Drivers of Population Dynamics in Bacterioplankton : Spotlight on Alphaproteobacteria and its dominant SAR11 Lineage
Bacteria are mediators of biogeochemical cycles and are in this way vital for maintaining life on earth. Their distribution, abundance and functioning are driven by environmental heterogeneity and dynamic change in abiotic and biotic factors. Both, freshwater lakes and oceans play central roles in t...
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Uppsala universitet, Limnologi
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ftuppsalauniv:oai:DiVA.org:uu-245072 2023-05-15T18:25:16+02:00 Drivers of Population Dynamics in Bacterioplankton : Spotlight on Alphaproteobacteria and its dominant SAR11 Lineage Heinrich, Friederike 2015 application/pdf http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-245072 eng eng Uppsala universitet, Limnologi Uppsala Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, 1651-6214 1230 http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-245072 urn:isbn:978-91-554-9172-7 info:eu-repo/semantics/openAccess bacterial community dynamics Alphaproteobacteria SAR11 LD12 Southern Ocean lakes Doctoral thesis, comprehensive summary info:eu-repo/semantics/doctoralThesis text 2015 ftuppsalauniv 2023-02-23T21:39:57Z Bacteria are mediators of biogeochemical cycles and are in this way vital for maintaining life on earth. Their distribution, abundance and functioning are driven by environmental heterogeneity and dynamic change in abiotic and biotic factors. Both, freshwater lakes and oceans play central roles in the global carbon cycle and bacteria in these systems perform many services for the ecosystems, such as the transfer of organic carbon from primary producers to higher trophic levels. With estimated relative abundances up to 50% of the total bacterioplankton, the Alphaproteobacteria lineage SAR11 is the most abundant group of aquatic bacteria. It is globally distributed and can be partitioned into multiple sub-clades, one of which is exclusive to freshwaters. Until recently, the distribution, abundance and ecological role of this freshwater SAR11 named LD12 was unknown. The aim of the thesis was to study the drivers and mechanisms that influence the dynamics of aquatic bacterial communities in general and the SAR11 and LD12 groups in particular. The thesis consists of environmental surveys of a mesotrophic Lake Erken and the western Southern Ocean, an experiment and a data-mining exercise to reveal the phylogenetic structure of the SAR11 lineage on various temporal and spatial scales. The analysis of a long-term bacterioplankton community survey in lake Erken provided insights about the dynamics of the entire bacterial community and the LD12 population over an annual cycle. The results demonstrate that LD12 can be an equally abundant member of freshwater communities as marine SAR11 in oceans. LD12 featured strong seasonality and was positively coupled to environmental conditions indicative for an oligotrophic lifestyle. LD12 as well as other dominant lake bacterioplankton also maintained stable populations throughout spatial and temporal varying environments, but at high phylogenetic resolution, habitat preferences were revealed, particularly in response to oxygen concentrations. The later was not the case in LD12 as a ... Doctoral or Postdoctoral Thesis Southern Ocean Uppsala University: Publications (DiVA) Southern Ocean |
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collection |
Uppsala University: Publications (DiVA) |
op_collection_id |
ftuppsalauniv |
language |
English |
topic |
bacterial community dynamics Alphaproteobacteria SAR11 LD12 Southern Ocean lakes |
spellingShingle |
bacterial community dynamics Alphaproteobacteria SAR11 LD12 Southern Ocean lakes Heinrich, Friederike Drivers of Population Dynamics in Bacterioplankton : Spotlight on Alphaproteobacteria and its dominant SAR11 Lineage |
topic_facet |
bacterial community dynamics Alphaproteobacteria SAR11 LD12 Southern Ocean lakes |
description |
Bacteria are mediators of biogeochemical cycles and are in this way vital for maintaining life on earth. Their distribution, abundance and functioning are driven by environmental heterogeneity and dynamic change in abiotic and biotic factors. Both, freshwater lakes and oceans play central roles in the global carbon cycle and bacteria in these systems perform many services for the ecosystems, such as the transfer of organic carbon from primary producers to higher trophic levels. With estimated relative abundances up to 50% of the total bacterioplankton, the Alphaproteobacteria lineage SAR11 is the most abundant group of aquatic bacteria. It is globally distributed and can be partitioned into multiple sub-clades, one of which is exclusive to freshwaters. Until recently, the distribution, abundance and ecological role of this freshwater SAR11 named LD12 was unknown. The aim of the thesis was to study the drivers and mechanisms that influence the dynamics of aquatic bacterial communities in general and the SAR11 and LD12 groups in particular. The thesis consists of environmental surveys of a mesotrophic Lake Erken and the western Southern Ocean, an experiment and a data-mining exercise to reveal the phylogenetic structure of the SAR11 lineage on various temporal and spatial scales. The analysis of a long-term bacterioplankton community survey in lake Erken provided insights about the dynamics of the entire bacterial community and the LD12 population over an annual cycle. The results demonstrate that LD12 can be an equally abundant member of freshwater communities as marine SAR11 in oceans. LD12 featured strong seasonality and was positively coupled to environmental conditions indicative for an oligotrophic lifestyle. LD12 as well as other dominant lake bacterioplankton also maintained stable populations throughout spatial and temporal varying environments, but at high phylogenetic resolution, habitat preferences were revealed, particularly in response to oxygen concentrations. The later was not the case in LD12 as a ... |
format |
Doctoral or Postdoctoral Thesis |
author |
Heinrich, Friederike |
author_facet |
Heinrich, Friederike |
author_sort |
Heinrich, Friederike |
title |
Drivers of Population Dynamics in Bacterioplankton : Spotlight on Alphaproteobacteria and its dominant SAR11 Lineage |
title_short |
Drivers of Population Dynamics in Bacterioplankton : Spotlight on Alphaproteobacteria and its dominant SAR11 Lineage |
title_full |
Drivers of Population Dynamics in Bacterioplankton : Spotlight on Alphaproteobacteria and its dominant SAR11 Lineage |
title_fullStr |
Drivers of Population Dynamics in Bacterioplankton : Spotlight on Alphaproteobacteria and its dominant SAR11 Lineage |
title_full_unstemmed |
Drivers of Population Dynamics in Bacterioplankton : Spotlight on Alphaproteobacteria and its dominant SAR11 Lineage |
title_sort |
drivers of population dynamics in bacterioplankton : spotlight on alphaproteobacteria and its dominant sar11 lineage |
publisher |
Uppsala universitet, Limnologi |
publishDate |
2015 |
url |
http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-245072 |
geographic |
Southern Ocean |
geographic_facet |
Southern Ocean |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_relation |
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, 1651-6214 1230 http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-245072 urn:isbn:978-91-554-9172-7 |
op_rights |
info:eu-repo/semantics/openAccess |
_version_ |
1766206582281994240 |