title: Comparative Analysis of Ultrafast Excitation Energy-Transfer Pathways in Three Strains of Divinyl Chlorophyll a/b-Containing Cyanobacterium, Prochlorococcus marinus.
abstract: Prochlorococcus, a unique marine picocyanobacterium, contains the divinyl- (DV-) type chlorophylls (Chls), DV-Chl a and DV-Chl b, as its photosynthetic pigments. We comprehensively investigated the light-harvesting mechanisms in three strains of Prochlorococcus marinus (P. marinus) at physiological temperature (293 K) by ultrafast time-resolved fluorescence (TRF), steady-state fluorescence, and absorption measurements. These strains differ in their relative amounts of DV-Chl a, DV-Chl b, and carotenoids and in the pigment coupling conditions. All of the strains showed ultrafast excitation energy transfer from DV-Chl b to DV-Chl a, and the low-light-adapted strains, P. marinus CCMP1375 and CCMP2773, exhibited relatively higher DV-Chl b contents than P. marinus CCMP1986. It appears that carotenoid is another important antenna pigment, especially in the low-light-adapted strains (CCMP1375 and CCMP2773), that transfers the excitation energy to lower-energy DV-Chl a.
authors.affiliation: Graduate School of Science, Kobe University , Kobe 657-8501, Japan.
authors.forename: Fumiya
authors.initials: F
authors.lastname: Hamada
authors.affiliation: Graduate School of Science, Kobe University , Kobe 657-8501, Japan.|Kobe University Research Center for Inland Seas , Awaji 656-2401, Japan.
authors.forename: Akio
authors.initials: A
authors.lastname: Murakami
authors.affiliation: Graduate School of Science, Kobe University , Kobe 657-8501, Japan.|Molecular Photoscience Research Center, Kobe University , Kobe 657-8501, Japan.
authors.forename: Seiji
authors.initials: S
authors.lastname: Akimoto
mesh_terms: D002734:Chlorophyll / Q000032:analysis*; D004735:Energy Transfer; D048929:Prochlorococcus / Q000737:chemistry*; D013050:Spectrometry, Fluorescence
chemical_list: D002734:Chlorophyll