Effects of Temperature on Two Psychrophilic Ecotypes of a Heterotrophic Nanoflagellate, Paraphysomonas imperforata
Two different psychrophilic types of the heterotrophic nanoflagellate Paraphysomonas imperforata were isolated from Newfoundland coastal waters and the Arctic Ocean. When fed bacteria without food limitation, both isolates were able to grow at temperatures from -1.8 to 20°C, with maximum growth rate...
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ftpubmed:oai:pubmedcentral.nih.gov:195289 2023-05-15T14:48:20+02:00 Effects of Temperature on Two Psychrophilic Ecotypes of a Heterotrophic Nanoflagellate, Paraphysomonas imperforata Choi, Joon W. Peters, Francesc 1992-02 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC195289 http://www.ncbi.nlm.nih.gov/pubmed/16348647 en eng http://www.ncbi.nlm.nih.gov/pmc/articles/PMC195289 http://www.ncbi.nlm.nih.gov/pubmed/16348647 Copyright © 1992, American Society for Microbiology General Microbial Ecology Text 1992 ftpubmed 2013-08-29T13:54:54Z Two different psychrophilic types of the heterotrophic nanoflagellate Paraphysomonas imperforata were isolated from Newfoundland coastal waters and the Arctic Ocean. When fed bacteria without food limitation, both isolates were able to grow at temperatures from -1.8 to 20°C, with maximum growth rates of 3.28 day-1 at 15°C and 2.28 day-1 at 12.3°C for the Newfoundland and the Arctic isolates, respectively. Ingestion rates increased with temperature from 14 to 62 bacteria flagellate-1 h-1 for the Newfoundland isolate and from 30 to 99 bacteria flagellate-1 h-1 for the Arctic isolate. While temperature did not affect cell yields (number of protozoa produced divided by number of bacteria consumed), it affected flagellate sizes. This differential effect of temperature on cell yield and cell size resulted in a changing gross growth efficiency (GGE) in terms of biovolume; colder temperatures favored higher GGEs. The comparison of Q10 values for growth rates and ingestion rates between the isolates shows that the Arctic isolate is better adapted to extremely cold temperature than the Newfoundland isolate. At seawater-freezing temperature (-1.8°C), the estimated maximum growth rates and maximum ingestion rates are 0.81 day-1 and 30 bacteria flagellate-1 h-1 for the Arctic isolate and 0.54 day-1 and 12 bacteria flagellate-1 h-1 for the Newfoundland isolate. Our findings about psychrophilic nanoflagellates fit the general characteristics of cold-water-dwelling organisms: reduced physiological rates and higher GGEs at lower temperatures. Because of the large and persistent differences between the isolates, we conclude that they are ecotypes adapted to specific environmental conditions. Text Arctic Arctic Ocean Newfoundland PubMed Central (PMC) Arctic Arctic Ocean |
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General Microbial Ecology |
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General Microbial Ecology Choi, Joon W. Peters, Francesc Effects of Temperature on Two Psychrophilic Ecotypes of a Heterotrophic Nanoflagellate, Paraphysomonas imperforata |
topic_facet |
General Microbial Ecology |
description |
Two different psychrophilic types of the heterotrophic nanoflagellate Paraphysomonas imperforata were isolated from Newfoundland coastal waters and the Arctic Ocean. When fed bacteria without food limitation, both isolates were able to grow at temperatures from -1.8 to 20°C, with maximum growth rates of 3.28 day-1 at 15°C and 2.28 day-1 at 12.3°C for the Newfoundland and the Arctic isolates, respectively. Ingestion rates increased with temperature from 14 to 62 bacteria flagellate-1 h-1 for the Newfoundland isolate and from 30 to 99 bacteria flagellate-1 h-1 for the Arctic isolate. While temperature did not affect cell yields (number of protozoa produced divided by number of bacteria consumed), it affected flagellate sizes. This differential effect of temperature on cell yield and cell size resulted in a changing gross growth efficiency (GGE) in terms of biovolume; colder temperatures favored higher GGEs. The comparison of Q10 values for growth rates and ingestion rates between the isolates shows that the Arctic isolate is better adapted to extremely cold temperature than the Newfoundland isolate. At seawater-freezing temperature (-1.8°C), the estimated maximum growth rates and maximum ingestion rates are 0.81 day-1 and 30 bacteria flagellate-1 h-1 for the Arctic isolate and 0.54 day-1 and 12 bacteria flagellate-1 h-1 for the Newfoundland isolate. Our findings about psychrophilic nanoflagellates fit the general characteristics of cold-water-dwelling organisms: reduced physiological rates and higher GGEs at lower temperatures. Because of the large and persistent differences between the isolates, we conclude that they are ecotypes adapted to specific environmental conditions. |
format |
Text |
author |
Choi, Joon W. Peters, Francesc |
author_facet |
Choi, Joon W. Peters, Francesc |
author_sort |
Choi, Joon W. |
title |
Effects of Temperature on Two Psychrophilic Ecotypes of a Heterotrophic Nanoflagellate, Paraphysomonas imperforata |
title_short |
Effects of Temperature on Two Psychrophilic Ecotypes of a Heterotrophic Nanoflagellate, Paraphysomonas imperforata |
title_full |
Effects of Temperature on Two Psychrophilic Ecotypes of a Heterotrophic Nanoflagellate, Paraphysomonas imperforata |
title_fullStr |
Effects of Temperature on Two Psychrophilic Ecotypes of a Heterotrophic Nanoflagellate, Paraphysomonas imperforata |
title_full_unstemmed |
Effects of Temperature on Two Psychrophilic Ecotypes of a Heterotrophic Nanoflagellate, Paraphysomonas imperforata |
title_sort |
effects of temperature on two psychrophilic ecotypes of a heterotrophic nanoflagellate, paraphysomonas imperforata |
publishDate |
1992 |
url |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC195289 http://www.ncbi.nlm.nih.gov/pubmed/16348647 |
geographic |
Arctic Arctic Ocean |
geographic_facet |
Arctic Arctic Ocean |
genre |
Arctic Arctic Ocean Newfoundland |
genre_facet |
Arctic Arctic Ocean Newfoundland |
op_relation |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC195289 http://www.ncbi.nlm.nih.gov/pubmed/16348647 |
op_rights |
Copyright © 1992, American Society for Microbiology |
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1766319426055962624 |