scholarly journals Inorganic Carbon Accumulation by Chlamydomonas reinhardtii

1988 ◽  
Vol 88 (2) ◽  
pp. 491-496 ◽  
Author(s):  
Livingston J. Manuel ◽  
James V. Moroney
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Inorganic Carbon ◽  
Carbon Accumulation

scholarly journals Acclimation of Photosynthetic Light Reactions during Induction of Inorganic Carbon Accumulation in the Green Alga Chlamydomonas reinhardtii

1990 ◽  
Vol 94 (1) ◽  
pp. 357-366 ◽  
Author(s):  
Kristin Palmqvist ◽  
Lars-Göran Sundblad ◽  
Gunnar Wingsle ◽  
Göran Samuelsson
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Green Alga ◽  
Inorganic Carbon ◽  
Carbon Accumulation

Relief and calcium from gypsum as key factors for net inorganic carbon accumulation in soils of a semiarid Mediterranean environment

Geoderma ◽  
2021 ◽  
Vol 398 ◽  
pp. 115115
Author(s):  
Vito Armando Laudicina ◽  
Carmelo Dazzi ◽  
Antonio Delgado ◽  
Haydn Barros ◽  
Riccardo Scalenghe
Keyword(s):  
Inorganic Carbon ◽  
Carbon Accumulation ◽  
Mediterranean Environment ◽  
Key Factors

scholarly journals pH determines the energetic efficiency of the cyanobacterial CO2 concentrating mechanism

2016 ◽  
Vol 113 (36) ◽  
pp. E5354-E5362 ◽  
Author(s):  
Niall M. Mangan ◽  
Avi Flamholz ◽  
Rachel D. Hood ◽  
Ron Milo ◽  
David F. Savage
Keyword(s):  
Intracellular Ph ◽  
Inorganic Carbon ◽  
Quantitative Description ◽  
Carbon Accumulation ◽  
Energetic Efficiency ◽  
Ribulose Bisphosphate Carboxylase ◽  
Competitive Reaction ◽  
Bisphosphate Carboxylase ◽  
Concentrating Mechanism ◽  
Ribulose Bisphosphate Carboxylase Oxygenase

Many carbon-fixing bacteria rely on a CO2 concentrating mechanism (CCM) to elevate the CO2 concentration around the carboxylating enzyme ribulose bisphosphate carboxylase/oxygenase (RuBisCO). The CCM is postulated to simultaneously enhance the rate of carboxylation and minimize oxygenation, a competitive reaction with O2 also catalyzed by RuBisCO. To achieve this effect, the CCM combines two features: active transport of inorganic carbon into the cell and colocalization of carbonic anhydrase and RuBisCO inside proteinaceous microcompartments called carboxysomes. Understanding the significance of the various CCM components requires reconciling biochemical intuition with a quantitative description of the system. To this end, we have developed a mathematical model of the CCM to analyze its energetic costs and the inherent intertwining of physiology and pH. We find that intracellular pH greatly affects the cost of inorganic carbon accumulation. At low pH the inorganic carbon pool contains more of the highly cell-permeable H2CO3, necessitating a substantial expenditure of energy on transport to maintain internal inorganic carbon levels. An intracellular pH ≈8 reduces leakage, making the CCM significantly more energetically efficient. This pH prediction coincides well with our measurement of intracellular pH in a model cyanobacterium. We also demonstrate that CO2 retention in the carboxysome is necessary, whereas selective uptake of HCO3− into the carboxysome would not appreciably enhance energetic efficiency. Altogether, integration of pH produces a model that is quantitatively consistent with cyanobacterial physiology, emphasizing that pH cannot be neglected when describing biological systems interacting with inorganic carbon pools.

Identification and characterisation of a novel inorganic carbon acquisition gene, CIA7, from an insertional mutant of Chlamydomonas reinhardtii

2008 ◽  
Vol 35 (5) ◽  
pp. 373 ◽  
Author(s):  
Ruby A. Ynalvez ◽  
James V. Moroney
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Metal Ion ◽  
Inorganic Carbon ◽  
Antibiotic Resistance Gene ◽  
Inverse Pcr ◽  
Chloroplast Targeting ◽  
Calculated Molecular Mass ◽  
Prediction Program ◽  
Metal Transporter ◽  
Low Co2

Chlamydomonas reinhardtii is a unicellular eukaryotic alga which possesses a CO2-concentrating mechanism (CCM) that enables it to grow at low CO2 concentrations. Previously, insertional mutants were generated to enable isolation of inorganic carbon transporters and other proteins that might be essential for a functional CCM. These mutants have an antibiotic resistance gene that encodes a protein that binds to Zeocin inhibiting Zeocin’s DNA strand cleavage activity. The DNA flanking the BleR insert of one of the high CO2 requiring strains, named cia7, was cloned with inverse-PCR and sequenced. Sequence analysis showed homology to conserved bacterial proteins of unknown function, but there were no ESTs in this region of the genome. However, the presence of a gene was established by PCR and RLM-RACE. CIA7 was found to have four exons and the BleR insert was in the fourth exon. CIA7 encodes a protein of 104 amino acids with a calculated molecular mass of 11.3 kDa. Based on the ChloroP prediction program, the protein is predicted to have a chloroplast targeting signal. Complementation analyses results showed possible partially rescued mutants, and RNAi showed several transformants with a sick on low CO2 phenotype with reduced expression of CIA7. These results suggest that CIA7 is a gene that facilitates growth in C. reinhardtii under low CO2 conditions. One possible role of CIA7 would be in the delivery or storage of a metal ion. It may play a potential role as either a domain of a metal transporter or as a metallochaperone.

scholarly journals Condensation of Rubisco into a proto-pyrenoid in higher plant chloroplasts

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Nicky Atkinson ◽  
Yuwei Mao ◽  
Kher Xing Chan ◽  
Alistair J. McCormick
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Recent Work ◽  
Single Phase ◽  
Inorganic Carbon ◽  
Higher Plants ◽  
Initial Step ◽  
Operating Efficiency ◽  
Higher Plant ◽  
Spontaneous Condensation ◽  
Concentrating Mechanism

AbstractPhotosynthetic CO2 fixation in plants is limited by the inefficiency of the CO2-assimilating enzyme Rubisco. In most eukaryotic algae, Rubisco aggregates within a microcompartment known as the pyrenoid, in association with a CO2-concentrating mechanism that improves photosynthetic operating efficiency under conditions of low inorganic carbon. Recent work has shown that the pyrenoid matrix is a phase-separated, liquid-like condensate. In the alga Chlamydomonas reinhardtii, condensation is mediated by two components: Rubisco and the linker protein EPYC1 (Essential Pyrenoid Component 1). Here, we show that expression of mature EPYC1 and a plant-algal hybrid Rubisco leads to spontaneous condensation of Rubisco into a single phase-separated compartment in Arabidopsis chloroplasts, with liquid-like properties similar to a pyrenoid matrix. This work represents a significant initial step towards enhancing photosynthesis in higher plants by introducing an algal CO2-concentrating mechanism, which is predicted to significantly increase the efficiency of photosynthetic CO2 uptake.

scholarly journals Inorganic Carbon Uptake by Chlamydomonas reinhardtii

1985 ◽  
Vol 77 (2) ◽  
pp. 253-258 ◽  
Author(s):  
James V. Moroney ◽  
N. Edward Tolbert
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Inorganic Carbon ◽  
Carbon Uptake ◽  
Inorganic Carbon Uptake

The role of the chloroplast in inorganic carbon acquisition by Chlamydomonas reinhardtii

1991 ◽  
Vol 69 (5) ◽  
pp. 1017-1024 ◽  
Author(s):  
James V. Moroney ◽  
Catherine B. Mason
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Inorganic Carbon ◽  
Published Data ◽  
Carbon Uptake ◽  
Intact Chloroplasts ◽  
Inorganic Carbon Transport ◽  
Inorganic Carbon Uptake ◽  
Carbon Transport ◽  
Inorganic Carbon Acquisition

The role of the chloroplast in algal inorganic carbon acquisition is reviewed. Unicellular green algae possess the ability to grow photoautotrophically at very low CO2 concentrations. The presence of a CO2-concentrating system that elevates the CO2 level within the cell can account for the algae's ability to reduce photorespiration and grow under these conditions. The mechanism of this inorganic carbon transport is unclear at present, although both the plasmalemma and the chloroplast have been implicated in this process. Three aspects of the role of the chloroplast in Chlamydomonas reinhardtii inorganic carbon uptake are discussed in this review. First, the present models of inorganic carbon uptake are summarized. Second, the purity and integrity of intact chloroplast preparations are discussed. Third, an evaluation of the published data on inorganic carbon uptake by isolated intact chloroplasts is presented. Key words: Chlamydomonas reinhardtii, carbonic anhydrase, chloroplast, active CO2 uptake.

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