Navigation Links
Surprises from the ocean: Marine plankton and ocean pH
Date:6/21/2011

The world's oceans support vast populations of single-celled organisms (phytoplankton) that are responsible, through photosynthesis, for removing about half of the carbon dioxide that is produced by burning fossil fuels as much as the rainforests and all other terrestrial systems combined. One group of phytoplankton, known as the coccolithophores, are known for their remarkable ability to build chalk (calcium carbonate) scales inside their cells, which are secreted to form a protective armour on the cell surface. On a global scale this calcification process accounts for a very significant flux of carbon from the surface ocean, and hence coccolithophores are an important component of the global carbon cycle, as cells die and the calcium carbonate sinks to form ocean sediments.

In an article published in PLoS Biology on 21st June, a team of scientists from the Marine Biological Association and Plymouth Marine Laboratory in the UK and the University of North Carolina Wilmington, USA report the unexpected finding that coccolithophores use a similar mechanism to the one previously characterised in vertebrate cells, to facilitate calcification. They found that this process may be directly affected by the current increasing levels of dissolved carbon dioxide in the oceans.

The armour scales of coccolithophores are formed by transporting calcium and bicarbonate into the cell where they combine to form calcium carbonate. Calcification is a strongly pH-dependent process and is likely to be affected by the increase in carbon dioxide levels that are making the ocean increasingly acidic.

The researchers used a combination of single cell physiology and molecular biology to identify the molecular machinery that underlies calcification. A by-product of the calcification reaction is the formation of protons (H+) inside the cell. "These H+ ions can potentially accumulate in the cell causing it to become acidic - a process known as metabolic acidosis" says Alison Taylor, article author. Cells use a variety of pH-regulatory processes to alleviate the burden of excessive H+ ions. The team showed that coccolithophores dispose of unwanted H+ by allowing them to exit cells through specialised protein pores, or ion channels, that are selectively permeable to H+. This process keeps the pH inside the cells at acceptable levels and allows coccolithophores to produce their calcium carbonate scales.

The team identified the gene that encodes for the H+ channel protein. "These H+ channels belong to a unique group of transport proteins that were discovered quite recently in certain types of animal cells that experience metabolic acidosis" explains Glen Wheeler, co-author of the study. "It turns out that H+ channel genes are also present in other groups of phytoplankton [which] belong to groups that are not closely related to either plants or animals. Our discovery shows that H+ channels are more widespread than previously thought and that they serve a critical function in regulating cellular pH during a range of cellular processes in evolutionarily distant organisms" says Wheeler.

"A key finding of the work is that H+ channel activity in coccolithophores is dependent on external pH", explains Colin Brownlee of the Marine Biological Association. "The findings will ultimately allow a better understanding of how [phytoplankton] respond to changes in ocean chemistry due to increased dissolution of atmospheric carbon dioxide in the oceans' surface waters."


'/>"/>

Contact: Bryan Ghosh
bghosh@plos.org
44-122-344-2837
Public Library of Science
Source:Eurekalert

Related biology news :

1. Seeing the brain hear reveals surprises about how sound is processed
2. Natural selection for moderate testosterone surprises scientists
3. Low elevations hold climate surprises
4. Genome of barley disease reveals surprises
5. Icy meltwater pooling in Arctic Ocean: A wild card in climate change scenarios
6. Effects of anthropogenic sound on marine mammals -- a research strategy
7. The Marine Mammal Center begins new leptospirosis study in California
8. Scientists announce major progress towards historic Census of Marine Life in 2010
9. Marine invasive species advance 50km per decade, World Conference on Marine Biodiversity told
10. Marine invasive species advance 50 km per decade, World Conference on Marine Biodiversity told
11. Snowy owl -- a marine species?
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/11/2017)... , April 11, 2017 NXT-ID, ... security technology company, announces the appointment of independent Directors Mr. ... to its Board of Directors, furthering the company,s corporate ... ... NXT-ID, we look forward to their guidance and benefiting from ...
(Date:4/5/2017)... -- The Allen Institute for Cell Science today announces the ... and dynamic digital window into the human cell. The ... of deep learning to create predictive models of cell ... growing suite of powerful tools. The Allen Cell Explorer ... available resources created and shared by the Allen Institute ...
(Date:4/5/2017)... 2017 KEY FINDINGS The global ... a CAGR of 25.76% during the forecast period of ... factor for the growth of the stem cell market. ... MARKET INSIGHTS The global stem cell market is ... geography. The stem cell market of the product is ...
Breaking Biology News(10 mins):
(Date:10/12/2017)... ... October 12, 2017 , ... AMRI, ... and biotechnology industries to improve patient outcomes and quality of life, will now ... testing are being attributed to new regulatory requirements for all new drug products, ...
(Date:10/11/2017)... ... ... wash is a basic first aid supply for any work environment, but most personal eye ... first if a dangerous substance enters both eyes? It’s one less decision, and likely quicker ... eye piece. , “Whether its dirt and debris, or an acid or alkali, getting anything ...
(Date:10/11/2017)... ROTTERDAM, the Netherlands and LAGUNA HILLS, ... that The Institute of Cancer Research, London ... will use MMprofiler™ with SKY92, SkylineDx,s prognostic tool to risk-stratify ... high-risk trial known as MUK nine . The University ... this trial, which is partly funded by Myeloma UK, and ...
(Date:10/10/2017)... ... October 10, 2017 , ... San Diego-based team building and cooking ... initiative announced today. The bold new look is part of a transformation to ... into a significant growth period. , It will also expand its service offering from ...
Breaking Biology Technology: