Predominance of b-proteobacteria in summer melt pools on Arctic pack ice
The diversity and community structure of bacteria in melt pools on Arctic pack ice floes were dominated by b-proteobacteria. Thirty-five percent of the pure cultures isolated in 1997 from pack ice floes north of Svalbard and in the Fram Strait were from the b-proteobacteria group. Within this group,...
| Main Authors: | , , |
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| Format: | Text |
| Language: | English |
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.533.6651 http://www.aslo.org/lo/toc/vol_49/issue_4/1013.pdf |
| Summary: | The diversity and community structure of bacteria in melt pools on Arctic pack ice floes were dominated by b-proteobacteria. Thirty-five percent of the pure cultures isolated in 1997 from pack ice floes north of Svalbard and in the Fram Strait were from the b-proteobacteria group. Within this group, there were only two phylotypes clus-tering within the widespread Beta I cluster, also known as the Comamonadaceae clade. One phylotype, most closely related to Aquaspirillum arcticum (96.0–97.3 % identical), was frequent among cultures isolated from 10 melt pools. A 16S ribosomal RNA (rRNA) gene clone library, constructed from a melt pool that was sampled 2 yr later in the Fram Strait, was also dominated by b-proteobacteria, in particular the same recurrent isolate phylotype designated ‘‘MP-BetaI’’. Fluorescence in situ hybridization of 20 melt pools corroborated the cultivation and cloning data. b-Proteobacteria were the most abundant bacterial group, constituting;49 % of the bacteria that were stained by 496-diamidino-2-phenylindole (DAPI). a- and g-proteobacteria accounted for only 2 % each, the Cytophaga–Flavobac-terium group accounted for 9%, and the Actinobacteria spp. accounted for 9%. Approximately 63 % of the b-proteobacterial fraction that was found in the melt pools was determined with a newly developed probe to be the recurrent b-proteobacterial MP-BetaI phylotypes, indicating that it is particularly adapted for success in this extreme environment. |
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