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| Titel |
Microbial colonization in diverse surface soil types in Surtsey and diversity analysis of its subsurface microbiota |
| VerfasserIn |
V. Marteinsson, A. Klonowski, E. Reynisson, P. Vannier, B. D. Sigurdsson, M. Ólafsson |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1726-4170
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| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 12, no. 4 ; Nr. 12, no. 4 (2015-02-24), S.1191-1203 |
| Datensatznummer |
250117830
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| Publikation (Nr.) |
 copernicus.org/bg-12-1191-2015.pdf |
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| Zusammenfassung |
| Colonization of life on Surtsey has been observed systematically since the
formation of the island 50 years ago. Although the first colonisers were
prokaryotes, such as bacteria and blue–green algae, most studies have been
focused on the settlement of plants and animals but less on microbial
succession. To explore microbial colonization in diverse soils and the
influence of associated vegetation and birds on numbers of environmental
bacteria, we collected 45 samples from different soil types on the surface
of the island. Total viable bacterial counts were performed with the plate
count method
at 22, 30 and 37 °C for all soil samples,
and the amount of organic matter and nitrogen (N) was measured. Selected
samples were also tested for coliforms, faecal coliforms and aerobic and
anaerobic bacteria. The subsurface biosphere was investigated by collecting
liquid subsurface samples from a 181 m borehole with a special sampler.
Diversity analysis of uncultivated biota in samples was performed by 16S
rRNA gene sequences analysis and cultivation. Correlation was observed
between nutrient deficits and the number of microorganisms in surface soil
samples. The lowest number of bacteria (1 × 104–1 × 105 cells g−1) was
detected in almost pure pumice but the count was significantly higher
(1 × 106–1 × 109 cells g−1) in vegetated soil or pumice with bird droppings.
The number of faecal bacteria correlated also to the total number of
bacteria and type of soil. Bacteria belonging to Enterobacteriaceae were only detected in
vegetated samples and samples containing bird droppings. The human pathogens
Salmonella, Campylobacter and Listeria were not in any sample. Both thermophilic bacteria and archaea 16S
rDNA sequences were found in the subsurface samples collected at 145 and
172 m depth at 80 and 54 °C, respectively, but no
growth was observed in enrichments. The microbiota sequences generally
showed low affiliation to any known 16S rRNA gene sequences. |
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