RT Journal Article
T1 Singular adaptations in the carbon assimilation mechanism of the polyextremophile cyanobacterium Chroococcidiopsis thermalis
A1 Aguiló-Nicolau, Pere
A1 Galmés, Jeroni
A1 Fais, Giacomo
A1 Capó-Bauçà, Sebastià
A1 Cao, Giacomo
A1 Íñiguez Moreno, Concepción
K1 Enzimas - Cinética
K1 Cianobacterias - Biotecnología
K1 Carbono - Fijación
AB Cyanobacteria largely contribute to the biogeochemical carbon cycle fixing ~ 25% of the inorganic carbon on Earth. However, the carbon acquisition and assimilation mechanisms in Cyanobacteria are still underexplored regardless of being of great importance for shedding light on the origins of autotropism on Earth and providing new bioengineering tools for crop yield improvement. Here, we fully characterized these mechanisms from the polyextremophile cyanobacterium Chroococcidiopsis thermalis KOMAREK 1964/111 in comparison with the model cyanobacterial strain, Synechococcus sp. PCC6301. In particular, we analyzed the Rubisco kinetics along with the in vivo photosynthetic CO2 assimilation in response to external dissolved inorganic carbon, the effect of CO2 concentrating mechanism (CCM) inhibitors on net photosynthesis and the anatomical particularities of their carboxysomes when grown under either ambient air (0.04% CO2) or 2.5% CO2-enriched air. Our results show that Rubisco from C. thermalis possess the highest specificity factor and carboxylation efficiency ever reported for Cyanobacteria, which were accompanied by a highly effective CCM, concentrating CO2 around Rubisco more than 140-times the external CO2 levels, when grown under ambient CO2 conditions. Our findings provide new insights intothe Rubisco kinetics of Cyanobacteria, suggesting that improved Sc/o values can still be compatible with a fast-catalyzing enzyme. The combination of Rubisco kinetics and CCM effectiveness in C. thermalis relative to other cyanobacterial species might indicate that the co-evolution between Rubisco and CCMs in Cyanobacteria is not as constrained as in other phylogenetic groups.
PB Springer
YR 2023
FD 2023
LK https://hdl.handle.net/10630/34160
UL https://hdl.handle.net/10630/34160
LA eng
NO Aguiló-Nicolau, P., Galmés, J., Fais, G. et al. (2023). Singular adaptations in the carbon assimilation mechanism of the polyextremophile cyanobacterium Chroococcidiopsis thermalis. Photosynth Res 156, 231–245. https://doi.org/10.1007/s11120-023-01008-y
DS RIUMA. Repositorio Institucional de la Universidad de Málaga
RD 20 ene 2026