Microbial growth under humic-free conditions in a supraglacial stream system on the Cotton Glacier, Antarctica
| Autor: | John T. Lisle, Heidi J. Smith, Diane M. McKnight, Michael D. SanClements, Yu-Ping Chin, Christine M. Foreman, Cindy E. Morris, Penney L. Miller, Rose M. Cory |
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| Přispěvatelé: | Montana State University (MSU), Earth & Environmental Sciences, Unité de Pathologie Végétale (PV), Institut National de la Recherche Agronomique (INRA), University of Colorado [Boulder], St Petersburg Coastal Marine Science Center, Partenaires INRAE, Rose-Hulman Institute of Technology, Ohio State University [Columbus] (OSU), NSF: OPP-0338260, OPP-0338299, OPP-0338121, OPP-0338342, Montana Space Grant Consortium, McKnight, Diane M. |
| Jazyk: | angličtina |
| Rok vydání: | 2013 |
| Předmět: |
010504 meteorology & atmospheric sciences
Biodiversité et Ecologie nucléation Bacterial growth 01 natural sciences activité de nucléation de la glace antarctique matière organique dissoute Dissolved organic carbon ultraviolet dissolved organic matter (DOM) extracellular emission matrices (EEMs) ice nucleation activity fluorescence glace Milieux et Changements globaux General Environmental Science 0303 health sciences geography.geographical_feature_category communauté microbienne biology Phototroph Ecology Aquatic ecosystem climat humide zone froide teneur en chlorophylle Environmental chemistry substance humique Proteobacteria cellule bactérienne fluorophore croissance microbienne [SDE.MCG]Environmental Sciences/Global Changes matrice extracellulaire Biodiversity and Ecology 03 medical and health sciences activité glaçogène 0105 earth and related environmental sciences geography ice nucleation activity (INA) système cryogénique 030306 microbiology Renewable Energy Sustainability and the Environment Public Health Environmental and Occupational Health adaptation au stress bacteroidetes Bacteroidetes Glacier biology.organism_classification matrice d'excitation-émission (MEE) écosystème aquatique Microbial population biology [SDE.BE]Environmental Sciences/Biodiversity and Ecology proteobacteria |
| Zdroj: | Environmental Research Letters Environmental Research Letters, IOP Publishing, 2013, 8 (3), ⟨10.1088/1748-9326/8/3/035022⟩ Environmental Research Letters 3 (8), . (2013) |
| ISSN: | 1748-9326 |
| DOI: | 10.1088/1748-9326/8/3/035022⟩ |
| Popis: | International audience; During the austral summers of 2004 and 2009, we sampled a supraglacial stream on the Cotton Glacier, Antarctica. The stream dissolved organic matter (DOM) was low (44-48 mu M C) and lacked detectable humic fluorescence signatures. Analysis of the excitation emissions matrices (EEMs) indicated that amino-acid fluorophores dominated, consistent with DOM of microbial origin, with little humic-like fluorescence. In most aquatic ecosystems, humic DOM attenuates harmful UV radiation and its absence may represent an additional stressor influencing the microbial community. Nonetheless, the stream contained an active microbial assemblage with bacterial cell abundances from 2.94 x 10(4) to 4.97 x 10(5) cells ml(-1), and bacterial production ranging from 58.8 to 293.2 ng C l(-1) d(-1). Chlorophyll-a concentrations ranged from 0.3 to 0.53 mu g l(-1) indicating that algal phototrophs were the probable source of the DOM. Microbial isolates produced a rainbow of pigment colors, suggesting adaptation to stress, and were similar to those from other cryogenic systems (Proteobacteria and Bacteroidetes lineages). Supraglacial streams provide an example of contemporary microbial processes on the glacier surface and a natural laboratory for studying microbial adaptation to the absence of humics. |
| Databáze: | OpenAIRE |
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