwynedd, UK.
authors.forename: Peter N
authors.initials: PN
authors.lastname: Golyshin
authors.affiliation: Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL, USA.
authors.forename: Vladlen Z
authors.initials: VZ
authors.lastname: Slepak
authors.affiliation: Institute for Coastal Marine Environment, CNR, Messina, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Smedile
authors.affiliation: Institute of Catalysis, CSIC, Madrid, Spain.
authors.forename: Manuel
authors.initials: M
authors.lastname: Ferrer
authors.affiliation: Institute for Coastal Marine Environment, CNR, Messina, Italy.
authors.forename: Enzo
authors.initials: E
authors.lastname: Messina
authors.affiliation: Institute for Coastal Marine Environment, CNR, Messina, Italy.
authors.forename: Violetta
authors.initials: V
authors.lastname: La Cono
authors.affiliation: Institute for Coastal Marine Environment, CNR, Messina, Italy.
authors.forename: Michail M
authors.initials: MM
authors.lastname: Yakimov
mesh_terms: D000085:Acetates / Q000378:metabolism*; D000693:Anaerobiosis; D001105:Archaea / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D019843:Archaeal Proteins / Q000378:metabolism; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000378:metabolism; D013440:Sulfides / Q000378:metabolism; D013455:Sulfur / Q000378:metabolism*
chemical_list: D000085:Acetates; D019843:Archaeal Proteins; D013440:Sulfides; D013455:Sulfur; D010088:Oxidoreductases; C074883:polysulfide reductase