Fluorescence Excitation Spectra from Individual Chlorosomes of the Green Sulfur Bacterium Chlorobaculum tepidum.
We performed polarization-resolved fluorescence excitation spectroscopy on individual chlorosomes from the photosynthetic green sulfur bacterium Chlorobaculum tepidum. The experiments were conducted at room temperature and under cryogenic conditions. All spectra showed a strong intensity modulation as a function of the polarization of the incident radiation, and we determined the modulation ratio as a function of the excitation energy. Under ambient conditions this ratio shows only little variation across the absorption band, whereas the low-temperature experiments clearly revealed that the broad absorption band around 740 nm consists of several spectral contributions.
†Experimental Physics IV and Bayreuth Institute of Macromolecular Research (BIMF), Universität Bayreuth, Universitätsstr. 30, 95447 Bayreuth, Germany.
Marc
M
Jendrny
‡Leiden Institute of Physics, Leiden University, Niels Bohrweg 2, 2333 CA Leiden, The Netherlands.
Thijs J
TJ
Aartsma
†Experimental Physics IV and Bayreuth Institute of Macromolecular Research (BIMF), Universität Bayreuth, Universitätsstr. 30, 95447 Bayreuth, Germany.
Jürgen
J
Köhler
antenna complex; chlorosome; fluorescence excitation spectroscopy; light harvesting; photosynthetic bacteria; polarization-resolved single-molecule spectroscopy