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1. Interannual variation in land-use intensity enhances grassland multidiversity

Author

Allan, Eric, Bossdorf, Oliver, Dormann, Carsten F., Prati, Daniel, Gossner, Martin M., Tscharntke, Teja, Blüthgen, Nico, Bellach, Michaela, Birkhofer, Klaus, Boch, Steffen, Böhm, Stefan, Börschig, Carmen, Chatzinotas, Antonis, Christ, Sabina, Daniel, Rolf, Diekötter, Tim, Fischer, Christiane, Friedl, Thomas, Glaser, Karin, Hallmann, Christine, Hodac, Ladislav, Hölzel, Norbert, Jung, Kirsten, Klein, Alexandra Maria, Klaus, Valentin H., Kleinebecker, Till, Krauss, Jochen, Lange, Markus, Morris, E. Kathryn, Müller, Jörg, Nacke, Heiko, Pašalić, Esther, Rillig, Matthias C., Rothenwöhrer, Christoph, Schally, Peter, Scherber, Christoph, Schulze, Waltraud, Socher, Stephanie A., Steckel, Juliane, Steffan-Dewenter, Ingolf, Türke, Manfred, Weiner, Christiane N., Werner, Michael, Westphal, Catrin, Wolters, Volkmar, Wubet, Tesfaye, Gockel, Sonja, Gorke, Martin, Hemp, Andreas, Renner, Swen C., Schöningt, Ingo, Pfeiffer, Simone, König-Ries, Birgitta, Buscot, François, Linsenmair, Karl Eduard, Schulzet, Ernst-Detlef, Weisser, Wolfgang W., and Fischer, Markus

Published
2014

6. The influence of microbial mats on travertine precipitation in active hydrothermal systems (Central Italy).

Author

Della Porta, Giovanna, Hoppert, Michael, Hallmann, Christine, Schneider, Dominik, and Reitner, Joachim

Subjects
MICROBIAL mats, CALCITE, TRAVERTINE, CALCITE crystals, WATER temperature, MICROBIAL communities, SULFUR bacteria, FILAMENTOUS bacteria
Abstract

The study of hydrothermal travertines contributes to the understanding of the interaction between physico‐chemical processes and microbial mats in carbonate precipitation. Three active travertine sites were investigated in Central Italy to characterise the types of carbonate precipitates and the associated microbial mats at varying physico‐chemical parameters. Carbonate precipitated fabrics at the decimetre to millimetre‐scale and microbial mat composition vary with decreasing water temperature: (a) at relatively higher temperature (55–44°C) calcite and aragonite crystals precipitate on microbial mats of Chloroflexi and sulphur‐oxidizing microbes forming filamentous streamer fabrics with sparse cyanobacteria, (b) at intermediate temperature (44–40°C), rafts, coated gas bubbles and dendrites are associated with Spirulina cyanobacteria and other filamentous and rod‐shaped cyanobacteria, (c) low temperature (34–33°C) laminated crusts and oncoids forming in a terraced slope system are associated with diverse Oscillatoriales and Nostocales filamentous cyanobacteria, Spirulina and diatoms. At the microscale, carbonate precipitates are similar in the three sites consisting of prismatic calcite crystals organised in radial rosettes or fibrous aragonite spherulites (40–300 µm in diameter), overlying or embedded in Extracellular Polymeric Substances. Clotted peloidal micrite dominates at temperatures <40°C, also encrusting filamentous microbes. Carbonates are associated with gypsum crystals; extracellular polymeric substances are enriched in silicon, aluminium, magnesium, calcium, phosphorous and sulphur; authigenic aluminium‐silicates form aggregates on Extracellular Polymeric Substances. This study confirms that microbial communities in hydrothermal settings vary as a function of water temperature. Carbonate precipitates at the microscale are similar in the three settings, despite different microbial communities, suggesting that travertine precipitation, driven by carbon dioxide degassing, is influenced by biofilm extracellular polymeric substances acting as a substrate for crystal nucleation (Extracellular Polymeric Substances‐mediated mineralization) and affecting the resultant fabric types, independently from specific microbial community composition and metabolism. [ABSTRACT FROM AUTHOR]

Published
2022
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14. Interannual variation in land-use intensity enhances grassland multidiversity

Author

Allan, Eric, primary, Bossdorf, Oliver, additional, Dormann, Carsten F., additional, Prati, Daniel, additional, Gossner, Martin M., additional, Tscharntke, Teja, additional, Blüthgen, Nico, additional, Bellach, Michaela, additional, Birkhofer, Klaus, additional, Boch, Steffen, additional, Böhm, Stefan, additional, Börschig, Carmen, additional, Chatzinotas, Antonis, additional, Christ, Sabina, additional, Daniel, Rolf, additional, Diekötter, Tim, additional, Fischer, Christiane, additional, Friedl, Thomas, additional, Glaser, Karin, additional, Hallmann, Christine, additional, Hodac, Ladislav, additional, Hölzel, Norbert, additional, Jung, Kirsten, additional, Klein, Alexandra Maria, additional, Klaus, Valentin H., additional, Kleinebecker, Till, additional, Krauss, Jochen, additional, Lange, Markus, additional, Morris, E. Kathryn, additional, Müller, Jörg, additional, Nacke, Heiko, additional, Pašalić, Esther, additional, Rillig, Matthias C., additional, Rothenwöhrer, Christoph, additional, Schall, Peter, additional, Scherber, Christoph, additional, Schulze, Waltraud, additional, Socher, Stephanie A., additional, Steckel, Juliane, additional, Steffan-Dewenter, Ingolf, additional, Türke, Manfred, additional, Weiner, Christiane N., additional, Werner, Michael, additional, Westphal, Catrin, additional, Wolters, Volkmar, additional, Wubet, Tesfaye, additional, Gockel, Sonja, additional, Gorke, Martin, additional, Hemp, Andreas, additional, Renner, Swen C., additional, Schöning, Ingo, additional, Pfeiffer, Simone, additional, König-Ries, Birgitta, additional, Buscot, François, additional, Linsenmair, Karl Eduard, additional, Schulze, Ernst-Detlef, additional, Weisser, Wolfgang W., additional, and Fischer, Markus, additional

Published
2013
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18. Ascomycete fungi on dimension stone of the 'Burg Gleichen', Thuringia

Author

Hallmann, Christine, Fritzlar, Diana, Stannek, Lorena, and Hoppert, Michael

Subjects
15. Life on land
Abstract

In the present study, the diversity of ascomycete fungi was investigated on two wall areas of the “Burg Gleichen”, Thuringia (Germany), made of various types of sandstones, travertine and Grenzdolomit. From a W-exposed, shaded wall area, free-living ascomycetes (mainly “black fungi”) and green algae could be retrieved from sandstone lithologies. Sandstone from an ESE-exposed area was mainly colonized by lichen ascomycetes and the lichen alga Trebouxia. Both areas share a small number of generalist species, related to the ascomycete black fungi Sarcinomyces petricola, Phaeococcomyces chersonesos and Stichococcus mirabilis. Free-living black fungi were isolated and characterized with respect to cell wall morphology and melanin content. A remarkably rigid melanin layer, incorporated in the cell wall of a Cladosporium isolate is presented in detail.

19. Microbial diversity on a marble monument: a case study

Author

Hallmann, Christine, Rüdrich, Jörg, Enseleit, Matthias, Friedl, Thomas, and Hoppert, Michael

Subjects
15. Life on land
Abstract

In the presented case study, ascomycete fungi and green algae on a marble monument were identified by comparisons of the 18S rRNA gene sequences, which were obtained from DNA either from environmental samples or from enrichment cultures. The organisms were found to be responsible for either black or green surface coverings on different areas of the monument surface. Most fungi were related to plant-inhabiting genera, corresponding to a heavy soiling of the marble surface with honeydew. Whereas green algae of the genera Stichococcus, Chloroidium and Apatococcus were found to be dominant in all samples, isolates of two additional genera were recovered only from enrichment cultures. A reference strain of Apatococcus lobatus and an isolate of Prasiolopsis sp. were investigated with respect to putative surface adhesive structures of the cell envelope. The Prasiolopsis cell walls were covered with a thin adhesive exopolysaccharide layer involved in biofilm formation.

20. Widespread green algae Chlorella and Stichococcus exhibit polar-temperate and tropical-temperate biogeography.

Author

Hodač L, Hallmann C, Spitzer K, Elster J, Faßhauer F, Brinkmann N, Lepka D, Diwan V, and Friedl T

Subjects
Antarctic Regions, Arctic Regions, Biofilms classification, Chlorella vulgaris genetics, Chlorophyta genetics, DNA, Ribosomal Spacer genetics, Ecosystem, Phylogeny, Phylogeography, Chlorella vulgaris classification, Chlorella vulgaris growth & development, Chlorophyta classification, Chlorophyta growth & development, Cold Climate
Abstract

Chlorella and Stichococcus are morphologically simple airborne microalgae, omnipresent in terrestrial and aquatic habitats. The minute cell size and resistance against environmental stress facilitate their long-distance dispersal. However, the actual distribution of Chlorella- and Stichococcus-like species has so far been inferred only from ambiguous morphology-based evidence. Here we contribute a phylogenetic analysis of an expanded SSU and ITS2 rDNA sequence dataset representing Chlorella- and Stichococcus-like species from terrestrial habitats of polar, temperate and tropical regions. We aim to uncover biogeographical patterns at low taxonomic levels. We found that psychrotolerant strains of Chlorella and Stichococcus are closely related with strains originating from the temperate zone. Species closely related to Chlorella vulgaris and Muriella terrestris, and recovered from extreme terrestrial environments of polar regions and hot deserts, are particularly widespread. Stichococcus strains from the temperate zone, with their closest relatives in the tropics, differ from strains with the closest relatives being from the polar regions. Our data suggest that terrestrial Chlorella and Stichococcus might be capable of intercontinental dispersal; however, their actual distributions exhibit biogeographical patterns., (© FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Published
2016
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