Regulation of inorganic carbon acquisition by phosphorus limitation in the green alga Chlorella emersonii

2005 ◽  
Vol 83 (7) ◽  
pp. 859-864 ◽  
Author(s):  
John Beardall ◽  
Simon Roberts ◽  
John A Raven
Keyword(s):  
Green Alga ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Stable Carbon Isotope ◽  
Phosphorus Limitation ◽  
Phosphate Limitation ◽  
P Limitation ◽  
Green Alga Chlorella ◽  
In Cells ◽  
Inorganic Carbon Acquisition

Inorganic phosphate (Pi) plays a central role in cellular energy transduction. As a consequence, limitation of growth by phosphate availability can have an important impact on various aspects of metabolism. Since carbon acquisition via CO2-concentrating mechanisms (CCMs) in most microalgae is an active process, requiring ATP, it might be expected that phosphate limitation could have an indirect regulatory influence on CCM activity. We grew the green alga Chlorella emersonii Shihira et Krauss in semicontinuous or continuous cultures in nutrient-replete conditions or with orthophosphate as the limiting nutrient. CCM activity was down-regulated by P limitation. K0.5(dissolved inorganic carbon) values increased from approximately 4.5 µmol·L–1 in cells growing at close to maximal rates to >12 µmol·L–1 in cells growing at 0.2 d–1. Maximal rates of photosynthesis decreased by approximately half over the same range of growth rates. Direct measurements of CCM activity showed that internal CO2 : external CO2 ratio was markedly decreased under P limitation, and concurrent measurements of stable carbon isotope discrimination were consistent with decreased CCM activity in the P-limited cells.Key words: phosphate, CCM, CO2-concentrating mechanism, Chlorella, inorganic carbon acquisition.

Active HCO3− transport in cyanobacteria

1991 ◽  
Vol 69 (5) ◽  
pp. 936-944 ◽  
Author(s):  
George S. Espie ◽  
Anthony G. Miller ◽  
Ramani A. Kandasamy ◽  
David T. Canvin
Keyword(s):  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Reaction Medium ◽  
Transport Systems ◽  
Bicarbonate Transport ◽  
Key Words Cyanobacteria ◽  
Sodium Dependent ◽  
Rate Of Photosynthesis ◽  
Low Levels ◽  
In Cells

Cyanobacteria possess systems for the active transport of both CO2 and HCO3−. While the active CO2 transport system seems to be present in cells grown on all levels of CO2 or dissolved inorganic carbon, the bicarbonate transport systems are only present in cells grown on low levels of CO2 or dissolved inorganic carbon (air levels or lower). Active bicarbonate transport can be shown to occur when the rate of photosynthesis exceeds that which could be sustained by the production of CO2 from the dehydration of bicarbonate or when CO2 transport is inhibited with carbon oxysulfide or hydrogen sulfide. Two systems for active bicarbonate transport have been identified: one is dependent on the presence of millimolar concentrations of sodium, and the other is independent of the sodium requirement. Cells grown with air bubbling normally possess the first whereas cells grown in standing culture normally possess the second. The sodium-dependent bicarbonate transport can be inhibited by omitting sodium from the reaction medium or competitively with lithium when sodium is present. Monensin and amiloride also inhibit sodium-dependent bicarbonate transport. It does not appear to be inhibited by ethoxyzolamide. The inhibition of sodium-independent bicarbonate transport is not yet established. Bicarbonate transport appears to have no effect on CO2 transport and CO2 transport appears to have no effect on bicarbonate transport. Hence, the transport systems seems to be independent. Although a number of mechanisms have been proposed for bicarbonate transport, the experimental data are not sufficient to clearly distinguish between them. Key words: cyanobacteria, active CO2 transport, active HCO3− transport, photosynthesis, sodium.

scholarly journals Measurements of the stable carbon isotope composition of dissolved inorganic carbon in the northeastern Atlantic and Nordic Seas during summer 2012

2015 ◽  
Vol 7 (1) ◽  
pp. 127-135 ◽  
Author(s):  
M. P. Humphreys ◽  
E. P. Achterberg ◽  
A. M. Griffiths ◽  
A. McDonald ◽  
A. J. Boyce
Keyword(s):  
Carbon Isotope ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Isotope Composition ◽  
Stable Carbon Isotope ◽  
Carbon Isotope Composition ◽  
Stable Carbon ◽  
Nordic Seas ◽  
Stable Carbon Isotope Composition ◽  
Northeastern Atlantic

Abstract. The stable carbon isotope composition of dissolved inorganic carbon (δ13CDIC) in seawater was measured in a batch process for 552 samples collected during two cruises in the northeastern Atlantic and Nordic Seas from June to August 2012. One cruise was part of the UK Ocean Acidification research programme, and the other was a repeat hydrographic transect of the Extended Ellett Line. In combination with measurements made of other variables on these and other cruises, these data can be used to constrain the anthropogenic component of dissolved inorganic carbon (DIC) in the interior ocean, and to help to determine the influence of biological carbon uptake on surface ocean carbonate chemistry. The measurements have been processed, quality-controlled and submitted to an in-preparation global compilation of seawater δ13CDIC data, and are available from the British Oceanographic Data Centre. The observed δ13CDIC values fall in a range from −0.58 to +2.37 ‰, relative to the Vienna Pee Dee Belemnite standard. The mean of the absolute differences between samples collected in duplicate in the same container type during both cruises and measured consecutively is 0.10 ‰, which corresponds to a 1σ uncertainty of 0.09 ‰, and which is within the range reported by other published studies of this kind. A crossover analysis was performed with nearby historical δ13CDIC data, indicating that any systematic offsets between our measurements and previously published results are negligible. Data doi:10.5285/09760a3a-c2b5-250b-e053-6c86abc037c0 (northeastern Atlantic), doi:10.5285/09511dd0-51db-0e21-e053-6c86abc09b95 (Nordic Seas).

scholarly journals An Internally Consistent Dataset of δ<sup>13</sup>C-DIC in the North Atlantic Ocean – NAC13v1

2016 ◽  
Author(s):  
Meike Becker ◽  
Nils Andersen ◽  
Helmut Erlenkeuser ◽  
Matthew. P. Humphreys ◽  
Toste Tanhua ◽  
...  
Keyword(s):  
Quality Control ◽  
North Atlantic ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Stable Carbon Isotope ◽  
The North ◽  
Crossover Analysis ◽  
Control Step ◽  
The North Atlantic ◽  
Quality Control Step

Abstract. The stable carbon isotope composition of dissolved inorganic carbon (δ13C-DIC) can be used to quantify fluxes within the carbon system. For example, knowing the δ13C-DIC signature of the inorganic carbon pool can help to describe the exchange between ocean and atmosphere as well as the amount of anthropogenic carbon in the water column. The measurements can also be used for evaluating modeled carbon fluxes, for making basin wide estimates, studying seasonal and interannual variability or decadal trends in interior ocean biogeochemistry. For all these purposes, it is not only important to have a sufficient amount of data, but these data must also be internally consistent and of high quality. In this study, we present a δ13C-DIC dataset for the North Atlantic, which has undergone secondary quality control. The data originate from oceanographic research cruises between 1981 and 2012. During a primary quality control step based on simple range tests obviously bad data were flagged. In a second quality control step, biases between measurements from different cruises were quantified through a crossover analysis using nearby data of the respective cruises and absolute values of biased cruises were adjusted in the data product. the crossover analysis was possible for 22 of the 29 cruises in our dataset and adjustments were applied to 10 of these. The internal accuracy of this dataset is 0.017 ‰. The dataset is available via CDIAC at http://cdiac.ornl.gov/oceans/ndp_096/NAC13v1.html, doi:10.3334/CDIAC/OTG.NAC13v1.

scholarly journals Measurements of the stable carbon isotope composition of dissolved inorganic carbon in the Northeastern Atlantic and Nordic Seas during summer 2012

2015 ◽  
Vol 8 (1) ◽  
pp. 57-82 ◽  
Author(s):  
M. P. Humphreys ◽  
E. P. Achterberg ◽  
A. M. Griffiths ◽  
A. McDonald ◽  
A. J. Boyce
Keyword(s):  
Carbon Isotope ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Isotope Composition ◽  
Stable Carbon Isotope ◽  
Carbon Isotope Composition ◽  
Stable Carbon ◽  
Nordic Seas ◽  
Stable Carbon Isotope Composition ◽  
Northeastern Atlantic

Abstract. The stable carbon isotope composition of dissolved inorganic carbon (δ13CDIC) in seawater was measured in samples collected during two cruises in the Northeastern Atlantic and Nordic Seas from June to August 2012. One cruise was part of the UK Ocean Acidification research programme, and the other was a repeat hydrographic transect of the Extended Ellett Line. In combination with measurements made of various other variables on these and other cruises, these data can be used to constrain the anthropogenic component of DIC in the interior ocean, and also assist in determining the influence of biological carbon uptake on surface ocean carbonate chemistry. The measurements have been processed, quality-controlled and submitted to an in-preparation global compilation of seawater δ13CDIC data, and are available from the British Oceanographic Data Centre. The observed δ13CDIC values fall in a range from −0.58 to +2.37‰, relative to the Vienna Peedee Belemnite standard. From duplicate samples collected during both cruises, the precision for the 552 results is 0.07‰, which is similar to other published studies of this kind. Data doi:10.5285/09760a3a-c2b5-250b-e053-6c86abc037c0 (Northeastern Atlantic), doi:10.5285/09511dd0-51db-0e21-e053-6c86abc09b95 (Nordic Seas).

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