title: Extremophile microbiomes in acidic and hypersaline river sediments of Western Australia.
abstract: We investigated the microbial community compositions in two sediment samples from the acidic (pH ∼3) and hypersaline (>4.5% NaCl) surface waters, which are widespread in Western Australia. In West Dalyup River, large amounts of NaCl, Fe(II) and sulfate are brought by the groundwater into the surface run-off. The presence of K-jarosite and schwertmannite minerals in the river sediments suggested the occurrence of microbial Fe(II) oxidation because chemical oxidation is greatly reduced at low pH. 16S rRNA gene diversity analyses revealed that sequences affiliated with an uncultured archaeal lineage named Aplasma, which has the genomic potential for Fe(II) oxidation, were dominant in both sediment samples. The acidophilic heterotrophs Acidiphilium and Acidocella were identified as the dominant bacterial groups. Acidiphilium strain AusYE3-1 obtained from the river sediment tolerated up to 6% NaCl at pH 3 under oxic conditions and cells of strain AusYE3-1 reduced the effects of high salt content by forming filamentous structure clumping as aggregates. Neither growth nor Fe(III) reduction by strain AusYE3-1 was observed in anoxic salt-containing medium. The detection of Aplasma group as potential Fe(II) oxidizers and the inhibited Fe(III)-reducing capacity of Acidiphilium contributes to our understanding of the microbial ecology of acidic hypersaline environments.
authors.affiliation: Chair of Aquatic Geomicrobiology, Friedrich Schiller University Jena, Jena, Germany.|The German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany.
authors.forename: Shipeng
authors.identifier: http://orcid.org/0000-0002-1817-0417
authors.initials: S
authors.lastname: Lu
authors.affiliation: Department of Hydrology, University of Bayreuth, Bayreuth, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Peiffer
authors.affiliation: The German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany.
authors.forename: Cassandre Sara
authors.initials: CS
authors.lastname: Lazar
authors.affiliation: School of Civil, Environmental and Mining Engineering, The University of Western Australia, Crawley, Australia.
authors.forename: Carolyn
authors.initials: C
authors.lastname: Oldham
authors.affiliation: Department of River Ecology, Helmholtz Centre for Environmental Research-UFZ, Magdeburg, Germany.
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Neu
authors.affiliation: Institute of Physical Chemistry and Abbe School of Photonics, Friedrich Schiller University Jena, Jena, Germany.
authors.forename: Valerian
authors.initials: V
authors.lastname: Ciobota
authors.affiliation: Department of Hydrology, University of Bayreuth, Bayreuth, Germany.
authors.forename: Olga
authors.initials: O
authors.lastname: Näb
authors.affiliation: School of Civil, Environmental and Mining Engineering, The University of Western Australia, Crawley, Australia.
authors.forename: Adam
authors.initials: A
authors.lastname: Lillicrap
authors.affiliation: Institute of Physical Chemistry and Abbe School of Photonics, Friedrich Schiller University Jena, Jena, Germany.
authors.forename: Petra
authors.initials: P
authors.lastname: Rösch
authors.affiliation: Institute of Physical Chemistry and Abbe School of Photonics, Friedrich Schiller University Jena, Jena, Germany.|Institute of Photonic Technology, Jena, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Popp
authors.affiliation: Chair of Aquatic Geomicrobiology, Friedrich Schiller University Jena, Jena, Germany.|The German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany.
authors.forename: Kirsten
authors.initials: K
authors.lastname: Küsel
mesh_terms: D000143:Acids / Q000032:analysis*; D001105:Archaea / Q000145:classification* / Q000187:drug effects / Q000378:metabolism; D001419:Bacteria / Q000145:classification* / Q000187:drug effects / Q000378:metabolism; D016000:Cluster Analysis; D019641:DNA, Archaeal / Q000737:chemistry / Q000235:genetics; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D019015:Geologic Sediments / Q000737:chemistry* / Q000382:microbiology*; D007501:Iron / Q000378:metabolism; D064307:Microbiota / Q000187:drug effects*; D010084:Oxidation-Reduction; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D045483:Rivers; D017422:Sequence Analysis, DNA; D012965:Sodium Chloride / Q000032:analysis*; D014904:Western Australia
chemical_list: D000143:Acids; D019641:DNA, Archaeal; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D012965:Sodium Chloride; D007501:Iron