Phagotrophy in Photosynthetic Eukaryotic Microbes from Polar Environments
Biology Ph.D. Polar regions impose harsh conditions, including low temperatures, and prolonged periods of darkness on resident microbial communities. Despite these challenges, the conditions in these environments can also create opportunities for organisms utilizing combined trophic strategies (Mixo...
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fttempleunivdc:oai:cdm16002.contentdm.oclc.org:p245801coll10/305304 2024-02-11T09:56:11+01:00 Phagotrophy in Photosynthetic Eukaryotic Microbes from Polar Environments McKie-Krisberg, Zaid Mahira Sanders, Robert W.; Cordes, Erik E.; Nicholson, Allen W.; Gast, Rebecca J.; 2014 Application/PDF 107 6817083 Bytes http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/305304 English eng Temple University Libraries TETDEDXMcKieKrisberg-temple-0225E-12009 http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/305304 The author has granted Temple University a limited, non-exclusive, royalty-free license to reproduce his or her dissertation, in whole or in part, in electronic or paper form and to make it available to the general public at no charge. This permission is granted in addition to rights granted to ProQuest. The author retains all other rights. Biology Biological oceanography Ecology Algae Bacterivory Cryptophyte Micromonas Mixotrophy Prasinophyte Dissertations 2014 fttempleunivdc 2024-01-15T19:31:43Z Biology Ph.D. Polar regions impose harsh conditions, including low temperatures, and prolonged periods of darkness on resident microbial communities. Despite these challenges, the conditions in these environments can also create opportunities for organisms utilizing combined trophic strategies (Mixotrophy). Only a limited number of studies have identified mixotrophic behavior in polar microbial eukaryotes, and even fewer studies have quantified the response of mixotrophs to likely environmental drivers of trophic behavior (light and nutrients). The goal of this work is to provide an identification of mixotrophic behavior and elucidate of some of the factors that influence algae isolated from polar environments. First, a study of the Arctic prasinophyte, Micromonas pusilla is presented in the first species-specific identification of mixotrophy in a eukaryotic phytoflagellate of this size class. M. pusilla grazed on bacteria under all experimental conditions, responding to nutrient limitation with increased rates of bacterivory. M. pusilla also showed evidence of prey selection. In contrast to the phagotrophic response, photosynthetic production was decreased under low-nutrient conditions. In an additional study of microbial eukaryotes from the Antarctic environment, identification of phagotrophy in photosynthetic nanoflagellates representing multiple evolutionary lineages: Cryptophyceae (Geminigera cryophila) and Prasinophyceae (Pyramimonas tychotreta and Mantoniella antarctica), showed that mixotrophy is more widespread in the Southern ocean that previously thought. G. cryophila and M. antarctica increased ingestions in dark treatments, but did not respond to difference in nutrient concentrations. In contrast, no significant grazing activity was observed in P. tychotreta under high nutrient conditions. When nutrients were reduced, ingestion of bacteria by P. tychotreta was observed and grazing increased in dark as compared to illuminated treatments. Finally, through a series of experimental assays, the ... Thesis Antarc* Antarctic Antarctica Arctic Southern Ocean Temple University Digital Collections Antarctic Arctic Southern Ocean The Antarctic |
institution |
Open Polar |
collection |
Temple University Digital Collections |
op_collection_id |
fttempleunivdc |
language |
English |
topic |
Biology Biological oceanography Ecology Algae Bacterivory Cryptophyte Micromonas Mixotrophy Prasinophyte |
spellingShingle |
Biology Biological oceanography Ecology Algae Bacterivory Cryptophyte Micromonas Mixotrophy Prasinophyte McKie-Krisberg, Zaid Mahira Phagotrophy in Photosynthetic Eukaryotic Microbes from Polar Environments |
topic_facet |
Biology Biological oceanography Ecology Algae Bacterivory Cryptophyte Micromonas Mixotrophy Prasinophyte |
description |
Biology Ph.D. Polar regions impose harsh conditions, including low temperatures, and prolonged periods of darkness on resident microbial communities. Despite these challenges, the conditions in these environments can also create opportunities for organisms utilizing combined trophic strategies (Mixotrophy). Only a limited number of studies have identified mixotrophic behavior in polar microbial eukaryotes, and even fewer studies have quantified the response of mixotrophs to likely environmental drivers of trophic behavior (light and nutrients). The goal of this work is to provide an identification of mixotrophic behavior and elucidate of some of the factors that influence algae isolated from polar environments. First, a study of the Arctic prasinophyte, Micromonas pusilla is presented in the first species-specific identification of mixotrophy in a eukaryotic phytoflagellate of this size class. M. pusilla grazed on bacteria under all experimental conditions, responding to nutrient limitation with increased rates of bacterivory. M. pusilla also showed evidence of prey selection. In contrast to the phagotrophic response, photosynthetic production was decreased under low-nutrient conditions. In an additional study of microbial eukaryotes from the Antarctic environment, identification of phagotrophy in photosynthetic nanoflagellates representing multiple evolutionary lineages: Cryptophyceae (Geminigera cryophila) and Prasinophyceae (Pyramimonas tychotreta and Mantoniella antarctica), showed that mixotrophy is more widespread in the Southern ocean that previously thought. G. cryophila and M. antarctica increased ingestions in dark treatments, but did not respond to difference in nutrient concentrations. In contrast, no significant grazing activity was observed in P. tychotreta under high nutrient conditions. When nutrients were reduced, ingestion of bacteria by P. tychotreta was observed and grazing increased in dark as compared to illuminated treatments. Finally, through a series of experimental assays, the ... |
author2 |
Sanders, Robert W.; Cordes, Erik E.; Nicholson, Allen W.; Gast, Rebecca J.; |
format |
Thesis |
author |
McKie-Krisberg, Zaid Mahira |
author_facet |
McKie-Krisberg, Zaid Mahira |
author_sort |
McKie-Krisberg, Zaid Mahira |
title |
Phagotrophy in Photosynthetic Eukaryotic Microbes from Polar Environments |
title_short |
Phagotrophy in Photosynthetic Eukaryotic Microbes from Polar Environments |
title_full |
Phagotrophy in Photosynthetic Eukaryotic Microbes from Polar Environments |
title_fullStr |
Phagotrophy in Photosynthetic Eukaryotic Microbes from Polar Environments |
title_full_unstemmed |
Phagotrophy in Photosynthetic Eukaryotic Microbes from Polar Environments |
title_sort |
phagotrophy in photosynthetic eukaryotic microbes from polar environments |
publisher |
Temple University Libraries |
publishDate |
2014 |
url |
http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/305304 |
geographic |
Antarctic Arctic Southern Ocean The Antarctic |
geographic_facet |
Antarctic Arctic Southern Ocean The Antarctic |
genre |
Antarc* Antarctic Antarctica Arctic Southern Ocean |
genre_facet |
Antarc* Antarctic Antarctica Arctic Southern Ocean |
op_relation |
TETDEDXMcKieKrisberg-temple-0225E-12009 http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/305304 |
op_rights |
The author has granted Temple University a limited, non-exclusive, royalty-free license to reproduce his or her dissertation, in whole or in part, in electronic or paper form and to make it available to the general public at no charge. This permission is granted in addition to rights granted to ProQuest. The author retains all other rights. |
_version_ |
1790601158584172544 |