The role of external carbonic anhydrase in photosynthesis during growth of the marine diatom Chaetoceros muelleri
Tamsyne Smith-Harding, John Beardall, James Mitchell
Carbon dioxide concentrating mechanisms (CCMs) act to improve the supply of CO2 at the active site of ribulose-1,5-bisphosphate carboxylase/oxygenase. There is substantial evidence that in some microalgal species CCMs involve an external carbonic anhydrase (CAext) and that CAext activity is induced by low CO2 concentrations in the growth medium. However, much of this work has been conducted on cells adapted to air-equilibrium concentrations of CO2, rather than to changing CO2 conditions caused by growing microalgal populations. We investigated the role of CAext in inorganic carbon (Ci) acquisition and photosynthesis at three sampling points during the growth cycle of the cosmopolitan marine diatom Chaetoceros muelleri. We observed that CAext activity increased with decreasing Ci, particularly CO2, concentration, supporting the idea that CAext is modulated by external CO2 concentration. Additionally, we found that the contribution of CAext activity to carbon acquisition for photosynthesis varies over time, increasing between the first and second sampling points before decreasing at the last sampling point, where external pH was high. Lastly, decreases in maximum quantum yield of photosystem II (Fv/Fm), chlorophyll, maximum relative electron transport rate, light harvesting efficiency (α) and maximum rates of Ci- saturated photosynthesis (Vmax) were observed over time. Despite this decrease in photosynthetic capacity an up-regulation of CCM activity, indicated by a decreasing half-saturation constant for CO2 (K0.5CO2), occurred over time. The flexibility of the CCM during the course of growth in C. muelleri may contribute to the reported dominance and persistence of this species in phytoplankton blooms.
JOURNAL OF PHYCOLOGY
https://doi.org/10.1111/jpy.12572
10.1111/jpy.12572
Fingerprint Dive into the research topics of 'The role of external carbonic anhydrase in photosynthesis during growth of the marine diatom Chaetoceros muelleri'. Together they form a unique fingerprint.
Chaetoceros muelleri Agriculture & Biology
carbonate dehydratase Agriculture & Biology
Bacillariophyceae Agriculture & Biology
carbon dioxide Agriculture & Biology
photosynthesis Agriculture & Biology
concentrating Agriculture & Biology
inorganic carbon Agriculture & Biology
algal blooms Agriculture & Biology
Smith-Harding, T., Beardall, J., & Mitchell, J. (2017). The role of external carbonic anhydrase in photosynthesis during growth of the marine diatom Chaetoceros muelleri. JOURNAL OF PHYCOLOGY, 53(6), 1159-1170. https://doi.org/10.1111/jpy.12572
Smith-Harding, Tamsyne ; Beardall, John ; Mitchell, James. / The role of external carbonic anhydrase in photosynthesis during growth of the marine diatom Chaetoceros muelleri. In: JOURNAL OF PHYCOLOGY. 2017 ; Vol. 53, No. 6. pp. 1159-1170.
@article{346ad4e4c969432ab6630fb20a2ac82d,
title = "The role of external carbonic anhydrase in photosynthesis during growth of the marine diatom Chaetoceros muelleri",
abstract = "Carbon dioxide concentrating mechanisms (CCMs) act to improve the supply of CO2 at the active site of ribulose-1,5-bisphosphate carboxylase/oxygenase. There is substantial evidence that in some microalgal species CCMs involve an external carbonic anhydrase (CAext) and that CAext activity is induced by low CO2 concentrations in the growth medium. However, much of this work has been conducted on cells adapted to air-equilibrium concentrations of CO2, rather than to changing CO2 conditions caused by growing microalgal populations. We investigated the role of CAext in inorganic carbon (Ci) acquisition and photosynthesis at three sampling points during the growth cycle of the cosmopolitan marine diatom Chaetoceros muelleri. We observed that CAext activity increased with decreasing Ci, particularly CO2, concentration, supporting the idea that CAext is modulated by external CO2 concentration. Additionally, we found that the contribution of CAext activity to carbon acquisition for photosynthesis varies over time, increasing between the first and second sampling points before decreasing at the last sampling point, where external pH was high. Lastly, decreases in maximum quantum yield of photosystem II (Fv/Fm), chlorophyll, maximum relative electron transport rate, light harvesting efficiency (α) and maximum rates of Ci- saturated photosynthesis (Vmax) were observed over time. Despite this decrease in photosynthetic capacity an up-regulation of CCM activity, indicated by a decreasing half-saturation constant for CO2 (K0.5CO2), occurred over time. The flexibility of the CCM during the course of growth in C. muelleri may contribute to the reported dominance and persistence of this species in phytoplankton blooms.",
author = "Tamsyne Smith-Harding and John Beardall and James Mitchell",
doi = "10.1111/jpy.12572",
journal = "JOURNAL OF PHYCOLOGY",
Smith-Harding, T, Beardall, J & Mitchell, J 2017, 'The role of external carbonic anhydrase in photosynthesis during growth of the marine diatom Chaetoceros muelleri', JOURNAL OF PHYCOLOGY, vol. 53, no. 6, pp. 1159-1170. https://doi.org/10.1111/jpy.12572
The role of external carbonic anhydrase in photosynthesis during growth of the marine diatom Chaetoceros muelleri. / Smith-Harding, Tamsyne; Beardall, John; Mitchell, James.
In: JOURNAL OF PHYCOLOGY, Vol. 53, No. 6, 2017, p. 1159-1170.
T1 - The role of external carbonic anhydrase in photosynthesis during growth of the marine diatom Chaetoceros muelleri
AU - Smith-Harding, Tamsyne
AU - Beardall, John
AU - Mitchell, James
N2 - Carbon dioxide concentrating mechanisms (CCMs) act to improve the supply of CO2 at the active site of ribulose-1,5-bisphosphate carboxylase/oxygenase. There is substantial evidence that in some microalgal species CCMs involve an external carbonic anhydrase (CAext) and that CAext activity is induced by low CO2 concentrations in the growth medium. However, much of this work has been conducted on cells adapted to air-equilibrium concentrations of CO2, rather than to changing CO2 conditions caused by growing microalgal populations. We investigated the role of CAext in inorganic carbon (Ci) acquisition and photosynthesis at three sampling points during the growth cycle of the cosmopolitan marine diatom Chaetoceros muelleri. We observed that CAext activity increased with decreasing Ci, particularly CO2, concentration, supporting the idea that CAext is modulated by external CO2 concentration. Additionally, we found that the contribution of CAext activity to carbon acquisition for photosynthesis varies over time, increasing between the first and second sampling points before decreasing at the last sampling point, where external pH was high. Lastly, decreases in maximum quantum yield of photosystem II (Fv/Fm), chlorophyll, maximum relative electron transport rate, light harvesting efficiency (α) and maximum rates of Ci- saturated photosynthesis (Vmax) were observed over time. Despite this decrease in photosynthetic capacity an up-regulation of CCM activity, indicated by a decreasing half-saturation constant for CO2 (K0.5CO2), occurred over time. The flexibility of the CCM during the course of growth in C. muelleri may contribute to the reported dominance and persistence of this species in phytoplankton blooms.
AB - Carbon dioxide concentrating mechanisms (CCMs) act to improve the supply of CO2 at the active site of ribulose-1,5-bisphosphate carboxylase/oxygenase. There is substantial evidence that in some microalgal species CCMs involve an external carbonic anhydrase (CAext) and that CAext activity is induced by low CO2 concentrations in the growth medium. However, much of this work has been conducted on cells adapted to air-equilibrium concentrations of CO2, rather than to changing CO2 conditions caused by growing microalgal populations. We investigated the role of CAext in inorganic carbon (Ci) acquisition and photosynthesis at three sampling points during the growth cycle of the cosmopolitan marine diatom Chaetoceros muelleri. We observed that CAext activity increased with decreasing Ci, particularly CO2, concentration, supporting the idea that CAext is modulated by external CO2 concentration. Additionally, we found that the contribution of CAext activity to carbon acquisition for photosynthesis varies over time, increasing between the first and second sampling points before decreasing at the last sampling point, where external pH was high. Lastly, decreases in maximum quantum yield of photosystem II (Fv/Fm), chlorophyll, maximum relative electron transport rate, light harvesting efficiency (α) and maximum rates of Ci- saturated photosynthesis (Vmax) were observed over time. Despite this decrease in photosynthetic capacity an up-regulation of CCM activity, indicated by a decreasing half-saturation constant for CO2 (K0.5CO2), occurred over time. The flexibility of the CCM during the course of growth in C. muelleri may contribute to the reported dominance and persistence of this species in phytoplankton blooms.
U2 - 10.1111/jpy.12572
DO - 10.1111/jpy.12572
JO - JOURNAL OF PHYCOLOGY
JF - JOURNAL OF PHYCOLOGY
Smith-Harding T, Beardall J, Mitchell J. The role of external carbonic anhydrase in photosynthesis during growth of the marine diatom Chaetoceros muelleri. JOURNAL OF PHYCOLOGY. 2017;53(6):1159-1170. https://doi.org/10.1111/jpy.12572