Cargando…

Virus Dynamics Are Influenced by Season, Tides and Advective Transport in Intertidal, Permeable Sediments

Sandy surface sediments of tidal flats exhibit high microbial activity due to the fast and deep-reaching transport of oxygen and nutrients by porewater advection. On the other hand during low tide, limited transport results in nutrient and oxygen depletion concomitant to the accumulation of microbia...

Descripción completa

Detalles Bibliográficos
Autores principales: Vandieken, Verona, Sabelhaus, Lara, Engelhardt, Tim
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2017
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5741694/
https://www.ncbi.nlm.nih.gov/pubmed/29326673
http://dx.doi.org/10.3389/fmicb.2017.02526
_version_ 1783288229298962432
author Vandieken, Verona
Sabelhaus, Lara
Engelhardt, Tim
author_facet Vandieken, Verona
Sabelhaus, Lara
Engelhardt, Tim
author_sort Vandieken, Verona
collection PubMed
description Sandy surface sediments of tidal flats exhibit high microbial activity due to the fast and deep-reaching transport of oxygen and nutrients by porewater advection. On the other hand during low tide, limited transport results in nutrient and oxygen depletion concomitant to the accumulation of microbial metabolites. This study represents the first attempt to use flow-through reactors to investigate virus production, virus transport and the impact of tides and season in permeable sediments. The reactors were filled with intertidal sands of two sites (North beach site and backbarrier sand flat of Spiekeroog island in the German Wadden Sea) to best simulate advective porewater transport through the sediments. Virus and cell release along with oxygen consumption were measured in the effluents of reactors during continuous flow of water through the sediments as well as in tidal simulation experiments where alternating cycles with and without water flow (each for 6 h) were operated. The results showed net rates of virus production (0.3–13.2 × 10(6) viruses cm(−3) h(−1)) and prokaryotic cell production (0.3–10.0 × 10(5) cells cm(−3) h(−1)) as well as oxygen consumption rates (56–737 μmol l(−1) h(−1)) to be linearly correlated reflecting differences in activity, season and location of the sediments. Calculations show that total virus turnover was fast with 2 to 4 days, whereas virus-mediated cell turnover was calculated to range between 5–13 or 33–91 days depending on the assumed burst sizes (number of viruses released upon cell lysis) of 14 or 100 viruses, respectively. During the experiments, the homogenized sediments in the reactors became vertically structured with decreasing microbial activities and increasing impact of viruses on prokaryotic mortality with depth. Tidal simulation clearly showed a strong accumulation of viruses and cells in the top sections of the reactors when the flow was halted indicating a consistently high virus production during low tide. In conclusion, cell lysis products due to virus production may fuel microbial communities in the absence of advection-driven nutrient input, but are eventually washed off the surface sediment during high tide and being transported into deeper sediment layers or into the water column together with the produced viruses.
format Online
Article
Text
id pubmed-5741694
institution National Center for Biotechnology Information
language English
publishDate 2017
publisher Frontiers Media S.A.
record_format MEDLINE/PubMed
spelling pubmed-57416942018-01-11 Virus Dynamics Are Influenced by Season, Tides and Advective Transport in Intertidal, Permeable Sediments Vandieken, Verona Sabelhaus, Lara Engelhardt, Tim Front Microbiol Microbiology Sandy surface sediments of tidal flats exhibit high microbial activity due to the fast and deep-reaching transport of oxygen and nutrients by porewater advection. On the other hand during low tide, limited transport results in nutrient and oxygen depletion concomitant to the accumulation of microbial metabolites. This study represents the first attempt to use flow-through reactors to investigate virus production, virus transport and the impact of tides and season in permeable sediments. The reactors were filled with intertidal sands of two sites (North beach site and backbarrier sand flat of Spiekeroog island in the German Wadden Sea) to best simulate advective porewater transport through the sediments. Virus and cell release along with oxygen consumption were measured in the effluents of reactors during continuous flow of water through the sediments as well as in tidal simulation experiments where alternating cycles with and without water flow (each for 6 h) were operated. The results showed net rates of virus production (0.3–13.2 × 10(6) viruses cm(−3) h(−1)) and prokaryotic cell production (0.3–10.0 × 10(5) cells cm(−3) h(−1)) as well as oxygen consumption rates (56–737 μmol l(−1) h(−1)) to be linearly correlated reflecting differences in activity, season and location of the sediments. Calculations show that total virus turnover was fast with 2 to 4 days, whereas virus-mediated cell turnover was calculated to range between 5–13 or 33–91 days depending on the assumed burst sizes (number of viruses released upon cell lysis) of 14 or 100 viruses, respectively. During the experiments, the homogenized sediments in the reactors became vertically structured with decreasing microbial activities and increasing impact of viruses on prokaryotic mortality with depth. Tidal simulation clearly showed a strong accumulation of viruses and cells in the top sections of the reactors when the flow was halted indicating a consistently high virus production during low tide. In conclusion, cell lysis products due to virus production may fuel microbial communities in the absence of advection-driven nutrient input, but are eventually washed off the surface sediment during high tide and being transported into deeper sediment layers or into the water column together with the produced viruses. Frontiers Media S.A. 2017-12-18 /pmc/articles/PMC5741694/ /pubmed/29326673 http://dx.doi.org/10.3389/fmicb.2017.02526 Text en Copyright © 2017 Vandieken, Sabelhaus and Engelhardt. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
spellingShingle Microbiology
Vandieken, Verona
Sabelhaus, Lara
Engelhardt, Tim
Virus Dynamics Are Influenced by Season, Tides and Advective Transport in Intertidal, Permeable Sediments
title Virus Dynamics Are Influenced by Season, Tides and Advective Transport in Intertidal, Permeable Sediments
title_full Virus Dynamics Are Influenced by Season, Tides and Advective Transport in Intertidal, Permeable Sediments
title_fullStr Virus Dynamics Are Influenced by Season, Tides and Advective Transport in Intertidal, Permeable Sediments
title_full_unstemmed Virus Dynamics Are Influenced by Season, Tides and Advective Transport in Intertidal, Permeable Sediments
title_short Virus Dynamics Are Influenced by Season, Tides and Advective Transport in Intertidal, Permeable Sediments
title_sort virus dynamics are influenced by season, tides and advective transport in intertidal, permeable sediments
topic Microbiology
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5741694/
https://www.ncbi.nlm.nih.gov/pubmed/29326673
http://dx.doi.org/10.3389/fmicb.2017.02526
work_keys_str_mv AT vandiekenverona virusdynamicsareinfluencedbyseasontidesandadvectivetransportinintertidalpermeablesediments
AT sabelhauslara virusdynamicsareinfluencedbyseasontidesandadvectivetransportinintertidalpermeablesediments
AT engelhardttim virusdynamicsareinfluencedbyseasontidesandadvectivetransportinintertidalpermeablesediments