Spectral hole burning study of intact cells of green bacterium Chlorobium limicola.

Spectral hole burning studies of intact cells of the green bacterium, Chlorobium limicola, have proven that the Qy-absorption system of antenna bacteriochlorophyll c (BChl c) should be interpreted in terms of the delocalized exciton level structure of an oligomer. For the first time the 0-0 band of the lowest exciton state of BChl c oligomers has been directly detected as the lowest energy inhomogeneously broadened band (FWHM approximately 100 cm-1; position of maximum, at approximately 774 nm) of the near-infrared BChl c band of 1.8K excitation spectrum (FWHM = 830 cm-1; position of maximum, at 751 nm).