Carbonic anhydrase activity and inorganic carbon fluxes in low- and high-Ci cells of Chlamydomonas reinhardtii and Scenedesmus obliquus

Palmqvist, Kristin; Badger, Murray R.

doi:10.1034/j.1399-3054.1994.900315.x

Cited by 52 publications

(112 citation statements)

References 11 publications

Supporting

Mentioning

101

Contrasting

Order By: Relevance

“…In Trichodesmium, eCA activities were about 50 6 10 units (mg Chl a) 21 , and they neither varied between treatments nor over the photoperiod (data not shown). The activity of internal CA remained constant in all acclimations and was near the detection limit, i.e., D values were about 0.25 6 0.08 (mg Chl a) 21 following calculations of Palmqvist et al (1994).…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Carbon acquisition by Trichodesmium: the effect of pCO2 and diurnal changes

Kranz

Sültemeyer

Richter

et al. 2009

Limnology & Oceanography

124

178

View full text Add to dashboard Cite

We investigated carbon acquisition by the N 2 -fixing cyanobacterium Trichodesmium IMS101 in response to CO 2 levels of 15.1, 37.5, and 101.3 Pa (equivalent to 150, 370, and 1000 ppm). In these acclimations, growth rates as well as cellular C and N contents were measured. In vivo activities of carbonic anhydrase (CA), photosynthetic O 2 evolution, and CO 2 and HCO { 3 fluxes were measured using membrane inlet mass spectrometry and the 14 C disequilibrium technique. While no differences in growth rates were observed, elevated CO 2 levels caused higher C and N quotas and stimulated photosynthesis and N 2 fixation. Minimal extracellular CA (eCA) activity was observed, indicating a minor role in carbon acquisition. Rates of CO 2 uptake were small relative to total inorganic carbon (Ci) fixation, whereas HCO { 3 contributed more than 90% and varied only slightly over the light period and between CO 2 treatments. The low eCA activity and preference for HCO { 3 were verified by the 14 C disequilibrium technique. Regarding apparent affinities, half-saturation concentrations (K 1/2 ) for photosynthetic O 2 evolution and HCO { 3 uptake changed markedly over the day and with CO 2 concentration. Leakage (CO 2 efflux : Ci uptake) showed pronounced diurnal changes. Our findings do not support a direct CO 2 effect on the carboxylation efficiency of ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO) but point to a shift in resource allocation among photosynthesis, carbon acquisition, and N 2 fixation under elevated CO 2 levels. The observed increase in photosynthesis and N 2 fixation could have potential biogeochemical implications, as it may stimulate productivity in N-limited oligotrophic regions and thus provide a negative feedback on rising atmospheric CO 2 levels.

show abstract

Section: Resultsmentioning

confidence: 99%

“…The activity of iCA was estimated from the rapid decline in log (enrichment) upon the injection of cells, defined as D, and calculated according to Palmqvist et al (1994). Values of D are expressed per mg Chl a.…”

Section: Methodsmentioning

confidence: 99%

Carbon acquisition by Trichodesmium: the effect of pCO2 and diurnal changes

Kranz

Sültemeyer

Richter

et al. 2009

Limnology & Oceanography

124

178

View full text Add to dashboard Cite

show abstract

“…(1994). This method has been applied in several studies of cyanobacteria and freshwater microalgae (Palmqvist et al 1994;Tchernov et al 1997;Sültemeyer et al 1998) and recently also of marine phytoplankton (Burkhardt et al 2001;Rost et al 2003). Cellular leakage was estimated from the CO 2 efflux observed right after turning off the light .…”

Section: Methodsmentioning

confidence: 99%

Carbon acquisition of marine phytoplankton: Effect of photoperiod length

2006

View full text Add to dashboard Cite

We investigated the carbon acquisition of three marine microalgae, Skeletonema costatum, Phaeocystis globosa, and Emiliania huxleyi in response to different light regimes. Rates of photosynthetic O 2 evolution and CO 2 and HCO uptake were measured by membrane inlet mass spectrometry in cells acclimated to cycles of 16 : 8 light :Ϫ 3 dark (LD; h : h) and 12 : 12 LD and were compared with those obtained under continuous light. In addition, cellular leakage was estimated for different photoperiods and ambient CO 2 concentrations during growth. Maximum rates of photosynthesis more or less doubled under LD cycles compared with continuous light. In S. costatum and E. huxleyi, a remarkably higher contribution of HCO to the overall carbon uptake was observed under LD cycles. Incontrast, P. globosa did not change its CO 2 : HCO uptake ratio in response to daylength. Half saturation concen-Ϫ 3 trations (K 1/2 ) for O 2 evolution and inorganic carbon (Ci) uptake were also influenced by the photoperiod. Under LD cycles K 1/2 values for photosynthesis in S. costatum and P. globosa were similar or higher compared with continuous light, whereas they were much lower in E. huxleyi. With the exception of CO 2 uptake in E. huxleyi and P. globosa, affinities for Ci decreased under the LD cycles. Cellular leakage was highest for E. huxleyi and lowest for S. costatum and generally decreased with increasing CO 2 concentration. Although this study confirms speciesspecific differences in the CO 2 -concentrating mechanisms (CCMs), the effect of daylength on CO 2 and HCO uptake Ϫ 3 has hitherto not been described. We put forward the idea that variations in light condition influence the cellular carbon demand, thereby imposing a stronger control on CCM regulation than the naturally occurring changes in CO 2 supply.

show abstract

“…The induction and location (plasmalemma or chloroplast envelope) of the inorganic carbon transport system, are also open to debate (Rotatore & Colman, 1990 ;Palmqvist et al, 1994a). Additionally, the pyrenoid, a starch-coated structure containing Rubisco (Vaughn et al, 1992) present in the chloroplast of many microalgae and some Anthocerotae, might play a functional role, being directly analogous with the cyanobacterial carboxysome, or providing a means of separating oxygenic PSII from Rubisco.…”

Section: Measurements Of Kmentioning

confidence: 99%

“…One recent hypothesis suggests that a range of CCM characteristics might be engendered by the intrathylakoid CA, with the localised enrichment provided by subsequent CO # leakage supplying Rubisco (Raven, 1997) . Investigations of CA activity associated with microalgae which demonstrate CCM activity indicate that the activity of both periplasmic and intracellular CA increases in low-C i -grown cells and that this increase is associated with increased affinity for the uptake of both CO # and HCO $ − (Miyachi et al, 1985: Palmqvist et al, 1994a. However, the precise subcellular localization of isozymes of CA has yet to be achieved and CA isozymes of the β type have been shown to exhibit high intracellular activity in microalgae which have been shown to lack a CCM (Palmqvist et al, 1995) indicating that these enzymes are not exclusively associated with CCM activity.…”

Section: Measurements Of Kmentioning

confidence: 99%

The role of carbonic anhydrase in photosynthesis and the activity of the carbon‐concentrating‐mechanism in bryophytes of the class Anthocerotae

Smith

Griffiths

2000

New Phytologist

View full text Add to dashboard Cite

The role of carbonic anhydrase in the carbon-concentrating-mechanism of bryophytes of the class Anthocerotae was investigated by comparing the gas-exchange characteristics of material which had been incubated in the membrane-permeable Carbonic Anhydrase inhibitor ethoxyzolamide, with those of untreated material and material which had been incubated in buffer solution. In Phaeoceros laevis (Anthocerotae), incubation in ethoxyzolamide caused a depression in the rate of gross assimilation and a decrease in CO # affinity beyond that which could be attributed to increased diffusion limitation. A range of liverworts and mosses, in which a carbonconcentrating-mechanism is absent, were also investigated. These showed no depression of rates of gross assimilation after incubation in ethoxyzolamide relative to those of untreated material. The CO # compensation point and CO # uptake characteristics of Phaeoceros laevis were significantly affected by incubation in ethoxyzolamide. Values of CO # compensation point for Phaeoceros laevis rose from 2.5 Pa, after incubation in buffer, to 20 Pa after incubation in ethoxyzolamide. The CO # compensation point for the liverworts Pellia epiphylla and Marchantia polymorpha was not significantly affected by incubation in ethoxyzolamide. Measurements of the release of CO # at the end of a short (15 min) period of illumination revealed that, after suppression of carbonic anhydrase activity, the rapid release of a CO # pool occurred in Phaeoceros laevis but not in the liverworts. There were also significant differences between values for fractionation measured in units per mil (=), measured instantaneously, for Phaeoceros laevis incubated in ethoxyzolamide, compared with fractionation values for this species after incubation in buffer. Incubation in ethoxyzolamide caused fractionation values to rise from 12.4-22.7=, indicating that the carbon-concentrating-mechanism of this species had been inactivated. Incubation in ethoxyzolamide had no effect on fractionation values for the liverworts. The convexity of the light saturation curves of liverworts and Phaeoceros laevis was also investigated, but there were no differences between groups before or after the two treatments. The data indicate an important role for carbonic anhydrase in the functioning of the carbon-concentrating-mechanism in the Anthocerotae.

show abstract

Carbonic anhydrase activity and inorganic carbon fluxes in low- and high-Ci cells of Chlamydomonas reinhardtii and Scenedesmus obliquus

Cited by 52 publications

References 11 publications

Carbon acquisition by Trichodesmium: the effect of pCO2 and diurnal changes

Carbon acquisition by Trichodesmium: the effect of pCO2 and diurnal changes

Carbon acquisition of marine phytoplankton: Effect of photoperiod length

The role of carbonic anhydrase in photosynthesis and the activity of the carbon‐concentrating‐mechanism in bryophytes of the class Anthocerotae

Contact Info

Product

Resources

About