Navigation Links
Mystery dissolves with calcium pump discovery
Date:11/30/2010

Geo-microbiologists from Arizona State University have solved a long-standing conundrum about how some photosynthetic microorganisms, endolithic cyanobacteria, bore their way into limestone, sand grains, mussel shells, coral skeletons and other substrates composed of carbonate.

According to the lead investigator, ASU professor Ferran Garcia-Pichel, the answer to the mystery of what is "at the heart of an erosive force of global proportions" is a calcium-driven pump, similar to that which we use to power our muscles.

The results of Garcia-Pichel's study "Microbial excavation of solid carbonates powered by P-type ATPase-mediate transcellular Ca 2+ transport" were published Nov. 29 in the Proceedings of the National Academy of Sciences (PNAS).

While the dissolution of the carbonate coral reefs was noted more than a century ago by Louis Agassiz, the father of American naturalists, the specifics of how this physiological process occurs has remained a mystery. In fact, the process has presented a geochemical paradox to scientists, in that most cyanobacteria tend to precipitate new carbonates, not dissolve them.

Typically cyanobacteria, by photosynthesizing, raise the pH of the water (and lower the acidity); this process typically causes carbonate to precipitate if the change is large enough. While that is the "normal" case, the paradox with boring cyanobacteria is that photosynthesis occurs at the same time that they dissolve carbonate structures (which typically requires the pH to go down, making the environment more, rather than less acidic).

Garcia-Pichel and coauthors, Edgardo Ramrez-Reinat, a doctoral candidate, and Qunjie Gao, a faculty research associate, in the School of Life Sciences in ASU's College of Liberal Arts and Sciences, set about trying to understand how this select group of carbonate-boring species can excavate by coaxing a strain of Mastigocoleus testarum, a filamentous, branching cyanobacterium, to grow in the laboratory under controlled conditions. Using real-time microscopic examinations, including calcium imaging and photosynthetic analysis, coupled with molecular genetics, the trio examined the cyanobacteria's invasion of calcite chips and the physiological mechanisms at play.

The ASU group found supersaturation of calcium near the surface of the borehole, but undersaturation at the boring front. This finding meant that the mass transfer of calcium could not happen extracellularly, by diffusion in the bored hole, which would require calcium to move against a concentration gradient.

Instead, they discovered that the endolithic cyanobacteria took up calcium from the tips of their boring filaments, directly into their cells. This action promoted the localized dissolution of the calcium-containing carbonate substrate. The calcium was then transported from cell to cell away from the area being quarried, and finally excreted at the entrance of a borehole. The consequences of this transient, but significantly high, concentration of intracellular calcium in the cells remains a question that the Garcia-Pichel laboratory hopes to pursue.

Garcia-Pichel says that he hopes that the newly gained knowledge allows the scientists to explain a variety of geological phenomena and points to new research directions to combat microbial pests of shellfish, such as cultured mussels.

"While it is hard to quantify the losses to the shellfish industry, the impact of endolithic bacteria has been described as a plague by Canadian fisheries," says Garcia-Pichel. "We have identified compounds that abolish the boring activity by inhibiting the enzymatic calcium pumps involved in the process, which may be implemented eventually to protect targets, either by direct application or through genetic engineering of the mussels."

Such studies as these will also help researchers to understand the impact of changes in calcium saturation states of ocean waters, says Garcia-Pichel, which are driven by increased atmospheric carbon dioxide. These are expected to result in a global enhancement of bioerosion, including the already impacted coral reefs.

Ferran Garcia-Pichel and his colleagues' laboratory studies will now also translate to their field research, where they will try and quantify the effect of ocean acidification on cyanobacterial borings. They will also pursue studies of other endolithic cyanobacteria, and other minerals, such as dolomites, calcophosphates and magnesites.


'/>"/>

Contact: Margaret Coulombe
Margaret.Coulombe@asu.edu
480-727-8934
Arizona State University
Source:Eurekalert  

Related biology news :

1. VIMS scientists help solve mystery of alien pod
2. A mystery solved: How genes are selectively silenced
3. Scientists solve mystery of arsenic compound
4. Marine scientists unveil the mystery of life on undersea mountains
5. Toward resolving Darwins abominable mystery
6. Interdisciplinary research looks at Charlottes green mystery
7. Mystery unraveled: How asbestos causes cancer
8. Answer to saliva mystery has practical impact
9. Solution to beading-saliva mystery has practical purposes
10. Uncovering the mystery of a major threat to wheat
11. A Dicty mystery solved
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Mystery dissolves with calcium pump discovery
(Date:3/31/2016)... BOCA RATON, Florida , March 31, 2016 /PRNewswire/ ... LEGX ) ("LegacyXChange" or the "Company") ... presentation for potential users of its soon to be ... The video ( https://www.youtube.com/channel/UCyTLBzmZogV1y2D6bDkBX5g ) will also ... by the use of DNA technology to an industry ...
(Date:3/23/2016)... 23, 2016 ... Gesichts- und Stimmerkennung mit Passwörtern     ... MESG ), ein führender Anbieter digitaler ... mit SpeechPro zusammenarbeitet, um erstmals dessen Biometrietechnologie ... die Möglichkeit angeboten, im Rahmen mobiler Apps ...
(Date:3/21/2016)... -- Unique technology combines v ...   Xura, Inc. (NASDAQ: ... communications services, today announced it is working alongside SpeechPro ... particularly those in the Financial Services Sector, the ability ... a mobile app, alongside, and in combination with, traditional ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... ... 23, 2016 , ... Mosio, a leader in clinical research ... Recruitment and Retention Tips.” Partnering with experienced clinical research professionals, Mosio revisits the ... tools, and strategies for clinical researchers. , “The landscape of how patients receive ...
(Date:6/23/2016)... TORONTO , June 23, 2016 /PRNewswire/ - ... Ontario biotechnology company, Propellon ... the development and commercialization of a portfolio of ... cancers. Epigenetic targets such as WDR5 represent an ... contribute significantly in precision medicine for cancer patients. ...
(Date:6/23/2016)... ... June 23, 2016 , ... Charm Sciences, Inc. is ... has received AOAC Research Institute approval 061601. , “This is another AOAC-RI approval ... Bob Salter, Vice President of Regulatory and Industrial Affairs. “The Peel Plate methods ...
(Date:6/23/2016)... --  EpiBiome , a precision microbiome engineering company, today ... from Silicon Valley Bank (SVB). The financing will allow ... drug development efforts, as well as purchase additional lab ... been an incredible strategic partner to us – one ... provide," said Dr. Aeron Tynes Hammack , EpiBiome,s ...
Breaking Biology Technology: