Study on energy transfer between carotenoid and chlorophyll a in cytochrome b6f complex from Bryopsis corticulans.

The excitation energy transfer between carotenoid and chlorophyll (Chl) in the cytochrome b ( 6 ) f complex from Bryopsis corticulans (B. corticulans), in which the carotenoid is 9-cis-alpha-carotene, was investigated by means of fluorescence excitation and sub-microsecond time-resolved absorption spectroscopies. The presence of efficient singlet excitation transfer from alpha-carotene to Chl a was found with an overall efficiency as high as approximately approximately 24%, meanwhile the Chl a-to-alpha-carotene triplet excitation transfer was also evidenced.

Ultrafast carotenoid-to-chlorophyll singlet energy transfer in the cytochrome b6f complex from Bryopsis corticulans.

Ultrafast carotenoid-to-chlorophyll (Car-to-Chl) singlet excitation energy transfer in the cytochrome b(6)f (Cyt b(6)f) complex from Bryopsis corticulans is investigated by the use of femtosecond time-resolved absorption spectroscopy. For all-trans-alpha-carotene free in n-hexane, the lifetimes of the two low-lying singlet excited states, S(1)(2A(g)(-)) and S(2)(1B(u)(+)), are determined to be 14.3 +/- 0.