CO<sub>2</sub> CONCENTRATING MECHANISMS IN PHOTOSYNTHETIC MICROORGANISMS

Kaplan, Aaron; Reinhold, Leonora

doi:10.1146/annurev.arplant.50.1.539

Cited by 649 publications

(616 citation statements)

References 145 publications

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“…Although total inorganic carbon and CO2 concentration are considered the most important factors inducing CA activity (10,17), alkalization of the growing media also plays an important role. One of the consequences of this alkalization, caused mainly by the photosynthetic process (3) and nitrate uptake (29,31) is the shift of the equilibrium of inorganic carbon species toward HCO3 -, thus lowering the CO2 concentration.…”

Section: Discussionmentioning

confidence: 99%

“…Soon after the cultures were put in the dark, the enzymatic activity begun to fall. One model that explains the activation of CA by light proposes that the photosynthetic electron transport causes the formation of alkaline pockets around CA, in the thylakoid or in the cytoplasmatic membrane and, as a consequence, the generation of HCO 3 -from CO 2 is accelerated (17,27). Sulfanilamide binds to the Zn atom in the active site of the enzyme, causing its inhibition and it is widely used in the studies with Carbonic Anhydrase.…”

Section: Discussionmentioning

confidence: 99%

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Extra and intracelular activities of carbonic anhydrase of the marine microalga Tetraselmis gracilis (Chlorophyta)

Rigobello-Masini¹,

Aidar²,

Masini³

2003

Braz. J. Microbiol.

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The activities of extra and intracellular carbonic anhydrases (CA) were studied in the microalgae Tetraselmis gracilis (Kylin) Butcher (Chlorophyta, Prasinophyceae) growing in laboratory cultivation. During ten days of batch cultivation, daily determinations of pH, cell number, enzymatic activity, and total dissolved inorganic carbon (DIC), as well as its main species, CO2 and HCO3 -, were performed. Enzymatic activity increased as the growing cell population depleted inorganic carbon from the medium. Carbon dioxide concentration decreased quickly, especially in the third day of cultivation, when a significant increase of the intracellular enzymatic activity was observed. Bicarbonate concentration had its largest decrease in the cultivation medium in the fourth day, when the activity of the extracellular enzyme had its largest increase, suggesting its use by the alga through CA activity. After the fourth cultivation day, half of the cultures were aerated with CO2-free atmospheric air, which caused an increase in the total and external activity of the enzyme, although, in this condition, the stationary growth phase began earlier than in cultures aerated with atmospheric air. The pH of the media was measured daily, increasing from the first to the fourth day, and remaining almost constant until the end of the cultivation. Algal material transferred to the dark lost all enzymatic activity.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Extra and intracelular activities of carbonic anhydrase of the marine microalga Tetraselmis gracilis (Chlorophyta)

Rigobello-Masini¹,

Aidar²,

Masini³

2003

Braz. J. Microbiol.

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“…All cyanobacterial species investigated to date, however, possess mechanisms to enhance the carboxylation efficiency of their RubisCO, reducing the risk of carbon limitation. These processes are commonly referred to as CO 2 concentrating mechanisms (CCMs; Badger et al 2006;Giordano et al 2005;Kaplan and Reinhold 1999). Although CCM functioning should significantly repress the oxygenase function of RubisCO (Colman 1989), photorespiration has recently been found to occur under certain conditions in Synechocystis PCC6803 (Eisenhut et al 2008).…”

Section: Inorganic Carbon Acquisitionmentioning

confidence: 99%

“…The energetic demand of the different C acquisition systems is, however, still under debate Photosynth Res differentiating the genera of cyanobacteria into two classes, the a-and b-cyanobacteria. Further information on the role of carboxysomes in the cyanobacterial CCM can be found in several reviews (Badger et al 2006;Cannon et al 2001;Kaplan and Reinhold 1999;Price et al 2002). All in all, a large diversity in CCMs has evolved that allows cyanobacteria to grow over a wide range of C i concentrations.…”

Section: Inorganic Carbon Acquisitionmentioning

confidence: 99%

Interactions between CCM and N2 fixation in Trichodesmium

2010

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In view of the current increase in atmospheric pCO 2 and concomitant changes in the marine environment, it is crucial to assess, understand, and predict future responses of ecologically relevant phytoplankton species. The diazotrophic cyanobacterium Trichodesmium erythraeum was found to respond strongly to elevated pCO 2 by increasing growth, production rates, and N 2 fixation. The magnitude of these CO 2 effects exceeds those previously seen in other phytoplankton, raising the question about the underlying mechanisms. Here, we review recent publications on metabolic pathways of Trichodesmium from a gene transcription level to the protein activities and energy fluxes. Diurnal patterns of nitrogenase activity change markedly with CO 2 availability, causing higher diel N 2 fixation rates under elevated pCO 2 . The observed responses to elevated pCO 2 could not be attributed to enhanced energy generation via gross photosynthesis, although there are indications for CO 2 -dependent changes in ATP/ NADPH ? H ? production. The CO 2 concentrating mechanism (CCM) in Trichodesmium is primarily based on HCO 3 -uptake. Although only little CO 2 uptake was detected, the NDH complex seems to play a crucial role in internal cycling of inorganic carbon, especially under elevated pCO 2 . Affinities for inorganic carbon change over the day, closely following the pattern in N 2 fixation, and generally decrease with increasing pCO 2 . This down-regulation of CCM activity and the simultaneously enhanced N 2 fixation point to a shift in energy allocation from carbon acquisition to N 2 fixation under elevated pCO 2 levels. A strong light modulation of CO 2 effects further corroborates the role of energy fluxes as a key to understand the responses of Trichodesmium.

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“…However, carboxysomes and the S. enterica organelles differ in a number of ways. Carboxysomes function to enhance autotrophic growth at low CO 2 concentrations (2,21,25,33), and the carboxysomes of Halothiobacillus neapolitanus (which are the best studied) consist of a protein shell composed of at …”

mentioning

confidence: 99%

Protein Content of Polyhedral Organelles Involved in Coenzyme B ₁₂ -Dependent Degradation of 1,2-Propanediol in Salmonella enterica Serovar Typhimurium LT2

2003

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Salmonella enterica forms polyhedral organelles during coenzyme B 12 -dependent growth on 1,2-propanediol (1,2-PD). Previously, these organelles were shown to consist of a protein shell partly composed of the PduA protein, the majority of the cell's B 12 -dependent diol dehydratase, and additional unidentified proteins. In this report, the polyhedral organelles involved in B 12 -dependent 1,2-PD degradation by S. enterica were purified by a combination of detergent extraction and differential and density gradient centrifugation. The course of the purification was monitored by electron microscopy and gel electrophoresis, as well as enzymatic assay of B 12 -dependent diol dehydratase. Following one-and two-dimensional gel electrophoresis of purified organelles, the identities and relative abundance of their constituent proteins were determined by N-terminal sequencing, protein mass fingerprinting, Western blotting, and densitometry. These analyses indicated that the organelles consisted of at least 15 proteins, including PduABB CDEGHJKOPTU and one unidentified protein. Seven of the proteins identified (PduABB JKTU) have some sequence similarity to the shell proteins of carboxysomes (a polyhedral organelle involved in autotrophic CO 2 fixation), suggesting that the S. enterica organelles and carboxysomes have a related multiprotein shell. In addition, S. enterica organelles contained four enzymes: B 12 -dependent diol dehydratase, its putative reactivating factor, aldehyde dehydrogenase, and ATP cob(I) alamin adenosyltransferase. This complement of enzymes indicates that the primary catalytic function of the S. enterica organelles is the conversion of 1,2-PD to propionyl coenzyme A (which is consistent with our prior proposal that the S. enterica organelles function to minimize aldehyde toxicity during growth on 1,2-PD). The possibility that similar protein-bound organelles may be more widespread in nature than currently recognized is discussed.The vitamin B 12 coenzymes adenosyl-B 12 (Ado-B 12 ) and methyl-B 12 (CH 3 -B 12 ) are required cofactors for at least 15 different enzymes (5, 27, 30). These enzymes have a broad but uneven distribution among living forms and are vital to human health, are essential to the carbon cycle, and have important industrial applications (5, 27, 30). Historically, bacteria have provided excellent model systems for the study of vitamins, and recent investigations with several bacterial systems have found the molecular biology of B 12 -dependent processes to be unexpectedly complex (9,27,29,34,35). One of the most surprising findings in this area has been the identification of a polyhedral organelle involved in coenzyme B 12 -dependent 1,2-propanediol (1,2-PD) degradation by Salmonella enterica (9).Salmonella enterica utilizes 1,2-PD as a carbon and energy source in an Ado-B 12 -dependent fashion (19). Degradation occurs aerobically, or anaerobically if tetrathionate is added as a terminal electron acceptor (26). Based on biochemical studies, a pathway for 1,2-PD degradation has been ...

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CO₂ CONCENTRATING MECHANISMS IN PHOTOSYNTHETIC MICROORGANISMS

Cited by 649 publications

References 145 publications

Extra and intracelular activities of carbonic anhydrase of the marine microalga Tetraselmis gracilis (Chlorophyta)

Extra and intracelular activities of carbonic anhydrase of the marine microalga Tetraselmis gracilis (Chlorophyta)

Interactions between CCM and N2 fixation in Trichodesmium

Protein Content of Polyhedral Organelles Involved in Coenzyme B ₁₂ -Dependent Degradation of 1,2-Propanediol in Salmonella enterica Serovar Typhimurium LT2

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CO2 CONCENTRATING MECHANISMS IN PHOTOSYNTHETIC MICROORGANISMS

Cited by 649 publications

References 145 publications

Extra and intracelular activities of carbonic anhydrase of the marine microalga Tetraselmis gracilis (Chlorophyta)

Extra and intracelular activities of carbonic anhydrase of the marine microalga Tetraselmis gracilis (Chlorophyta)

Interactions between CCM and N2 fixation in Trichodesmium

Protein Content of Polyhedral Organelles Involved in Coenzyme B 12 -Dependent Degradation of 1,2-Propanediol in Salmonella enterica Serovar Typhimurium LT2

Contact Info

Product

Resources

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CO₂ CONCENTRATING MECHANISMS IN PHOTOSYNTHETIC MICROORGANISMS

Protein Content of Polyhedral Organelles Involved in Coenzyme B ₁₂ -Dependent Degradation of 1,2-Propanediol in Salmonella enterica Serovar Typhimurium LT2