Friend or Foe? The influence of bacteria on the growth of the diatom Thallassiosira rotula.

Diatom-bacteria interactions are a crucial part of the global ocean and span from mutualistic via competitive to parasitic relationships. A lot of these interactions take place in the so-called “phycosphere” a diffusive boundary layer surrounding algal cells providing bacteria with a unique environm...

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Main Author: Drewes, Hannah Marie
Format: Thesis
Language:unknown
Published: 2022
Subjects:
Online Access:https://epic.awi.de/id/eprint/56704/
https://hdl.handle.net/10013/epic.19541f83-59cc-427e-92c8-6fa07777f283
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spelling ftawi:oai:epic.awi.de:56704 2023-05-15T15:15:07+02:00 Friend or Foe? The influence of bacteria on the growth of the diatom Thallassiosira rotula. Drewes, Hannah Marie 2022-07 https://epic.awi.de/id/eprint/56704/ https://hdl.handle.net/10013/epic.19541f83-59cc-427e-92c8-6fa07777f283 unknown Drewes, H. M. (2022) Friend or Foe? The influence of bacteria on the growth of the diatom Thallassiosira rotula. , Master thesis, University of Bremen. hdl:10013/epic.19541f83-59cc-427e-92c8-6fa07777f283 EPIC3105 p. Thesis NonPeerReviewed 2022 ftawi 2022-07-31T23:12:20Z Diatom-bacteria interactions are a crucial part of the global ocean and span from mutualistic via competitive to parasitic relationships. A lot of these interactions take place in the so-called “phycosphere” a diffusive boundary layer surrounding algal cells providing bacteria with a unique environment rich in algal-derived carbon sources. However, only few bacterial lines (Alpha-, Beta- and Gammaproteobacteria, Bacteroidetes) mainly genera such as Roseobacter, Sulfitobacter and Flavobacterium have been observed to reliably form symbiosis with diatom species. Thalassiosira rotula is a ubiquitous, bloom-forming, centric diatom found in a diverse number of marine habitats and was in this case isolated from a spring bloom event around the island of Helgoland. The main objective of this thesis was to investigate the influence of single strain bacteria on the growth of Thalassiosira rotula. To achieve this goal a co-cultivation method was designed that allowed for a high number of bacteria strains to be investigated at the same time. Moreover, it was investigated whether co-cultivation with two bacterial strains at the same time enhanced, diminished or did not affect the effect of single-strain bacteria on the growth of T. rotula. T. rotula was grown under vitamin-reduced conditions in Enriched Seawater, Artificial Water (ESAWred) in 24-well plates in co-cultivation with 33 bacterial strains isolated from the same spring bloom event or from the Arctic. Autofluorescence of algae was measured in a microplate reader as a proxy for algal growth over time. Moreover, two, dual-strain co-cultivations were conducted where T. rotula was combined with two different bacterial strains at the same time. During three single-strain co-cultivations it was observed that the designed method had two major sources of errors: 1) Algal growth was stunted by an unknown effect of MB medium introduced into cultures with bacterial inoculates 2) Bacterial OD600 varied greatly with the same dilution factor, therefore a fourth, improved ... Thesis Arctic Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) Arctic Helgoland
institution Open Polar
collection Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center)
op_collection_id ftawi
language unknown
description Diatom-bacteria interactions are a crucial part of the global ocean and span from mutualistic via competitive to parasitic relationships. A lot of these interactions take place in the so-called “phycosphere” a diffusive boundary layer surrounding algal cells providing bacteria with a unique environment rich in algal-derived carbon sources. However, only few bacterial lines (Alpha-, Beta- and Gammaproteobacteria, Bacteroidetes) mainly genera such as Roseobacter, Sulfitobacter and Flavobacterium have been observed to reliably form symbiosis with diatom species. Thalassiosira rotula is a ubiquitous, bloom-forming, centric diatom found in a diverse number of marine habitats and was in this case isolated from a spring bloom event around the island of Helgoland. The main objective of this thesis was to investigate the influence of single strain bacteria on the growth of Thalassiosira rotula. To achieve this goal a co-cultivation method was designed that allowed for a high number of bacteria strains to be investigated at the same time. Moreover, it was investigated whether co-cultivation with two bacterial strains at the same time enhanced, diminished or did not affect the effect of single-strain bacteria on the growth of T. rotula. T. rotula was grown under vitamin-reduced conditions in Enriched Seawater, Artificial Water (ESAWred) in 24-well plates in co-cultivation with 33 bacterial strains isolated from the same spring bloom event or from the Arctic. Autofluorescence of algae was measured in a microplate reader as a proxy for algal growth over time. Moreover, two, dual-strain co-cultivations were conducted where T. rotula was combined with two different bacterial strains at the same time. During three single-strain co-cultivations it was observed that the designed method had two major sources of errors: 1) Algal growth was stunted by an unknown effect of MB medium introduced into cultures with bacterial inoculates 2) Bacterial OD600 varied greatly with the same dilution factor, therefore a fourth, improved ...
format Thesis
author Drewes, Hannah Marie
spellingShingle Drewes, Hannah Marie
Friend or Foe? The influence of bacteria on the growth of the diatom Thallassiosira rotula.
author_facet Drewes, Hannah Marie
author_sort Drewes, Hannah Marie
title Friend or Foe? The influence of bacteria on the growth of the diatom Thallassiosira rotula.
title_short Friend or Foe? The influence of bacteria on the growth of the diatom Thallassiosira rotula.
title_full Friend or Foe? The influence of bacteria on the growth of the diatom Thallassiosira rotula.
title_fullStr Friend or Foe? The influence of bacteria on the growth of the diatom Thallassiosira rotula.
title_full_unstemmed Friend or Foe? The influence of bacteria on the growth of the diatom Thallassiosira rotula.
title_sort friend or foe? the influence of bacteria on the growth of the diatom thallassiosira rotula.
publishDate 2022
url https://epic.awi.de/id/eprint/56704/
https://hdl.handle.net/10013/epic.19541f83-59cc-427e-92c8-6fa07777f283
geographic Arctic
Helgoland
geographic_facet Arctic
Helgoland
genre Arctic
genre_facet Arctic
op_source EPIC3105 p.
op_relation Drewes, H. M. (2022) Friend or Foe? The influence of bacteria on the growth of the diatom Thallassiosira rotula. , Master thesis, University of Bremen. hdl:10013/epic.19541f83-59cc-427e-92c8-6fa07777f283
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