Carbon isotopic fractionation by plankton in the Southern Indian Ocean: relationship between δ of particulate organic carbon and dissolved carbon dioxide

Bentaleb, I.; Fontugne, Michel; Descolas-Gros, C.; Girardin, Cyril; Mariotti, André; Cartigny, Pierre; Brunet, Christian; Poisson, Alain

doi:10.1016/s0924-7963(98)00028-1

Cited by 85 publications

(46 citation statements)

References 56 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Moreover, the measured b carboxylase activities may have been confounded by the presence of mixotrophic and heterotrophic organisms, and it is possible that the decrease in PEPC activity in low-CO 2 , high-chlorophyll waters (Fig. 3) reflected a lower relative abundance of mixotrophs as previously suggested (Bentaleb et al 1998). At present, the available field data suggest that PEPC can make a significant contribution to C fixation by marine plankton assemblages, although the exact biochemical role of this enzyme remains unclear.…”

Section: Discussionmentioning

confidence: 65%

Inorganic carbon uptake and intracellular assimilation by subarctic Pacific phytoplankton assemblages

2006

View full text Add to dashboard Cite

We report the results of inorganic carbon (C) uptake experiments and activity measurements for carbonic anhydrase, ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco), and phosphoenolpyruvate carboxylase (PEPC) in offshore and coastal regions of the eastern subarctic Pacific Ocean. HCO 2 3 was the dominant source of inorganic C taken up by phytoplankton at all sampling locations, accounting for ,60-90% of total C uptake. The uptake of HCO 2 3 occurred primarily through a direct transport system, while indirect HCO 2 3 use, mediated by extracellular carbonic anhydrase (eCA), played a minor role in the C uptake system. Direct HCO 2 3 transport and eCA activity were not related to ambient nutrient or CO 2 concentrations or to phytoplankton biomass (chlorophyll a [Chl a]) or primary productivity. There was significant variability in the biomass-normalized activities of Rubisco, PEPC, and total (intracellular and extracellular) carbonic anhydrase. The activities of all of the enzymes measured exhibited significant correlations with both CO 2 concentrations and Chl a. PEPC activity averaged 20% of Rubisco activity (range 0.5-110%), and the PEPC : Rubisco ratio was positively correlated with CO 2 concentrations and negatively correlated with Chl a. Carbonic anhydrase activity was strongly anticorrelated with CO 2 and positively correlated with Chl a. The results provide evidence for the importance of CO 2 -regulated carbon concentrating mechanisms in marine waters.Laboratory studies have documented the existence of inorganic carbon concentrating mechanisms (CCMs) in a variety of marine algal and cyanobacterial species (see Kaplan andReinhold 1999, andColman et al. 2002 for recent reviews). Although the molecular pathways have not been fully resolved, it is clear that CCMs enable cells to saturate carbon (C) fixation by ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) despite the poor catalytic efficiency of this enzyme (Spreitzer and Salvucci 2002) and the relatively low CO 2 concentrations in seawater. The CCM consists of a high affinity uptake system for inorganic C and the intracellular accumulation of CO 2 in the vicinity of Rubisco. Many phytoplankton species appear to use the abundant HCO 2 3 ion as a C source, through either a direct transport system or an indirect uptake pathway in which carbonic anhydrase (CA) catalyzes the otherwise slow dehydration of HCO 2 3 to CO 2 in the cell boundary layer (Sü ltemeyer et al. 1993;Badger 2004). Recent evidence also suggests that some phytoplankton species may possess a C 4 photosynthetic pathway in which intracellular HCO 2 3 is converted to an organic acid via phosphoenolpyruvate carboxylase (PEPC), and CO 2 is subsequently liberated by decarboxylation in close proximity to Rubisco (Reinfelder et al. 2000). By regulating the activity of the C transport system, Rubisco, carbonic anhydrase, and potentially PEPC, phytoplankton species may optimize growth over a wide range of ambient CO 2 concentrations.While laboratory experiments have provided detai...

show abstract

Section: Discussionmentioning

confidence: 65%

Inorganic carbon uptake and intracellular assimilation by subarctic Pacific phytoplankton assemblages

2006

View full text Add to dashboard Cite

show abstract

“…and the phytoplankton community (autotrophs and mixotrophs), while heterotrophs prefer assimilation of dissolved organic carbon over inorganic carbon [CO 2(aq) ] (Hayes, 1993;Bentaleb et al, 1998). On the other hand, δ 15 N (POM) is used to study processes involved in cycling of organic matter, specially nitrogen related processes like nitrate uptake, nitrification, denitrification, remineralisation, etc.…”

Section: Introductionmentioning

confidence: 99%

Latitudinal δ13C and δ15N variations in particulate organic matter (POM) in surface waters from the Indian ocean sector of Southern Ocean and the Tropical Indian Ocean in 2012

Soares

Bhaskar

Naik

et al. 2015

Deep Sea Research Part II: Topical Studies in Oceanography

View full text Add to dashboard Cite

“…C with increasing latitude has been mainly attributed to changes in the concentration of aqueous CO 2 (Rau et al 1989, Bentaleb et al 1998). These regional and latitudinal δ 13 C gradients have been also used as an effective way for investigating seasonal change in the foraging areas of marine predators ).…”

mentioning

confidence: 99%

Foraging ecology of Mediterranean fin whales in a changing environment elucidated by satellite tracking and baleen plate stable isotopes

Bentaleb¹,

Martin²,

Vrac³

et al. 2011

Mar. Ecol. Prog. Ser.

101

View full text Add to dashboard Cite

We investigated seasonal shifts in diet and distribution of fin whales Bala en optera physalus occurring in the western Mediterranean Sea. For this purpose, we combined carbon and nitrogen stable isotope ratios (δ This pattern was confirmed by satellite tracking; 1 out of 8 fin whales we successfully tracked left the Mediterranean for the Atlantic. Longer-term changes in isotopic signatures of baleen plates exhibited significant depletion trends, indicating that changes due to increasing input of nutrients and anthropogenic carbon are occurring in the western Mediterranean Sea ecosystem.

show abstract

Carbon isotopic fractionation by plankton in the Southern Indian Ocean: relationship between δ of particulate organic carbon and dissolved carbon dioxide

Cited by 85 publications

References 56 publications

Inorganic carbon uptake and intracellular assimilation by subarctic Pacific phytoplankton assemblages

Inorganic carbon uptake and intracellular assimilation by subarctic Pacific phytoplankton assemblages

Latitudinal δ13C and δ15N variations in particulate organic matter (POM) in surface waters from the Indian ocean sector of Southern Ocean and the Tropical Indian Ocean in 2012

Foraging ecology of Mediterranean fin whales in a changing environment elucidated by satellite tracking and baleen plate stable isotopes

Contact Info

Product

Resources

About

Carbon isotopic fractionation by plankton in the Southern Indian Ocean: relationship between δ of particulate organic carbon and dissolved carbon dioxide

Cited by 85 publications

References 56 publications

Inorganic carbon uptake and intracellular assimilation by subarctic Pacific phytoplankton assemblages

Inorganic carbon uptake and intracellular assimilation by subarctic Pacific phytoplankton assemblages

Latitudinal δ13C and δ15N variations in particulate organic matter (POM) in surface waters from the Indian ocean sector of Southern Ocean and the Tropical Indian Ocean in 2012

Foraging ecology of Mediterranean fin whales in a changing environment elucidated by satellite ­tracking and baleen plate stable isotopes

Contact Info

Product

Resources

About

Foraging ecology of Mediterranean fin whales in a changing environment elucidated by satellite tracking and baleen plate stable isotopes