Özet:

The light phase of photosynthesis is considered a joint operation of 2 functional pigment-protein complexes: a light harvesting antenna, absorbing sunlight in a wide spectral range, and a reaction center, utilizing the energy of absorbed light quanta in photochemical charge separation reactions. These complexes allow converting solar energy to the energy of specific biomolecules with high quantum efficiency. However, before being transferred to reaction centers, the solar energy is stored in the lowest excited state of pigment molecules of the light harvesting antenna that partially convert light quantum energy into heat. These energy losses bring a significant reduction of energy efficiency of photosynthesis in view of a very wide spectral range of photosynthetically active sunlight. In the current study we analyzed the energy efficiency of sunlight harvesting and storing in different photosynthetic bacteria with different absorption bands. We showed that simultaneous exploitation of several such photosynthetic organisms leads to an increased total energy efficiency in terms of harvesting sunlight of the wider spectra. Maximal values of energy efficiencies of the sunlight harvesting and storing system in photosynthetic bacteria and semiconductor photovoltaic cells are compared, and perspectives on practical use of photosynthetic bacteria as solar energy converters are discussed.

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