The ice nucleation activity of green algae isolated from low-temperature environments
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| Rok publikování | 2010 |
| Druh | Konferenční abstrakty |
| Fakulta / Pracoviště MU | |
| Citace | |
| Popis | Abstract: The survival of the algae at low temperatures requires many adaptation/acclimatization strategies. The algae from different cold habitats could develop various mechanisms of freezing tolerance and cryoprotective mechanisms. In our study, two groups of algae living in different low-temperature environments were evaluated. The environment of snow algae - melting snow - is characterised by stable temperatures around 0 deg C and water is usually available. On the other hand, the lichen thalli are subjected to temperature and moisture variation and undergo dehydration-hydration cycles. Ice nucleation activities of two species of snow algae, Chlamydomonas nivalis and Chloromonas nivalis, three lichen fycobiont algae, Trebouxia asymmetrica, Trebouxia erici and Trebouxia glomerata, and one mesophilic alga Chlamydomonas reinhardtii (control) were studied by ice nucleation spectroscopy. Freezing points of 25 droplets of algal suspension and 5 control droplets of DNA-se free water were recorded. The volume of a droplet was 2 micro l. The droplets were pipetted on an aluminium foil stuck to an aluminium plate that had been cooled at rate of 1 deg C/min, and the temperature of the plate was measured. For each droplet, the freezing temperature was recorded by a digital camera (Fig. 1) The freezing temperatures of the snow algae were higher than those of the lichen fycobionts reflecting stable conditions of their environment. Since the algae are bad ice nucleators, with exception of the Chloromonas nivalis, where fungal contamination can not been excluded, other cryoprotective mechanisms must be considered. Acknowledgements: GAAV KJB601630808, GAAV KJB600050708, CAREX Knowledge Grants and institutional long-term research plan of the Institute of Botany AS CR AV0Z60050516. Theme 2: Past, present and future changes in Polar Regions. Session: T2-3 Snow and ice dynamics and processes. Time: Sometime between Friday 11 June 16:00 and 17:30 h. |
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