The photochemical phase of the bacteriochlorophyll fluorescence induction generated by rectangular shape of laser diode illumination was measured in different organization levels (whole cell, chromatophore and isolated reaction center protein) of carotenoidless mutant of purple photosynthetic bacterium Rhodobacter sphaeroides R-26.1. While the antenna containing species showed large and positive variable fluorescence (Fv) relative to the constant (initial) fluorescence (F0) (Fv/F0 ∼ 4.5 in whole cell), the isolated RC had smaller and negative change (Fv/F0 ∼ -0.6). The variable fluorescence of the cells increased steadily in the function of the age of the cultivated bacterium: Fv/F0 ∼ 2 for young cells and Fv/F0 ∼ 4.5 for old cells while the rise time of the fluorescence induction remained constant (∼ 2 ms). In chromatophore, 7 times higher rate was measured than in isolated reaction center under identical experimental conditions. The results obtained under different conditions are interpreted by an extended version of the Lavergne-Trissl model where the simultaneously measured fluorescence inductions from the antenna and the RC can be separately expressed.
|Number of pages||6|
|Journal||Acta Biologica Szegediensis|
|Publication status||Published - Dec 1 2007|
- Harvesting the sun
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)
- Agricultural and Biological Sciences(all)