Do bacteria thrive when the ocean acidifies? Results from an off-shore mesocosm study
Marine bacteria are the main consumers of the freshly produced organic matter. In order to meet their carbon demand, bacteria release hydrolytic extracellular enzymes that break down large polymers into small usable subunits. Accordingly, rates of enzymatic hydrolysis have a high potential to affect...
Main Authors: | , , , , |
---|---|
Format: | Conference Object |
Language: | English |
Published: |
2014
|
Subjects: | |
Online Access: | https://oceanrep.geomar.de/id/eprint/25292/ https://oceanrep.geomar.de/id/eprint/25292/1/IMBER%20Future%20Oceans%20Conference.pdf http://www.imber.info/index.php/Meetings/IMBER-OSC-2014 |
id |
ftoceanrep:oai:oceanrep.geomar.de:25292 |
---|---|
record_format |
openpolar |
spelling |
ftoceanrep:oai:oceanrep.geomar.de:25292 2023-05-15T17:51:59+02:00 Do bacteria thrive when the ocean acidifies? Results from an off-shore mesocosm study Endres, Sonja Galgani, Luisa Riebesell, Ulf Schulz, Kai G. Engel, Anja 2014-06 text https://oceanrep.geomar.de/id/eprint/25292/ https://oceanrep.geomar.de/id/eprint/25292/1/IMBER%20Future%20Oceans%20Conference.pdf http://www.imber.info/index.php/Meetings/IMBER-OSC-2014 en eng https://oceanrep.geomar.de/id/eprint/25292/1/IMBER%20Future%20Oceans%20Conference.pdf Endres, S. , Galgani, L., Riebesell, U. , Schulz, K. G. and Engel, A. (2014) Do bacteria thrive when the ocean acidifies? Results from an off-shore mesocosm study. [Talk] In: IMBER Open Science Conference FUTURE OCEAN. , 23.-27.06.2014, Bergen, Norway . Conference or Workshop Item NonPeerReviewed 2014 ftoceanrep 2023-04-07T15:13:51Z Marine bacteria are the main consumers of the freshly produced organic matter. In order to meet their carbon demand, bacteria release hydrolytic extracellular enzymes that break down large polymers into small usable subunits. Accordingly, rates of enzymatic hydrolysis have a high potential to affect bacterial organic matter recycling and carbon turnover in the ocean. Many of these enzymatic processes were shown to be pH sensitive in previous studies. Due to the continuous rise in atmospheric CO2 concentration, seawater pH is presently decreasing at a rate unprecedented during the last 300 million years with so-far unknown consequences for microbial physiology, organic matter cycling and marine biogeochemistry. We studied the effects of elevated seawater pCO2 on a natural plankton community during a large-scale mesocosm study in a Norwegian fjord. Nine 25m-long Kiel Off-Shore Mesocosms for Future Ocean Simulations (KOSMOS) were adjusted to different pCO2 levels ranging from ca. 280 to 3000 µatm by stepwise addition of CO2 saturated seawater. After CO2 addition, samples were taken every second day for 34 days. The first phytoplankton bloom developed around day 5. On day 14, inorganic nutrients were added to the enclosed, nutrient-poor waters to stimulate a second phytoplankton bloom, which occurred around day 20. Our results indicate that marine bacteria benefit directly and indirectly from decreasing seawater pH. During both phytoplankton blooms, more transparent exopolymer particles were formed in the high pCO2 mesocosms. The total and cell-specific activities of the protein-degrading enzyme leucine aminopeptidase were elevated under low pH conditions. The combination of enhanced enzymatic hydrolysis of organic matter and increased availability of gel particles as substrate supported higher bacterial abundance in the high pCO2 treatments. We conclude that ocean acidification has the potential to stimulate the bacterial community and facilitate the microbial recycling of freshly produced organic matter, thus ... Conference Object Ocean acidification OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
institution |
Open Polar |
collection |
OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
op_collection_id |
ftoceanrep |
language |
English |
description |
Marine bacteria are the main consumers of the freshly produced organic matter. In order to meet their carbon demand, bacteria release hydrolytic extracellular enzymes that break down large polymers into small usable subunits. Accordingly, rates of enzymatic hydrolysis have a high potential to affect bacterial organic matter recycling and carbon turnover in the ocean. Many of these enzymatic processes were shown to be pH sensitive in previous studies. Due to the continuous rise in atmospheric CO2 concentration, seawater pH is presently decreasing at a rate unprecedented during the last 300 million years with so-far unknown consequences for microbial physiology, organic matter cycling and marine biogeochemistry. We studied the effects of elevated seawater pCO2 on a natural plankton community during a large-scale mesocosm study in a Norwegian fjord. Nine 25m-long Kiel Off-Shore Mesocosms for Future Ocean Simulations (KOSMOS) were adjusted to different pCO2 levels ranging from ca. 280 to 3000 µatm by stepwise addition of CO2 saturated seawater. After CO2 addition, samples were taken every second day for 34 days. The first phytoplankton bloom developed around day 5. On day 14, inorganic nutrients were added to the enclosed, nutrient-poor waters to stimulate a second phytoplankton bloom, which occurred around day 20. Our results indicate that marine bacteria benefit directly and indirectly from decreasing seawater pH. During both phytoplankton blooms, more transparent exopolymer particles were formed in the high pCO2 mesocosms. The total and cell-specific activities of the protein-degrading enzyme leucine aminopeptidase were elevated under low pH conditions. The combination of enhanced enzymatic hydrolysis of organic matter and increased availability of gel particles as substrate supported higher bacterial abundance in the high pCO2 treatments. We conclude that ocean acidification has the potential to stimulate the bacterial community and facilitate the microbial recycling of freshly produced organic matter, thus ... |
format |
Conference Object |
author |
Endres, Sonja Galgani, Luisa Riebesell, Ulf Schulz, Kai G. Engel, Anja |
spellingShingle |
Endres, Sonja Galgani, Luisa Riebesell, Ulf Schulz, Kai G. Engel, Anja Do bacteria thrive when the ocean acidifies? Results from an off-shore mesocosm study |
author_facet |
Endres, Sonja Galgani, Luisa Riebesell, Ulf Schulz, Kai G. Engel, Anja |
author_sort |
Endres, Sonja |
title |
Do bacteria thrive when the ocean acidifies? Results from an off-shore mesocosm study |
title_short |
Do bacteria thrive when the ocean acidifies? Results from an off-shore mesocosm study |
title_full |
Do bacteria thrive when the ocean acidifies? Results from an off-shore mesocosm study |
title_fullStr |
Do bacteria thrive when the ocean acidifies? Results from an off-shore mesocosm study |
title_full_unstemmed |
Do bacteria thrive when the ocean acidifies? Results from an off-shore mesocosm study |
title_sort |
do bacteria thrive when the ocean acidifies? results from an off-shore mesocosm study |
publishDate |
2014 |
url |
https://oceanrep.geomar.de/id/eprint/25292/ https://oceanrep.geomar.de/id/eprint/25292/1/IMBER%20Future%20Oceans%20Conference.pdf http://www.imber.info/index.php/Meetings/IMBER-OSC-2014 |
genre |
Ocean acidification |
genre_facet |
Ocean acidification |
op_relation |
https://oceanrep.geomar.de/id/eprint/25292/1/IMBER%20Future%20Oceans%20Conference.pdf Endres, S. , Galgani, L., Riebesell, U. , Schulz, K. G. and Engel, A. (2014) Do bacteria thrive when the ocean acidifies? Results from an off-shore mesocosm study. [Talk] In: IMBER Open Science Conference FUTURE OCEAN. , 23.-27.06.2014, Bergen, Norway . |
_version_ |
1766159296025853952 |