<abstract xmlns="http://www.w3.org/1999/xhtml">

<italic>Paramecium bursaria</italic> (Ciliophora) is a cosmopolitan unicellular organism that plays a significant role in aquatic ecosystems. <italic>P</italic>. <italic>bursaria</italic> contains symbiotic algae and this association is a mutual symbiosis. The aim of the present study was to determine the activity of photosystem II (PSII) in <italic>Chlorella</italic> sp. inside <italic>P</italic>. <italic>bursaria</italic> cells. Ciliates were incubated for 7 days at different temperatures from 6 to 18°C, under the circadian cycle: 12 h light/12 h dark, at light intensity of 200 μmol m-2 s-1 and under constant darkness conditions. The control group was kept at a temperature of 18°C under constant light conditions. Changes in PSII were monitored using different fluorescence parameters. Differences in responses between endosymbiotic algae of two <italic>P</italic>. <italic>bursaria</italic> strains – Ard7 from a warm climate and KD64 from a cold climate – were determined. The highest photosynthetic activity of <italic>P</italic>. <italic>bursaria</italic> green endosymbionts was observed at a temperature of 18°C, regardless of the light conditions. Algae from warm climate were more sensitive to cold temperature stress than algae from <italic>P</italic>. <italic>bursaria</italic> collected in cold climate.</abstract>

Paramecium bursaria (Ciliophora) is a cosmopolitan unicellular organism that plays a significant role in aquatic ecosystems. P. bursaria contains symbiotic algae and this association is a mutual symbiosis. The aim of the present study was to determine the activity of photosystem II (PSII) in Chlorella sp. inside P. bursaria cells. Ciliates were incubated for 7 days at different temperatures from 6 to 18°C, under the circadian cycle: 12 h light/12 h dark, at light intensity of 200 μmol m-2 s-1 and under constant darkness conditions. The control group was kept at a temperature of 18°C under constant light conditions. Changes in PSII were monitored using different fluorescence parameters. Differences in responses between endosymbiotic algae of two P. bursaria strains – Ard7 from a warm climate and KD64 from a cold climate – were determined. The highest photosynthetic activity of P. bursaria green endosymbionts was observed at a temperature of 18°C, regardless of the light conditions. Algae from warm climate were more sensitive to cold temperature stress than algae from P. bursaria collected in cold climate.

Photosynthetic efficiency of endosymbiotic algae of <italic>Paramecium bursaria</italic> originating from locations with cold and warm climates

Department of Marine Ecosystem Functioning

Oceanological and Hydrobiological Studies

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Photosynthetic efficiency of endosymbiotic algae of  originating from locations with cold and warm climates

Paramecium bursaria (Ciliophora) is a cosmopolitan unicellular organism that plays a significant role in aquatic ecosystems. P. bursaria contains symbiotic...

Photosynthetic efficiency of endosymbiotic algae of Paramecium bursaria originating from locations with cold and warm climates

Article Category: Short communication

Published Online: Jun 18, 2018

Page range: 202 - 210

Received: Sep 07, 2017

Accepted: Nov 21, 2017

DOI: https://doi.org/10.1515/ohs-2018-0019

© 2018 Faculty of Oceanography and Geography, University of Gdańsk, Poland

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.