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Extremophile microbiomes in acidic and hypersaline river sediments of W estern A ustralia
Author(s) -
Lu Shipeng,
Peiffer Stefan,
Lazar Cassandre Sara,
Oldham Carolyn,
Neu Thomas R.,
Ciobota Valerian,
Näb Olga,
Lillicrap Adam,
Rösch Petra,
Popp Jürgen,
Küsel Kirsten
Publication year - 2016
Publication title -
environmental microbiology reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.229
H-Index - 69
ISSN - 1758-2229
DOI - 10.1111/1758-2229.12351
Subject(s) - extremophile , extreme environment , microbial population biology , anoxic waters , sediment , environmental chemistry , schwertmannite , jarosite , sulfate , chemistry , halophile , biology , microorganism , bacteria , mineralogy , paleontology , genetics , organic chemistry , adsorption , goethite
Summary 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 W estern A ustralia. In W est D alyup R iver, large amounts of NaC l, F e( 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 F e( II ) oxidation because chemical oxidation is greatly reduced at low pH . 16S r RNA gene diversity analyses revealed that sequences affiliated with an uncultured archaeal lineage named A plasma, which has the genomic potential for F e( II ) oxidation, were dominant in both sediment samples. The acidophilic heterotrophs A cidiphilium and A cidocella were identified as the dominant bacterial groups. A cidiphilium strain AusYE 3‐1 obtained from the river sediment tolerated up to 6% NaC l at pH 3 under oxic conditions and cells of strain AusYE 3‐1 reduced the effects of high salt content by forming filamentous structure clumping as aggregates. Neither growth nor F e( III ) reduction by strain AusYE 3‐1 was observed in anoxic salt‐containing medium. The detection of A plasma group as potential F e( II ) oxidizers and the inhibited F e( III )‐reducing capacity of A cidiphilium contributes to our understanding of the microbial ecology of acidic hypersaline environments.