Carbon dioxide-concentrating mechanism and the development of extracellular carbonic anhydrase in the marine picoeukaryote Micromonas pusilla.
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| Title: | Carbon dioxide-concentrating mechanism and the development of extracellular carbonic anhydrase in the marine picoeukaryote Micromonas pusilla. |
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| Authors: | Iglesias-Rodríguez, M. D.1 M.D.Iglesias-Rodriguez@bristol.ac.uk, Nimer, N. A.1, Merrett, M. J.1 |
| Source: | New Phytologist. Dec98, Vol. 140 Issue 4, p685-690. 6p. |
| Subjects: | Carbonic anhydrase, Marine phytoplankton, Carbon dioxide, Kinetic theory of gases, Photosynthesis, Acclimatization |
| Abstract: | A range of marine photosynthetic picoeukaryote phytoplankton species grown in culture were screened for the presence of extracellular carbonic anhydrase (CAext), a key enzyme in inorganic carbon acquisition under carbon-limiting conditions in some larger marine phytoplankton species. Of the species tested, extracellular carbonic anhydrase was detected only in Micromonas pusilla Butcher. The rapid, light-dependent development of CAext when cells were transferred from carbon-replete to carbon-limiting conditions was regulated by the available free- CO2 concentration and not by total dissolved inorganic carbon. Kinetic studies provided support for a CO2- concentrating mechanism in that the K0.5[CO2] (i.e. the CO2 concentration required for the half-maximal rate of photosynthesis) was substantially lower than the Km[CO2] of Rubisco from related taxa, whilst the intracellular carbon pool was at least seven fold greater than the extracellular DIC concentration, for extracellular DIC values 1.0 m m. It is proposed that when the flux of COCO2 into the cell is insufficient to support the photosynthetic rate at an optimum photon irradiance, the development of CAext increases the availability of CO2 at the plasma membrane. This ensures rapid acclimation to environmental change and provides an explanation for the central role of M. pusilla as a carbon sink in oligotrophic environments. [ABSTRACT FROM AUTHOR] |
| Copyright of New Phytologist is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
| Database: | Engineering Source |
| FullText | Text: Availability: 0 |
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| Header | DbId: egs DbLabel: Engineering Source An: 12734222 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
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| Items | – Name: Title Label: Title Group: Ti Data: Carbon dioxide-concentrating mechanism and the development of extracellular carbonic anhydrase in the marine picoeukaryote <em>Micromonas pusilla</em>. – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Iglesias-Rodríguez%2C+M%2E+D%2E%22">Iglesias-Rodríguez, M. D.</searchLink><relatesTo>1</relatesTo><i> M.D.Iglesias-Rodriguez@bristol.ac.uk</i><br /><searchLink fieldCode="AR" term="%22Nimer%2C+N%2E+A%2E%22">Nimer, N. A.</searchLink><relatesTo>1</relatesTo><br /><searchLink fieldCode="AR" term="%22Merrett%2C+M%2E+J%2E%22">Merrett, M. J.</searchLink><relatesTo>1</relatesTo> – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22New+Phytologist%22">New Phytologist</searchLink>. Dec98, Vol. 140 Issue 4, p685-690. 6p. – Name: Subject Label: Subjects Group: Su Data: <searchLink fieldCode="DE" term="%22Carbonic+anhydrase%22">Carbonic anhydrase</searchLink><br /><searchLink fieldCode="DE" term="%22Marine+phytoplankton%22">Marine phytoplankton</searchLink><br /><searchLink fieldCode="DE" term="%22Carbon+dioxide%22">Carbon dioxide</searchLink><br /><searchLink fieldCode="DE" term="%22Kinetic+theory+of+gases%22">Kinetic theory of gases</searchLink><br /><searchLink fieldCode="DE" term="%22Photosynthesis%22">Photosynthesis</searchLink><br /><searchLink fieldCode="DE" term="%22Acclimatization%22">Acclimatization</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: A range of marine photosynthetic picoeukaryote phytoplankton species grown in culture were screened for the presence of extracellular carbonic anhydrase (CAext), a key enzyme in inorganic carbon acquisition under carbon-limiting conditions in some larger marine phytoplankton species. Of the species tested, extracellular carbonic anhydrase was detected only in <em>Micromonas pusilla</em> Butcher. The rapid, light-dependent development of CAext when cells were transferred from carbon-replete to carbon-limiting conditions was regulated by the available free- CO2 concentration and not by total dissolved inorganic carbon. Kinetic studies provided support for a CO2- concentrating mechanism in that the K0.5[CO2] (i.e. the CO2 concentration required for the half-maximal rate of photosynthesis) was substantially lower than the Km[CO2] of Rubisco from related taxa, whilst the intracellular carbon pool was at least seven fold greater than the extracellular DIC concentration, for extracellular DIC values 1.0 m m. It is proposed that when the flux of COCO2 into the cell is insufficient to support the photosynthetic rate at an optimum photon irradiance, the development of CAext increases the availability of CO2 at the plasma membrane. This ensures rapid acclimation to environmental change and provides an explanation for the central role of <em>M. pusilla</em> as a carbon sink in oligotrophic environments. [ABSTRACT FROM AUTHOR] – Name: AbstractSuppliedCopyright Label: Group: Ab Data: <i>Copyright of New Phytologist is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.) |
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| RecordInfo | BibRecord: BibEntity: Identifiers: – Type: doi Value: 10.1046/j.1469-8137.1998.00309.x Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 6 StartPage: 685 Subjects: – SubjectFull: Carbonic anhydrase Type: general – SubjectFull: Marine phytoplankton Type: general – SubjectFull: Carbon dioxide Type: general – SubjectFull: Kinetic theory of gases Type: general – SubjectFull: Photosynthesis Type: general – SubjectFull: Acclimatization Type: general Titles: – TitleFull: Carbon dioxide-concentrating mechanism and the development of extracellular carbonic anhydrase in the marine picoeukaryote <em>Micromonas pusilla</em>. Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Iglesias-Rodríguez, M. D. – PersonEntity: Name: NameFull: Nimer, N. A. – PersonEntity: Name: NameFull: Merrett, M. J. IsPartOfRelationships: – BibEntity: Dates: – D: 01 M: 12 Text: Dec98 Type: published Y: 1998 Identifiers: – Type: issn-print Value: 0028646X Numbering: – Type: volume Value: 140 – Type: issue Value: 4 Titles: – TitleFull: New Phytologist Type: main |
| ResultId | 1 |
