Photosynthesis in estuarine intertidal microphytobenthos is limited by inorganic carbon availability

The presence of different carbonic anhydrase (EC 4.2.1.1) activities has been investigated in the intertidal macroalgae Gracilaria sp. and Enteromorpha intestinalis (L.) Nees by using fractionation techniques. Activities, measured potentiometrically, were recorded for all fractions in both species, including those containing proteins associated with chloroplast membranes. In Gracilaria sp., most of the total activity was present in the soluble fraction, while similar activities were obtained for all fractions in E. intestinalis. By using inhibitors with a different capacity to enter the cell (acetazolamide and 6-ethoxyzolamide, inhibitors of external and total activity, respectively), a surface-accessible location was indicated for a high proportion of the soluble activity obtained in Gracilaria sp. In E. intestinalis, the inhibitor assays showed a substantial dependence of photosynthesis on intracellular activity. The short-term regulation of the extracellular activity in response to inorganic carbon availability was also examined in both macroalgae. Rapid repression (after 2 h) of the activity was recorded when Gracilaria sp. was transferred from limited to replete carbon conditions, while a fairly constant activity was recorded for E. intestinalis. In contrast, an increase of external activity was obtained for both macroalgae after being transferred to carbon-limited conditions, this response being more pronounced in E. intestinalis. Our results suggest the occurrence of a species-specific carbonic anhydrase system.

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Acclimation of photosynthetic pigments and photosynthesis of the cyanobacterium Nostoc sp. strain UAM206 to combined fluctuations of irradiance, pH, and inorganic carbon availability

Journal of Plant Physiology ◽

10.1078/0176-1617-00555 ◽

2001 ◽

Vol 158 (11) ◽

pp. 1455-1461 ◽

Cited By ~ 30

Author(s):

César Poza-Carrión ◽

Eduardo Fernández-Valiente ◽

Francisca Fernández Piñas ◽

Francisco Leganés

Keyword(s):

Photosynthetic Pigments ◽

Inorganic Carbon ◽

Carbon Availability

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Growth and photosynthetic acclimation by Ranunculus aquatilis L. in response to inorganic carbon availability

New Phytologist ◽

10.1111/j.1469-8137.1993.tb03919.x ◽

1993 ◽

Vol 125 (4) ◽

pp. 707-715 ◽

Cited By ~ 24

Author(s):

TOM VINDAEK MADSEN

Keyword(s):

Inorganic Carbon ◽

Photosynthetic Acclimation ◽

Carbon Availability

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Growth limitation of three Arctic sea ice algal species: effects of salinity, pH, and inorganic carbon availability

Polar Biology ◽

10.1007/s00300-011-0976-3 ◽

2011 ◽

Vol 34 (8) ◽

pp. 1157-1165 ◽

Cited By ~ 19

Author(s):

Dorte Haubjerg Søgaard ◽

Per Juel Hansen ◽

Søren Rysgaard ◽

Ronnie Nøhr Glud

Keyword(s):

Sea Ice ◽

Inorganic Carbon ◽

Algal Species ◽

Arctic Sea Ice ◽

Growth Limitation ◽

Carbon Availability ◽

Species Effects ◽

Arctic Sea

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Vanishing coccolith vital effects with alleviated CO<sub>2</sub> limitation

Biogeosciences Discussions ◽

10.5194/bgd-12-15835-2015 ◽

2015 ◽

Vol 12 (18) ◽

pp. 15835-15866 ◽

Cited By ~ 1

Author(s):

M. Hermoso ◽

I. Z. X. Chan ◽

H. L. O. McClelland ◽

A. M. C. Heureux ◽

R. E. M. Rickaby

Keyword(s):

Inorganic Carbon ◽

Dissolved Inorganic Carbon ◽

Calcareous Nannofossils ◽

Carbon And Oxygen Isotopes ◽

Carbon Availability ◽

Vital Effect ◽

Vital Effects ◽

Multiple Species ◽

Atmospheric Co2 Concentrations

Abstract. By recreating a range of geologically relevant concentrations of dissolved inorganic carbon (DIC) in the laboratory, we demonstrate that the magnitude of the vital effects in both carbon and oxygen isotopes of coccolith calcite of multiple species relates to ambient DIC concentration. Under high DIC levels, all the examined coccoliths lacked any offset from inorganic calcite, whereas in low (present-day) DIC concentrations, these vital effects and interspecies differences become substantial. These laboratory observations support the recent hypothesis from field observations that the appearance of interspecific vital effect in coccolithophores coincides with the long-term Neogene decline of atmospheric CO2 concentrations. The present study brings further valuable constraints on coccolith isotopic compositions by demonstrating the threshold for the absence of vital effects under high DIC regimes. From a mechanistic viewpoint, we show that the vital effect is determined by physiology; growth rate, cell size and relative rates of photosynthesis and calcification, and a modulation of these parameters with ambient carbon availability. This study provides palaeoceanographers with a biogeochemical framework that can be utilised to further develop the use of calcareous nannofossils in palaeoceanography to derive sea surface temperature and pCO2 levels.

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Coral Productivity Is Co-Limited by Bicarbonate and Ammonium Availability

Microorganisms ◽

10.3390/microorganisms8050640 ◽

2020 ◽

Vol 8 (5) ◽

pp. 640 ◽

Cited By ~ 2

Author(s):

Stephane Roberty ◽

Eric Béraud ◽

Renaud Grover ◽

Christine Ferrier-Pagès

Keyword(s):

Inorganic Carbon ◽

Dissolved Inorganic Carbon ◽

Physiological State ◽

Stylophora Pistillata ◽

Carbon Availability ◽

Carbon And Nitrogen ◽

Positive Effects ◽

Coral Holobiont ◽

Photosynthetic Performances ◽

The Impact

The nitrogen environment and nitrogen status of reef-building coral endosymbionts is one of the important factors determining the optimal assimilation of phototrophic carbon and hence the growth of the holobiont. However, the impact of inorganic nutrient availability on the photosynthesis and physiological state of the coral holobiont is partly understood. This study aimed to determine if photosynthesis of the endosymbionts associated with the coral Stylophora pistillata and the overall growth of the holobiont were limited by the availability of dissolved inorganic carbon and nitrogen in seawater. For this purpose, colonies were incubated in absence or presence of 4 µM ammonium and/or 6 mM bicarbonate. Photosynthetic performances, pigments content, endosymbionts density and growth rate of the coral colonies were monitored for 3 weeks. Positive effects were observed on coral physiology with the supplementation of one or the other nutrient, but the most important changes were observed when both nutrients were provided. The increased availability of DIC and NH4+ significantly improved the photosynthetic efficiency and capacity of endosymbionts, in turn enhancing the host calcification rate. Overall, these results suggest that in hospite symbionts are co-limited by nitrogen and carbon availability for an optimal photosynthesis.

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