title: Cinderella's helping pigeons of the microbial world: The potential of testate amoebae for identifying cryptotephra.
abstract: Cryptotephra (particles <125μm) is a key record for monitoring past and current volcanic activity. However, its extraction from the host sediment and analysis is often long and difficult because of its small size. Finding a simple method to extract cryptotephra from environmental samples would therefore make its analysis much easier. We hypothesized that arcellinid testate amoebae may hold such a potential. These free-living shelled protists are among the earliest microorganisms to colonize volcanic tephra, and build their shell by agglutinating minerals from their environment. We analyzed by X-ray Spectrometry the mineral signature of tephra from the 2011 Puyehue-Cordon Caulle Volcanic Complex (Chile) eruption ash fallout and compared it to that of the shells of 51 individual testate amoebae (three individuals from each of 17 species) from 13 samples collected at different distances from the active vent. The mineral composition of particles within shells closely matched that of similar size class particles from their environment. The capacity of testate amoebae to randomly use mineral grains from their environment makes it possible to use their shells to assess the mineral composition of cryptotephra from soil, peat or sediment samples. Testate amoebae therefore represent the microbial world's version of Cinderella's helping pigeons.
authors.affiliation: Laboratoire Chrono-Environnement, UMR 6249, Université de Bourgogne Franche-Comté, 16 route de Gray, 25030 Besançon Cedex, France; Université de Lille, UMR LOG 8187 CNRS, ULCO, Laboratoire d'Océanologie et Géosciences, Bâtiment SN5, 59655 Villeneuve-d'Ascq, France. Electronic address: maxence.delaine@gmx.fr.
authors.forename: Maxence
authors.initials: M
authors.lastname: Delaine
authors.affiliation: Laboratory of Soil Biodiversity, Institute of Biology, University of Neuchâtel, Rue Emile Argand 11, CH-2000 Neuchâtel, Switzerland; Laboratorio de Ecología Evolutiva y Filoinformática, Departamento de Zoología, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Barrio Universitario s/n, Casilla 160-C, Concepción, Chile. Electronic address: limnoleo@gmail.com.
authors.forename: Leonardo D
authors.initials: LD
authors.lastname: Fernández
authors.affiliation: Université de Lille, UMR LOG 8187 CNRS, ULCO, Laboratoire d'Océanologie et Géosciences, Bâtiment SN5, 59655 Villeneuve-d'Ascq, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Armynot du Châtelet
authors.affiliation: Université de Lille, UMR LOG 8187 CNRS, ULCO, Laboratoire d'Océanologie et Géosciences, Bâtiment SN5, 59655 Villeneuve-d'Ascq, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Recourt
authors.affiliation: Université de Lille, UMR LOG 8187 CNRS, ULCO, Laboratoire d'Océanologie et Géosciences, Bâtiment SN5, 59655 Villeneuve-d'Ascq, France.
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Potdevin
authors.affiliation: Laboratory of Soil Biodiversity, Institute of Biology, University of Neuchâtel, Rue Emile Argand 11, CH-2000 Neuchâtel, Switzerland; Botanical Garden of Neuchâtel, Chemin du Perthuis-du-Sault 58, CH-2000 Neuchâtel, Switzerland.
authors.forename: Edward A D
authors.initials: EA
authors.lastname: Mitchell
authors.affiliation: Laboratoire Chrono-Environnement, UMR 6249, Université de Bourgogne Franche-Comté, 16 route de Gray, 25030 Besançon Cedex, France; Laboratoire THéMA, UMR 6049, CNRS, Université de Bourgogne Franche-Comté, 32 rue Mégevand, 25030 Besançon Cedex, France.
authors.forename: Nadine
authors.initials: N
authors.lastname: Bernard
mesh_terms: D000656:Amoeba / Q000737:chemistry*; D002677:Chile; D005844:Geology / Q000379:methods*; D008903:Minerals / Q000032:analysis*; D015999:Multivariate Analysis; D018707:Volcanic Eruptions / Q000032:analysis*
chemical_list: D008903:Minerals
keywords: Arcellinida; Cryptotephra; Elemental analyzes; Free-living unicellular eukaryotes; Puyehue-Cordon Caulle volcanic complex; Shell composition