Energy costs of carbon dioxide concentrating mechanisms in aquatic organisms

0441106 - MBÚ 2015 RIV NL eng J - Článek v odborném periodiku
Raven, John A. - Beardall, J. - Giordano, Mario
Energy costs of carbon dioxide concentrating mechanisms in aquatic organisms.
Photosynthesis Research. Roč. 121, 2-3 (2014), s. 111-124. ISSN 0166-8595. E-ISSN 1573-5079
Institucionální podpora: RVO:61388971
Klíčová slova: carbon dioxide * environmental change * radiation
Kód oboru RIV: EE - Mikrobiologie, virologie
Impakt faktor: 3.502, rok: 2014

Minimum energy (as photon) costs are predicted for core reactions of photosynthesis, for photorespiratory metabolism in algae lacking CO2 concentrating mechanisms (CCMs) and for various types of CCMs; in algae, with CCMs; allowance was made for leakage of CO2 from the internal pool. These predicted values are just compatible with the minimum measured photon costs of photosynthesis in microalgae and macroalgae lacking or expressing CCMs. More energy-expensive photorespiration, for example for organisms using Rubiscos with lower CO2-O-2 selectivity coefficients, would be less readily accommodated within the lowest measured photon costs of photosynthesis by algae lacking CCMs. The same applies to the cases of CCMs with higher energy costs of active transport of protons or inorganic carbon species, or greater allowance for significant leakage from the accumulated intracellular pool of CO2. High energetic efficiency can involve a higher concentration of catalyst to achieve a given rate of reaction, adding to the resource costs of growth. There are no obvious mechanistic interpretations of the occurrence of CCMs algae adapted to low light and low temperatures using the rationales adopted for the occurrence of C-4 photosynthesis in terrestrial flowering plants. There is an exception for cyanobacteria with low-selectivity Form IA or IB Rubiscos, and those dinoflagellates with low-selectivity Form II Rubiscos, for which very few natural environments have high enough CO2:O-2 ratios to allow photosynthesis in the absence of CCMs.
Trvalý link: http://hdl.handle.net/11104/0244208