title: Cyanobacterial Contribution to Travertine Deposition in the Hoyoux River System, Belgium.
abstract: Travertine deposition is a landscape-forming process, usually building a series of calcareous barriers differentiating the river flow into a series of cascades and ponds. The process of carbonate precipitation is a complex relationship between biogenic and abiotic causative agents, involving adapted microbial assemblages but also requiring high levels of carbonate saturation, spontaneous degassing of carbon dioxide and slightly alkaline pH. We have analysed calcareous crusts and water chemistry from four sampling sites along the Hoyoux River and its Triffoy tributary (Belgium) in winter, spring, summer and autumn 2014. Different surface textures of travertine deposits correlated with particular microenvironments and were influenced by the local water flow. In all microenvironments, we have identified the cyanobacterium Phormidium incrustatum (Nägeli) Gomont as the organism primarily responsible for carbonate precipitation and travertine fabric by combining morphological analysis with molecular sequencing (16S rRNA gene and ITS, the Internal Transcribed Spacer fragments), targeting both field populations and cultures to exclude opportunistic microorganisms responding favourably to culture conditions. Several closely related cyanobacterial strains were cultured; however, only one proved identical with the sequences obtained from the field population by direct PCR. This strain was the dominant primary producer in the calcareous deposits under study and in similar streams in Europe. The dominance of one organism that had a demonstrated association with carbonate precipitation presented a valuable opportunity to study its function in construction, preservation and fossilisation potential of ambient temperature travertine deposits. These relationships were examined using scanning electron microscopy and Raman microspectroscopy.
authors.affiliation: InBios Center for Protein Engineering, University of Liège, B-4000, Liège, Belgium. Julia.Kleinteich@gmail.com.|Center for Applied Geosciences, University of Tübingen, D-72074, Tübingen, Germany. Julia.Kleinteich@gmail.com.
authors.forename: Julia
authors.initials: J
authors.lastname: Kleinteich
authors.affiliation: InBios Center for Protein Engineering, University of Liège, B-4000, Liège, Belgium.|Biological Science Center, Boston University, Boston, MA, 02215, USA.|Palaeobiogeology, Palaeobotany, Palaeopalynology, Department of Geology, UR Geology B18, University of Liège, B-4000, Liège, Belgium.
authors.forename: Stjepko
authors.initials: S
authors.lastname: Golubic
authors.affiliation: InBios Center for Protein Engineering, University of Liège, B-4000, Liège, Belgium.
authors.forename: Igor S
authors.initials: IS
authors.lastname: Pessi
authors.affiliation: InBios Center for Protein Engineering, University of Liège, B-4000, Liège, Belgium.|Department of Biology, Universidad Autónoma de Madrid, E-28049, Madrid, Spain.
authors.forename: David
authors.initials: D
authors.lastname: Velázquez
authors.affiliation: Palaeobiogeology, Palaeobotany, Palaeopalynology, Department of Geology, UR Geology B18, University of Liège, B-4000, Liège, Belgium.
authors.forename: Jean-Yves
authors.initials: JY
authors.lastname: Storme
authors.affiliation: Chemical Oceanography Unit, Institut de Physique (B5), University of Liege, B-4000, Liège, Belgium.
authors.forename: François
authors.initials: F
authors.lastname: Darchambeau
authors.affiliation: Chemical Oceanography Unit, Institut de Physique (B5), University of Liege, B-4000, Liège, Belgium.
authors.forename: Alberto V
authors.initials: AV
authors.lastname: Borges
authors.affiliation: Department of Biology, Ecology and Evolution (BEE)/Centre of Aid for Research and Education in Microscopy (CAREM), University of Liège, B-4000, Liège, Belgium.
authors.forename: Philippe
authors.initials: P
authors.lastname: Compère
authors.affiliation: Hessisches Landesamt für Naturschutz, Umwelt und Geologie, Rheingaustr. 186, D-65203, Wiesbaden, Germany.
authors.forename: Gudrun
authors.initials: G
authors.lastname: Radtke
authors.affiliation: Department of Geology, Kyungpook National University, 1370 Sankyuck-dong, Daegu, 702-701, South Korea.
authors.forename: Seong-Joo
authors.initials: SJ
authors.lastname: Lee
authors.affiliation: Palaeobiogeology, Palaeobotany, Palaeopalynology, Department of Geology, UR Geology B18, University of Liège, B-4000, Liège, Belgium.
authors.forename: Emmanuelle J
authors.initials: EJ
authors.lastname: Javaux
authors.affiliation: InBios Center for Protein Engineering, University of Liège, B-4000, Liège, Belgium.
authors.forename: Annick
authors.initials: A
authors.lastname: Wilmotte
mesh_terms: D001530:Belgium; D002254:Carbonates / Q000032:analysis*; D000458:Cyanobacteria / Q000235:genetics / Q000378:metabolism*; D021903:DNA, Ribosomal Spacer / Q000235:genetics; D005060:Europe; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D045483:Rivers
chemical_list: D002254:Carbonates; D021903:DNA, Ribosomal Spacer; D012336:RNA, Ribosomal, 16S
keywords: Calcareous tufa; Culture support; Cyanobacteria; Travertine deposition; rRNA operon sequencing