High-resolution ice nucleation spectra of sea-ice bacteria: implications for cloud formation and life in frozen environments
Even though studies of Arctic ice forming particles suggest that a bacterial or viral source derived from open leads could be important for ice formation in Arctic clouds (Bigg and Leck, 2001), the ice nucleation potential of most polar marine psychrophiles or viruses has not been examined under con...
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ftdoajarticles:oai:doaj.org/article:9692dc04f9b5474291bb8deaed5e8431 2023-05-15T13:43:23+02:00 High-resolution ice nucleation spectra of sea-ice bacteria: implications for cloud formation and life in frozen environments K. Junge B. D. Swanson 2008-05-01T00:00:00Z https://doaj.org/article/9692dc04f9b5474291bb8deaed5e8431 EN eng Copernicus Publications http://www.biogeosciences.net/5/865/2008/bg-5-865-2008.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 1726-4170 1726-4189 https://doaj.org/article/9692dc04f9b5474291bb8deaed5e8431 Biogeosciences, Vol 5, Iss 3, Pp 865-873 (2008) Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 article 2008 ftdoajarticles 2022-12-31T08:11:43Z Even though studies of Arctic ice forming particles suggest that a bacterial or viral source derived from open leads could be important for ice formation in Arctic clouds (Bigg and Leck, 2001), the ice nucleation potential of most polar marine psychrophiles or viruses has not been examined under conditions more closely resembling those in the atmosphere. In this paper, we examined the ice nucleation activity (INA) of several representative Arctic and Antarctic sea-ice bacterial isolates and a polar Colwellia phage virus. High-resolution ice nucleation spectra were obtained for droplets containing bacterial cells or virus particles using a free-fall freezing tube technique. The fraction of frozen droplets at a particular droplet temperature was determined by measuring the depolarized light scattering intensity from solution droplets in free-fall. Our experiments revealed that all sea-ice isolates and the virus nucleated ice at temperatures very close to the homogeneous nucleation temperature for the nucleation medium – which for artificial seawater was –42.2±0.3°C. Our results suggest that immersion freezing of these marine psychro-active bacteria and viruses would not be important for heterogeneous ice nucleation processes in polar clouds or to the formation of sea ice. These results also suggested that avoidance of ice formation in close proximity to cell surfaces might be one of the cold-adaptation and survival strategies for sea-ice bacteria. The fact that INA occurs at such low temperature could constitute one factor that explains the persistence of metabolic activities at temperatures far below the freezing point of seawater. Article in Journal/Newspaper Antarc* Antarctic Arctic Sea ice Directory of Open Access Journals: DOAJ Articles Antarctic Arctic |
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Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 |
spellingShingle |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 K. Junge B. D. Swanson High-resolution ice nucleation spectra of sea-ice bacteria: implications for cloud formation and life in frozen environments |
topic_facet |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 |
description |
Even though studies of Arctic ice forming particles suggest that a bacterial or viral source derived from open leads could be important for ice formation in Arctic clouds (Bigg and Leck, 2001), the ice nucleation potential of most polar marine psychrophiles or viruses has not been examined under conditions more closely resembling those in the atmosphere. In this paper, we examined the ice nucleation activity (INA) of several representative Arctic and Antarctic sea-ice bacterial isolates and a polar Colwellia phage virus. High-resolution ice nucleation spectra were obtained for droplets containing bacterial cells or virus particles using a free-fall freezing tube technique. The fraction of frozen droplets at a particular droplet temperature was determined by measuring the depolarized light scattering intensity from solution droplets in free-fall. Our experiments revealed that all sea-ice isolates and the virus nucleated ice at temperatures very close to the homogeneous nucleation temperature for the nucleation medium – which for artificial seawater was –42.2±0.3°C. Our results suggest that immersion freezing of these marine psychro-active bacteria and viruses would not be important for heterogeneous ice nucleation processes in polar clouds or to the formation of sea ice. These results also suggested that avoidance of ice formation in close proximity to cell surfaces might be one of the cold-adaptation and survival strategies for sea-ice bacteria. The fact that INA occurs at such low temperature could constitute one factor that explains the persistence of metabolic activities at temperatures far below the freezing point of seawater. |
format |
Article in Journal/Newspaper |
author |
K. Junge B. D. Swanson |
author_facet |
K. Junge B. D. Swanson |
author_sort |
K. Junge |
title |
High-resolution ice nucleation spectra of sea-ice bacteria: implications for cloud formation and life in frozen environments |
title_short |
High-resolution ice nucleation spectra of sea-ice bacteria: implications for cloud formation and life in frozen environments |
title_full |
High-resolution ice nucleation spectra of sea-ice bacteria: implications for cloud formation and life in frozen environments |
title_fullStr |
High-resolution ice nucleation spectra of sea-ice bacteria: implications for cloud formation and life in frozen environments |
title_full_unstemmed |
High-resolution ice nucleation spectra of sea-ice bacteria: implications for cloud formation and life in frozen environments |
title_sort |
high-resolution ice nucleation spectra of sea-ice bacteria: implications for cloud formation and life in frozen environments |
publisher |
Copernicus Publications |
publishDate |
2008 |
url |
https://doaj.org/article/9692dc04f9b5474291bb8deaed5e8431 |
geographic |
Antarctic Arctic |
geographic_facet |
Antarctic Arctic |
genre |
Antarc* Antarctic Arctic Sea ice |
genre_facet |
Antarc* Antarctic Arctic Sea ice |
op_source |
Biogeosciences, Vol 5, Iss 3, Pp 865-873 (2008) |
op_relation |
http://www.biogeosciences.net/5/865/2008/bg-5-865-2008.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 1726-4170 1726-4189 https://doaj.org/article/9692dc04f9b5474291bb8deaed5e8431 |
_version_ |
1766188177736859648 |