High temperature limit of photosynthetic excitons.

ABSTRACT: Excitons in light-harvesting complexes are known to significantly improve solar-energy harnessing. Here we demonstrate photosynthetic excitons at super-physiological temperatures reaching 60-80 °C in different species of mesophilic photosynthetic bacteria. It is shown that the survival of light-harvesting excitons in the peripheral LH2 antennae is restricted by thermal decomposition of the pigment-protein complex rather than by any intrinsic property of excitons. The regular spatial organization of the bacteriochlorophyll a pigments supporting excitons in this complex is lost upon the temperature-induced breakdown of its tertiary structure. Secondary structures of the complexes survive even higher temperatures. The discovered pivotal role of the protein scaffold in the stabilization of exc

SUBMITTER: Ratsep M 

PROVIDER: S-EPMC5758513 | biostudies-literature | 2018 Jan

REPOSITORIES: biostudies-literature