Microbial polysaccharide utilization in sandy surface sediments
The shallow waters over continental shelves are a hotspot of marine primary production. In these regions, significant amounts of carbon fixed in the water column is exported to the sediment and, together with benthic primary production, feeds heterotrophic microbes. Much of the organic matter is com...
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Universität Bremen
2022
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ftsubbremen:oai:media.suub.uni-bremen.de:Publications/elib/7220 2023-10-09T21:56:11+02:00 Microbial polysaccharide utilization in sandy surface sediments Miksch, Sebastian Amann, Rudolf Mußman, Marc 2022-12-14 application/pdf https://media.suub.uni-bremen.de/handle/elib/7220 https://doi.org/10.26092/elib/2530 https://nbn-resolving.org/urn:nbn:de:gbv:46-elib72207 eng eng Universität Bremen Fachbereich 02: Biologie/Chemie (FB 02) https://media.suub.uni-bremen.de/handle/elib/7220 https://doi.org/10.26092/elib/2530 doi:10.26092/elib/2530 urn:nbn:de:gbv:46-elib72207 info:eu-repo/semantics/openAccess CC BY 4.0 (Attribution) https://creativecommons.org/licenses/by/4.0/ marine sediments marine microbiology molecular ecology Bioinformatic seasonality Svalbard polysaccharides 570 570 Life sciences biology ddc:570 Dissertation doctoralThesis 2022 ftsubbremen https://doi.org/10.26092/elib/2530 2023-09-17T22:09:42Z The shallow waters over continental shelves are a hotspot of marine primary production. In these regions, significant amounts of carbon fixed in the water column is exported to the sediment and, together with benthic primary production, feeds heterotrophic microbes. Much of the organic matter is comprised of polysaccharides produced by algae, which can be very complex. Since the organic matter is not accumulating, utilization of polysaccharides by benthic microbes must be highly relevant for the marine carbon cycle. In this thesis, I first studied the dynamics of benthic microbial communities in sands by assessing taxonomic changes over the seasonal cycle in temperate and polar regions. Compared to the rapid substrate driven successions of coastal bacterioplankton communities during and after spring blooms, there was very little seasonal change in the taxonomic composition of the benthic bacterial community. This comparison indicated fundamental differences in the ecological mechanisms driving pelagic and benthic communities. Since no taxonomic succession was observed, transcriptional activity was investigated. Here, clear seasonal changes were identified for several Gammaproteobacteria and Bacteroidia species. However, these species represented only a minor fraction of the community, with the majority showing relatively constant activity. Assessing the temporal changes in polysaccharides revealed α- and β-glucans as important substrates in winter and in spring, respectively, indicating that recycling processes might stabilize the community. Incubations with fluorescently labeled polysaccharides provided further evidence for β-glucan (laminarin) and animal-derived glycoprotein (mucin) utilization. The dominance of extracellular hydrolysis over selfish uptake in incubations and the high concentration of glucose-depleted dissolved organic matter in the pore water of sands, indicates that benthic microbes preferentially utilize glucose during the degradation of particulate organic matter, with the remaining glycans ... Doctoral or Postdoctoral Thesis Svalbard Media SuUB Bremen (Staats- und Universitätsbibliothek Bremen) Svalbard |
institution |
Open Polar |
collection |
Media SuUB Bremen (Staats- und Universitätsbibliothek Bremen) |
op_collection_id |
ftsubbremen |
language |
English |
topic |
marine sediments marine microbiology molecular ecology Bioinformatic seasonality Svalbard polysaccharides 570 570 Life sciences biology ddc:570 |
spellingShingle |
marine sediments marine microbiology molecular ecology Bioinformatic seasonality Svalbard polysaccharides 570 570 Life sciences biology ddc:570 Miksch, Sebastian Microbial polysaccharide utilization in sandy surface sediments |
topic_facet |
marine sediments marine microbiology molecular ecology Bioinformatic seasonality Svalbard polysaccharides 570 570 Life sciences biology ddc:570 |
description |
The shallow waters over continental shelves are a hotspot of marine primary production. In these regions, significant amounts of carbon fixed in the water column is exported to the sediment and, together with benthic primary production, feeds heterotrophic microbes. Much of the organic matter is comprised of polysaccharides produced by algae, which can be very complex. Since the organic matter is not accumulating, utilization of polysaccharides by benthic microbes must be highly relevant for the marine carbon cycle. In this thesis, I first studied the dynamics of benthic microbial communities in sands by assessing taxonomic changes over the seasonal cycle in temperate and polar regions. Compared to the rapid substrate driven successions of coastal bacterioplankton communities during and after spring blooms, there was very little seasonal change in the taxonomic composition of the benthic bacterial community. This comparison indicated fundamental differences in the ecological mechanisms driving pelagic and benthic communities. Since no taxonomic succession was observed, transcriptional activity was investigated. Here, clear seasonal changes were identified for several Gammaproteobacteria and Bacteroidia species. However, these species represented only a minor fraction of the community, with the majority showing relatively constant activity. Assessing the temporal changes in polysaccharides revealed α- and β-glucans as important substrates in winter and in spring, respectively, indicating that recycling processes might stabilize the community. Incubations with fluorescently labeled polysaccharides provided further evidence for β-glucan (laminarin) and animal-derived glycoprotein (mucin) utilization. The dominance of extracellular hydrolysis over selfish uptake in incubations and the high concentration of glucose-depleted dissolved organic matter in the pore water of sands, indicates that benthic microbes preferentially utilize glucose during the degradation of particulate organic matter, with the remaining glycans ... |
author2 |
Amann, Rudolf Mußman, Marc |
format |
Doctoral or Postdoctoral Thesis |
author |
Miksch, Sebastian |
author_facet |
Miksch, Sebastian |
author_sort |
Miksch, Sebastian |
title |
Microbial polysaccharide utilization in sandy surface sediments |
title_short |
Microbial polysaccharide utilization in sandy surface sediments |
title_full |
Microbial polysaccharide utilization in sandy surface sediments |
title_fullStr |
Microbial polysaccharide utilization in sandy surface sediments |
title_full_unstemmed |
Microbial polysaccharide utilization in sandy surface sediments |
title_sort |
microbial polysaccharide utilization in sandy surface sediments |
publisher |
Universität Bremen |
publishDate |
2022 |
url |
https://media.suub.uni-bremen.de/handle/elib/7220 https://doi.org/10.26092/elib/2530 https://nbn-resolving.org/urn:nbn:de:gbv:46-elib72207 |
geographic |
Svalbard |
geographic_facet |
Svalbard |
genre |
Svalbard |
genre_facet |
Svalbard |
op_relation |
https://media.suub.uni-bremen.de/handle/elib/7220 https://doi.org/10.26092/elib/2530 doi:10.26092/elib/2530 urn:nbn:de:gbv:46-elib72207 |
op_rights |
info:eu-repo/semantics/openAccess CC BY 4.0 (Attribution) https://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.26092/elib/2530 |
_version_ |
1779320728086118400 |