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Exopolymer particles: microbial hotspots of enhanced bacterial activity in Arctic fast ice (Chukchi Sea)
Citation
Meiners, K and Krembs, C and Gradinger, R, Exopolymer particles: microbial hotspots of enhanced bacterial activity in Arctic fast ice (Chukchi Sea), Aquatic Microbial Ecology, 52, (2) pp. 195-207. ISSN 0948-3055 (2008) [Refereed Article]
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Copyright Statement
Copyright © 2008 Inter-Research
Official URL: http://www.int-res.com/
DOI: doi:10.3354/ame01214
Abstract
Sea ice is an important structuring element of Arctic marine ecosystems and provides a
vast low-temperature habitat for ice-associated bacteria. While it is now known that sea ice
sequesters large amounts of extracellular polymeric substances (EPS) contributing significantly to its
particulate organic carbon pool, the ecological role of EPS in sea ice is poorly understood. Using in
situ incubations combined with a newly developed triple-staining method (Alcian Blue, DAPI, CTC),
we determined the number of CTC-reducing (i.e. actively respiring) sea-ice bacteria living freely or
attached to gel-like exopolymer particles. Samples were collected at 6 depths from Chukchi Sea
coastal fast ice in April, May and June 2003. Concentrations of exopolymer particles ranged between
1.8 × 106 and 149.1 × 106 particles l–1 (average 4.7 × 106 particles l–1) and showed strong vertical gradients
with maximum concentrations at the ice-water interface. Total bacterial numbers (TBN)
ranged from 0.18 × 109 to 8.48 × 109 cells l–1 with an average fraction of 7.4% of actively respiring cells
(range 3.0 to 17.2% of TBN). The attached bacterial fraction (range 4.6 to 28.5%, average 15.0% of
TBN) showed a significantly, approximately 4 times higher proportion of actively respiring cells
(average 19.6%, range 7.8 to 37.6%) when compared to the free-living fraction that had an average
of 5.4% (range 1.1 to 11.2%) of actively respiring cells. In conclusion, exopolymer particles in sea ice
are microbial hotspots of increased bacterial activity able to foster enhanced biogeochemical cycling.
Item Details
Item Type: | Refereed Article |
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Keywords: | Sea ice · Arctic · Exopolymer particles · Extracellular polymeric substances · Particle colonisation · Bacterial activity · CTC |
Research Division: | Biological Sciences |
Research Group: | Microbiology |
Research Field: | Bacteriology |
Objective Division: | Environmental Management |
Objective Group: | Management of Antarctic and Southern Ocean environments |
Objective Field: | Biodiversity in Antarctic and Southern Ocean environments |
UTAS Author: | Meiners, K (Dr Klaus Meiners) |
ID Code: | 54795 |
Year Published: | 2008 |
Web of Science® Times Cited: | 43 |
Deposited By: | CRC-Antarctic Climate & Ecosystems |
Deposited On: | 2009-02-27 |
Last Modified: | 2009-06-09 |
Downloads: | 1 View Download Statistics |
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